DE1163125B - Method and device for drying moist food - Google Patents

Description

Method and device for drying moist food The invention relates generally to a method and apparatus for Drying various moist food products, including such substances such as fruits, berries, vegetables, nuts, cereals, poultry, meat, fish, wet-set Mixtures of the same and products made with wet dough.

The technical advantages of drying various moist food products, in particular preservation and weight saving are well known. The quality the finished products obtained from various drying processes are replaced by such Factors such as appearance or appearance, color, taste, nutritional value, Degree of denaturalization, rehydration characteristics and nutritional properties. In many cases, poor quality is allowed for economic reasons. Poor quality generally results from excessive heating during longer periods of time, reducing the taste and other heat-sensitive properties are adversely affected, as well as from the oxidation, by which color, taste and nutritional value may be damaged. It also arises in proceedings which cause extensive volume shrinkage and changes in physical shape. In efforts to meet the demand for dried particle products of high To satisfy quality, vacuum evaporators have been used in which Working temperatures on the order of about 60 to 110 ° C under partial Vacuum of the order between 559 and 737 mm of mercury is applied became. With such a device certain moist food products without noticeable impairment of the heat-sensitive or oxidizable components be dried, especially for food products that do not have high Have water content is recommended. However, a conventional vacuum drying device is used the heat transfer to the material subjected to drying with a relative slow speed, especially in those cases where the particles were limited Have contact with each other and due to high water content, thereby reducing the period the evaporation is largely expanded. The masses subject to drying or particles are carried in metal sheets, and in many cases one occurs considerable physical damage to the particles due to overheating and burning on the surfaces in contact with the sheet metal, sticking to the sheet metal by excreting juices and due to changes in physical form and Size. Because of the foregoing and other difficulties, in general assumed that the usual vacuum drying for freshly cut fruits and Vegetables with high water content are practically impracticable.

Freeze drying, which is opposite to vacuum drying, though the product is frozen, is preferred, is good dried in making Products effective with certain materials. Specific disadvantages of this method consist in the relatively high cost of that required for a given capacity Device and in the high cost per unit weight of dried material. According to the observations made, many have freeze-drying made Products also have undesirable properties. For example, there are many products (e.g. the meat of poultry) quite tender or tearable and prone to breakage during processing.

A limiting factor of all technical drying systems of the drying tray type, including vacuum and freeze-drying systems, is that the Heat through a metal surface with which the material is in direct contact stands, is forwarded. When trying to use the trays or plates to feed a quantity of particles to a depth that is greater than one layer, much of the material is not in contact with direct heat transfer, and the heat transfer via neighboring particles is insufficient for practical operation.

It is known that moist food particles are removed by immersion in hot Oil can be drained. If carried out under atmospheric pressure, cause the increased time and temperature factors that occur in this context are undesirable changes in smell, palatability, color, shape and volume. If the oil temperature is increased to shorten the drying time, severe burning occurs. A lower oil temperature tends to boil the material without substantial evaporation. By applying a partial vacuum, the Treatment time can be shortened, however, if the loading conditions are economical from product to oil to be applied, the required time above the practical Limits. There are also unwanted physical changes, such as excessive shrinkage and handling difficulties arise. The, As described above, dried products are characterized by a lack of remoistenability or water recovery, which is characterized by the amount of oil present and the distribution of which is caused in the product.

As a modification of the oil drying method, it is known to use the raw material to freeze this into a mass of hot oil at a temperature on the order of magnitude of 82 ° C or below and then apply a partial vacuum, to carry out the drying, with heat being added to the oil to achieve the temperature level maintain. Although such a process affects the quality of certain products, such as B. meat, can improve something, it is again those listed above Disadvantages including heat damage, uneconomical feed ratio, extended time to complete drying and high residual oil content in the finished product subject.

A general purpose of the invention is to create a new one Drying process which applies to a wide variety of moist nutrients can be used and which many of the drying processes used to date avoids the disadvantages.

Another purpose of the invention is to provide a drying process, which is characterized by rapid heat transfer to the particles to be dried is to be created without causing damage to the same.

Another purpose is to provide a method which Can be applied to a wide variety of fabrics to make products with a reduced moisture content and of the desired value.

Another purpose is to create a new drying process, which by rapid heat transfer from the hot oil to that of the treatment subject subject, a relatively short total treatment time and lack of it from any significant burning or damage to the heat sensitive components is marked, whereby the finished product is of excellent quality.

Another purpose is to provide a drying process which the general identity in the form and size of the individual objects in the finished product or particles that are treated even in cases where the The starting material is soft and has a high water content.

Another purpose is to create a new drying process, which is the physical decomposition of the individual objects or particles that treated, and which prevents the diffusion of sugar, cellulose and other ingredients from the product in the hot oil used to a minimum belittles.

Another purpose is to create a drying process in which high temperature differences in connection with applied partial vacuum be applied, creating a new principle of working with remarkable Benefits and new results is obtained.

Another purpose is to create a new drying process, which removes most of the moisture content in a short time is during which the material is in a hot mixed medium of vapor-liquid phase becoming dehydrated.

Another purpose is to use a new drying method of hot oil in which to dry the individual objects or Particles are specially pretreated to achieve certain desired properties get in the finished product.

Another purpose is to have a drying process tailored to food products to create which by other methods, such as. B. Sun drying, air drying, Vacuum drying, candying, curing or smoking. A another purpose is to provide a drying process using hot Oil, which is used for the production of finished products with a low residual oil content and with new, distinguishing marks can be carried out.

Another purpose is to create a new drying process, in which the starting material can be pretreated in such a way that the volume of finished products is increased.

Another purpose is to provide a new device to carry out of the above procedure.

Another purpose is to create new, dried food products of high quality obtained by the above procedure. at In a typical embodiment of the process, the end product is of high quality in terms of color, taste and nutritional value and becomes light on contact with water and effective to produce a material similar to the initial starting material rehydrated.

Another purpose is the creation of dried food products of high quality, which are characterized in that the individual items or fragments an outer one that is easily permeable to steam and moisture Surface, while the interior of the individual objects is relatively absorbent and is porous. Another purpose is to create new, dried ones Food products with a regulated amount of oil contained therein, which is in a special Way is distributed in the fabric and the flexibility of the fabric in difference contributes to undesirable friability.

Another purpose is to create new, dried food products of high quality made with certain edibles to enhance their usefulness have been impregnated. It can be on dried meat, which is part of its original fat is retained and impregnated with an added fat, be specifically referred to.

The invention is illustrated below with reference to the drawings.

F i g. 1 is a general flow diagram illustrating the process of FIG the invention explained; F i g. 2 is a more specific flow sheet showing the Shows procedures applied to certain types of food products; F i g. 3 Figure 3 is a side elevation, partly in section, showing the apparatus for implementation of the procedure shows; Fig. 4 is a. Side elevation, partly in section, which represents another form of device; F i g. 5 is an accurate representation in section showing another form of device used for restraint the material being dried serves beneath the surface of the oil; F i G. 6 to 16 inclusive are photomicrographs of certain, according to of the invention of manufactured products.

According to the method according to the invention, moist food materials are obtained or particulate food of suitable size and at a low temperature a partial vacuum treatment to terminate a drying cycle subjected, the treatment being a dispersion or distribution of the particles in a mixed phase material or foam consisting of water vapor and hot Oil consists, includes. To open the process, the material can be in an amount of hot oil under an applied partial vacuum. The temperature the oil at the time of first contact is relatively high compared to Evaporation point of water at the partial vacuum presented, for example between 116 and 316 ° C, with the range of 163 to 238 ° C being preferred. at In a typical case, the material is frozen and has a temperature below 0 ° C. Due to the high temperature difference between the material and the hot oil, a rapid heat exchange takes place, creating the outer surface layer of the product heated briefly to the point of vaporization of the aqueous juices present will. The initial stage of the drying process is immediate and rapid Speed of almost explosive violence. A rapidly evolving vapor Forms a mixture of steam under vigorous agitation or vibration and oil, which can also be called foam and a greatly enlarged one Has volume, for example more than three times the normal volume of oil and product. The oil temperature drops immediately and rapidly, and the developing one Steam creates a high velocity stream of steam applied to the evacuation or evacuation Suction units. The surfaces of the material and the outer layers, through which drying proceeds are due to direct contact with the hot oil protected against burning by the rapid development of steam. While this initial phase the material is subjected to certain conditions, which bring about new properties in the finished product, as set out below will.

After the initial initial phase of rapid evaporation, the speed decreases of the steam flow decreases, the foam collapses, and the height of the oil mass returns in return to the vicinity of their starting height. Then (assuming that a minor Moisture content is desired) the drying is done at a lower temperature continued at the end of the process. The main part, for example 75 to 95 %, of the moisture present in the material will be in the short period of time, e.g. B. 1 / E to 4 minutes, largely depending on the particle size and moisture content and initial temperature of the particles, ratio of particle weight to oil weight and oil temperature, the first rapid evaporation phase removed, and the remainder Moisture (apart from the residual moisture value) is at a lower temperature level removed. In general, the total time in hot oil is below the initial charge partial vacuum is relatively short and in typical cases can be of the order of magnitude from 7 to 40 minutes.

When the moisture content of the material is at the desired level can be any of a number of processing methods can be applied depending on the character of the desired end product. One method is that the vacuum is broken after the free Oil was stripped from the product, followed by some additional oil can be removed by centrifugation. However, it will be usable for most of the Preferred starting materials, a general separation between the free oil and effecting the dried material and then centrifuging the material to subject, everything being done under partial vacuum, whereupon the Vacuum is removed. Such a process leads to certain new and desirable ones Properties in the final product.

It should be noted that the product has a tendency towards the end to be buoyant during the initial phase and while maintaining the vacuum, but that if the vacuum is released before the oil is removed, it will sink into the oil is. Separation can be achieved before the vacuum is broken by using the Oil beneath the floating material is removed, eventually causing a settling of the material occurs on a sieve through which the oil can be drawn off.

The flow sheet of FIG. 1 illustrates a method for performing the method according to the invention. The moist, edible food material to be dried is first subjected to preparatory operations in step 10 , the nature of which depends on the material to be treated and the desired character of the finished product. In general, preparation or pretreatment includes cleaning and, if the individual items are of significant size, cutting, disassembling or otherwise reducing the items into masses or particles of suitable size for processing. The material is then quenched to create a free flowing, frozen mass of material. Such material can be stored at temperatures on the order of -40 to -6.7 ° C until it becomes tangled when fed into the process. Conventional freezing methods can be used, such as e.g. B. a process known as "individual rapid freezing".

In general, it is desirable that the particles be sized and Weight are relatively uniform. According to the observations turned out Particles less than about 10 grams in weight are considered well suited for the process and gave a good surface area to weight ratio.

The invention is applicable to various types of nutrients, including fruits and berries, vegetables, seasonings, meat, poultry, Sea food, cereal grains, dried fruits and formulated products, being all to form quenched particles suitable for processing can be prepared. A great variety of types of fruit can be made according to the Processes according to the invention are treated including peaches, apricots, Pineapples, cherries, bananas, grapes, dates, gooseberries, blueberries or the like. Usable vegetables include peas, carrots, potatoes, celery, cabbage, bean sprouts, Onions, peppers, sweet potatoes, cereals or the like. Types of meat that can be used include beef, pork, lamb, processed meat, such as salted Beef sirloin, smoked pork or the like. With regard to poultry, chicken, Turkey, pheasant, duck or the like. Mentioned. With regard to sea food, both fresh as well as cooked prawns, tuna and other fish as they normally are be put on the market, oysters, clams, lobsters, crabs or the like. Listed. Mushrooms, water chestnuts and various spices and herbs can be used as cooking seasonings be mentioned.

The larger fruits like peaches can be peeled, pitted and in Cut or dice pieces no more than about 1.27 cm thick. Smaller fruits, such as cherries, blueberries, and grapes, can be used without any reduction cleaned and frozen in size.

Fresh vegetables can be made using common methods, such as used in the frozen food and canning industries and be prepared. Before freezing, bleach can be applied to the reduce enzymatic activity to a minimum. Multiple perforation or Scoring can be done before or after freezing such substances as peas, Chinese Pea pods or the like can be used. Here, too, the components if they are of significant size, into particles (e.g. thin slices or cubes) scaled down to a size suitable for processing.

Types of meat, such as beef, pork or t lamb, can be prepared by cutting and trimming to suitable size, after which they are boiled, dried and frozen. Poultry such as chickens and turkeys, etc., can, by cleaning and cooking, removing the meat from Leg and skin are prepared and cut into pieces of suitable size, whereupon the meat is frozen. Softening treatments such as slow freezing and; or intermediate thawing and freezing again, can be applied.

Seafood, such as shrimp, cod or other fish meat, can be prepared by cleaning, boiling and flaking with subsequent freezing will. In some cases, cooking can be omitted.

Seasonings, such as B. fresh mushrooms, water chestnuts od. DgL, can through Cleaning, cutting and subsequent freezing must be prepared. If the source material of this class is in dry form, such as. B. dried mushrooms, there may be cleaned and partially rehydrated in the freezer.

As indicated above, some starting materials can be used after others Procedure have been processed. For example, materials such as cherries, subjected to processing to produce a maraschino-type product have been. Pork can be used as ham or beef as cured beef be preserved. Materials, such as cereals, chickpeas (garbanzo beans) or Japanese tree fungi can be air-dried or sun-dried, causing them to rehydrate before freezing. Dried fruits such as dates, peaches or apples, can be partially dried by air or sun drying. Vegetables, like cucumbers, may have been preserved by pickling them in vinegar.

Although the individual rapid freezing process for production a free flowing material is preferred, it has been found in some cases to be satisfactory to freeze in the form of a dough, provided that such Dough masses quickly break down into individual frozen particles when the dough is in the hot oil is immersed.

Provided that the food material has been prepared and quenched to a temperature below 0 ° C, and preferably on the order of -40 to -6.7 ° C, which in most cases will freeze out, it will be in with the hot oil Stage 11 contacted, preferably by depositing a measured charge of frozen material in a predetermined amount of hot oil, the oil being subjected to a partial vacuum.

The amount of frozen material (by weight) introduced into a given amount of hot oil depends mainly on the initial temperature of the oil and, accordingly, on the temperature difference between the quenched or frozen material and the oil. With higher oil temperatures, larger amounts of quenched material can be applied. For example, with an initial oil temperature of around 116 ° C, the ratio in a typical case can be 1.81 kg of frozen material (e.g. at -15 ° C) for every 45.4 kg of oil, while with initial oil temperatures in the range from 163 to 227 ° C, the ratios can be in the range from 3.18 to 13.6 kg of quenched material per 45.4 kg of oil. The introduction of the quenched material into the hot oil with the ratios of the order of magnitude mentioned above serves to rapidly reduce the temperature of the oil from its initial value to a lower level on the order of 54 to 110 ° C. In addition, the rapidly evolving steam is mixed with it the hot oil and creates a mixed medium of vapor-liquid phase or foam with a volume far greater than the original oil mass. This medium envelops the material exposed to drying and causes the material to be dispersed over the extended space which the medium occupies. The rapid drop in oil temperature is due to the rapid evaporation of moisture which results from the high rate of heat transfer from the mixed phase medium to the food material. The extent of the oil temperature drop is determined by the amount of sensible heat consumed in the evaporation of moisture.

As mentioned above, at the end of the initial phase, which is characterized by the generation of a mixed steam-oil medium, the medium or foam sinks and then the process is continued at a lower temperature in order to obtain a desired low moisture content. At the end of the drying process, the products obtained are separated from the free oil in stage 12. This is done while maintaining the predetermined partial vacuum by separating the oil from the floating material, whereupon the material settles on a sieve through which the oil is drawn off. The vacuum is then released and the product is removed from the treatment chamber. This. Process serves to obtain end products with a significant amount of oil content resulting from the process, for example an oil content which can be in the range of 50 to 60% on a dry solids basis. Such an oil content can be reduced somewhat by centrifugation, whereby. the material is treated at a temperature level above the melting point of the oil, whereby the oil easily leaves the pores of the dried product. With this process, products can be obtained with oil contents which, in a typical case, can be in the range from about 40 to 50%, based on the dry substance.

Some experimental changes were made in the process, including changes in the moisture content of the starting material and changes in the size of the particles. In general, for low moisture materials, the feed ratio can be increased to achieve the same temperature drop over the same period of time. In general, the charge (by weight) for a given amount of oil and for a given initial oil temperature should be such that it immediately raises the oil temperature to a temperature of the order of magnitude in a short period of time (e.g. 1/2 to 4 minutes) lowered from 54 to 110 ° C; During this period the thawing of the frozen material takes place. An initial frozen state of the material makes a number of more desirable ones. Characteristics. In particular, there is physical rigidity for the separation of the particles introduced into the hot oil, even though the moisture content may be high. This enables easier handling and loading of a mass of material into a hot oil mass without breaking and crushing. It also enables a heat transfer relationship with the surrounding hot oil for each individual frozen particle, with uniform evaporation from all of its exposed surfaces. During the initial phase of rapid evaporation, thawing takes place at the same time as evaporation. That. Thawing and evaporation begins on the outer layer and progresses inward. In this way, a rapidly decreasing frozen core remains during the initial phase of evaporation, which gives rigidity and helps maintain the original physical shape. It is likely that evaporation will not take place directly from the frozen state, but only after some defrosting has taken place. The speed of defrosting therefore serves as a regulating factor for the speed of evaporation. The receding frozen core also keeps some of the mass stiff and cold as thawing and evaporation proceed. The defrosting or defrosting is completed within the period of the rapid initial phase of evaporation.

The initial rapid evaporation from the outer layer proceeds continues inwards and develops a rapid stream of steam to the outside, which leads to it tends to have a complete breakdown or excessive shrinkage of the particles as evaporation proceeds.

Although the vapor evolved through the outer layer of the particles draining away under inflation of the tissue when the moisture evaporation inward as it progresses, the tissue is not broken down into its constituent parts and remains in the particle without any significant spatial reorientation. The extent to which The tissue can be torn or altered, depends on the starting material away. The soft and sponge-like tissue found in juicy vegetables such as celery, will be found to a significant extent. changed, whereas the cell tissue of a material such as cooked beef is not significantly altered. There evaporation takes place in the outer layer of each particle before evaporation if the person has advanced to the intermediate level, there is a tendency towards training a stiffening of the outer tissue before the frozen core disappears, and this stiffer outer layer serves to maintain the general shape of the Particle and retention of the inner tissue within by the outer Layer of certain space. The outer layer remains with the developing, overheated one Accessible to water vapor and does not form matted and relatively inaccessible skin. Such a surface skin, which is usually used in other drying processes found practical and referred to as shell hardening is for many reasons uncomfortable, including the fact. that they are thermal insulation and moisture barrier forms, which the heat transfer and moisture development prevented and modified the physical appearance of the final product and rehydration inhibits.

The freezing temperature of various water-containing food products varies somewhat depending on the character of the aqueous juices. In general can contain most of the water-containing nutrients to which the process can be applied is deep-frozen at temperatures within the range of - 17.8 to - 4.44 ° C will. The treatment of the nutrients before drying, e.g. pre-drying or added sugar, serves to increase the dry matter content and to reduce it the freezing point to temperatures which in some cases less than -17.8 ° C can be. It can be specially made on sun-dried dates or glazed Cherries are referred to. It is common in the frozen food industry common to freeze to a temperature of around - 30 ° C and then at temperatures well below freezing, for example between -40 and -6.7 ° C. This procedure can also be applied here, with yourself the material when removed from storage is within this temperature range and does not increase its temperature significantly before the hot oil is brought into contact. Although freezing has certain advantages, you can Substances with low freezing points without freezing to a temperature below 0 ° C. Such quenching sees a large temperature difference to promote rapid heat transfer. The natural strength and stability such substances tend to protect them against damage.

Slow freezing or defrosting and repeated freezing can occur can be applied to substances such as B. meat, poultry and fish to soften.

In those cases where high oil temperatures are used, e.g. B. 204 to 316 ° C, the material can be immediately prior to introduction into the oil very low temperatures, for example to -40 to -51.1 ° C, are quenched, z. B. by dry ice or another coolant. Under such conditions the initial speed of heat transfer is accelerated. This method can advantageously be used for substances with a very low solids content, e.g. B. Celery, applied, if desired, the moisture as soon as possible to remove.

Although the evaporation point of moisture in most moist nutrients is well below 54 ° C, with a vacuum on the order of 55.9 to 73.7 cm of mercury, it is desirable to operate the process so that the oil temperature does not fall below this Value falls. The temperature level to which the oil falls in the first phase of rapid heat transfer is largely determined by the initial temperature of the oil, the temperature of the frozen material, the ratio between the weight of the material and the weight of the oil, the degree of before and after Introducing the loading vacuum maintained and the original moisture content and size of the material is determined. Preferably, the thermal equilibrium is such that the initial rapid drop in oil temperature does not go below about 54 ° C, which subsequently, provided that a moisture content of the order of 1 / E to 5% in the finished product is desired, a temperature level which between 77 and 110 ° C, optimally about 90 ° C, is maintained for the remainder of the operation. In exceptional cases, temperatures above the range just given, e.g. B. up to 116 ° C, if some browning is not harmful, for example with fish, meat. Depending on the extent of the temperature drop that tends to take place in the initial phase, some heat can be added to the oil to ensure a suitable temperature level for the remainder of the operation. Thus, in the course of the initial phase, heat can be added, for example by steam jacketing the tank or vessel in which the oil and charge is contained, with the result that the amount of temperature drop is reduced. This heating can be continued after the initial phase in order to bring the temperature to a desired level. Another method is to add heat by circulating oil through an external heat exchanger. The preferred method is to withdraw some of the starting oil at or near the end of the initial phase and reintroduce fresh hot oil at a temperature such that the resulting oil mass temperature is maintained at a desired level for the remainder of the operation . The advantages of the last-described method are explained below.

The immediate and rapid temperature drop in the initial phase limits the length of time during which the particles of material are bound to the oil at a temperature which is normally in the burning range. Likewise, the oil is in the form of a foam during the limited time of such a connection and therefore does not have the burning effect of a denser, liquid phase body at the same temperature. The remainder of the operation, which requires a longer residence time and during which the material is in direct contact with the oil at its normal or almost normal density, is carried out at a lower temperature in order to avoid burning. In typical cases, the outlet temperature of the oil is around 90 ° C.

Experiments have been carried out showing the benefits and new results confirm that by introducing moist food material into the hot oil in quenched and under a partial vacuum. Under the same conditions, but with the introduction of the starting material at room temperature, if there is noticeable physical damage to the product, e.g. B. Discoloration, burning, disintegration of the cell structure into its components, different Degrees of disintegration or dissolution into the oil and collapse of volume. The magnitude of these effects is largely dependent on the oil temperatures and the Character of the source material. High initial temperatures of the oil, which with the temperatures used in the process according to the invention are comparable, can not be applied, causing lower temperatures and expansive Working hours become necessary. if the moist food material quenched and frozen and then introduced into the oil, with charging and oil are under partial vacuum, the process is changed and the Quality of the end product largely improved. Under suitable conditions can Discoloration and burning are completely eliminated, and these are desirable Results can be achieved with a work flow that is practical and is relatively effective. Contrary to expectations, the deterrent actually increases the rate of moisture removal, with the other conditions being the stay the same. In a series of experiments, a single batch of fresh, Unfrozen peaches returned to 501 / o moisture in 10 minutes; however, when frozen and the same conditions of initial oil temperature and partial Vacuum (according to the invention) were exposed to the moisture content reduced to about 50% in 5 minutes and to 29% in 10 minutes. These results cannot be adequately explained, but will be of better heat transfer due to the greater difference between the temperatures of the oil and the material as well as better regulation of evaporation from the quenched and frozen Material attributed and attributed to the fact that the surface tissue does not collapse down forming a heat-insulating skin.

With ordinary evaporation, moisture is released from the surface removed by evaporation with the result that a continuous redistribution the moisture content with a continuous concentration of the aqueous Juices is obtained. In the method according to the invention, provided that that the material is frozen, practically an immediate transfer of ice in the vapor phase before (probably with momentary passage through the liquid phase), and therefore there is no redistribution of the juices. In this procedure there is likewise little opportunity for the cell structure or the tissue with which Juices to be moistened in the liquid phase.

Inside the hot oil and especially during the initial period the particles should be present uninhibited. As mentioned above, the rapid Removal of water vapor accompanied by the generation of a mixed foam phase, d. H. of a water vapor-oil mixture, which envelops the particles, and of a relatively violent agitation or shaking action of this medium, which the particles keeps moving and distributed in the foam body and generally good Contributes to heat transfer.

Using known types of evacuation and steam condensing devices (e.g. a water spray compressor and a mechanical pump or an ejector pump) it is feasible to have a partial vacuum on the order of 55.9 to 73.7 cm of mercury maintain. Assuming that the initial vacuum is of the order of magnitude 66.0 to 71.1 cm of mercury can be added immediately after loading of frozen material brought into the hot oil, the speed of the Steam flow from the foam obtained be such that the capacity of the evacuation devices something is burdened. In this case the Tenl vacuum can be temporarily reduced be, for example, to 63.5 cm of mercury. Such a degradation the vacuum reduces the stress in the template and also serves the purpose the prevention of such a rapid flow of vapor that excess amounts of oil could be brought into the condenser. Towards the end of the initial phase and during the following part of the process a higher vacuum, for example from 68.6 to 73.7 cm, can be applied and maintained. In the practical implementation when operating a technical device can be the presented Vacuum gradually increased as the moisture content of the material decreased will.

As mentioned above, during the initial stages of the procedure, z. B. during the first 1 / E Iris 4 minutes, during which rapid evaporation stafndet, the material in a mixed phase (e.g. steam-oil) of greatly enlarged Volume envelops and the oil temperature is rapidly reduced. During this phase becomes a major part of the initial moisture content, for example between 50 and 95%, optimally between 75 and 90%, removed. In some cases, products with a residual moisture content of the order of 15 to 30% is desired. Such products can be provided that they are sufficiently strong the drying process after setting the desired moisture content finished, which may be the case shortly after the end or at the end of the initial phase can. Evaporative cooling can be applied to the products as described above will. Likewise, as described above, centrifugation or preferably can be applied under vacuum as described below.

The length of time required to produce dried food products with a low moisture content ranging from about 1 / E to 5 0/0 depends on a number of factors, including the nature of the source material, the pre-treatment of the material, the initial temperature of the oil in stage 11, the Amount of starting material in relation to the amount of oil (based on weight) and the temperature to which the feedstock is quenched, as well as the Value of the applied vacuum. However, for a great variety of humid, frozen foods and at temperatures and a vacuum in the above The order of magnitude given is the duration of the treatment for the production of moisture contents in the range of 1 to 511 / o in. on the order of 7 to 40 minutes, the optimal time is between 10 and 25 minutes.

Instead of using the procedure described above to remove free To apply oil at the end of the working cycle, it is preferred to use the free oil from remove the product and then centrifuge the product, while all the time a, partial vacuum is maintained. Following this procedure you can Products with an oil content of between 20 and 40% dry matter basis with reference to the oil content resulting from the process obtain will. As will be explained in detail below, this method also leads to new products with excellent marks. By reference in particular the way in which the oil content is regulated and distributed in the product, there are certain advantages due to such a distributed oil content at the specified level achieved and certain disadvantages caused by the method described above are obtained, avoided.

A wide variety of oils and fats can be used. For example various oils and fats of vegetable or animal origin can be used will. Examples of vegetable oils are corn oil, cottonseed oil, rice bran oil, soybean, Olive, peanut, coconut, sesame, tomato seed oil or the like. Examples of animal Oils are fish oil, beef tallow, pork fat, butter fat or the like. In general, it is it is desirable to use oils or fats which are refined to a point in which they do not impart an undesirable smell or taste to the product. The so-called hydrogenated oils have been used with good results, for example hydrogenated cooking or shortening fats. In general, oils tend to be higher Melting points such as B. cottonseed flakes (melting point about 66 ° C), in addition, to be retained to a small extent by the finished product.

In addition to the oils and fats listed above, for some Products used edible waxes, which at temperatures in the order of magnitude of the stable liquids used in the method according to the invention. For example, natural or refined beeswax has been used with good results used. Such a wax can be used in various amounts with a suitable oil or fat, thereby modifying certain physical characteristics of the oil will. In particular, the introduction of wax increases the melting point of the oil and increases its viscosity. This also gives a medium which is more stable and therefore more suitable for reuse, the easier it is to use Removal of solid matter can be filtered and that tends to get in to a lesser extent to be absorbed by the product. The greater stability tends to increase the service life and provides better protection for the product to atmospheric moisture. Jojoba wax is another example which with oil, e.g. B. with hydrogenated cooking fat, can be mixed and in the same Modifies the oil by raising the melting point, lowering the smoke point and makes the oil more stable and more suitable for repeated reuse.

The expression "Ö1"; as used herein includes oils, fats, and Waxes, all of which are esters of fatty acids, and mixtures thereof, with and without hydrogenation, discoloration, deodorization or other refining treatments. It is also understood to mean materials that have characteristics such as oils and Have fats, are edible and have sufficient stability to withstand the conditions which they are exposed to in the method according to the invention.

The oil preferably has a melting point above room temperature, for example between 39 and 66 ° C. Oils with odor, such as. B. butter oil or natural animal fats, for example chicken fat, can be used in certain Cases used to impart a desired odor. Special odor components can be introduced into the oil, with some of this odorous substance in the material subjected to the treatment is retained. At temperature heights which reach up to 227 ° C, and with a partial vacuum applied are the more significant animal and vegetable oils show no serious breakdown or changes subject in their molecular structure. Certain oils are for technical use Use at temperatures in the range up to about 316 ° C under vacuum sufficient stable.

In general, it is preferred to use the highest temperature with which the stability of the oil used, the character of the material to be dried and corresponds to the device used. As mentioned above, results a high initial temperature of the oil a high temperature difference between the Oil and the material to be dried, quenched, damp, which results in a very rapid process and effective heat exchange is brought about. It also enables one high feed ratio, or, in other words, a relatively large amount a quenched material can be introduced into a given amount of oil, which gives a good production capacity and a relatively short drying process will. In addition to the above, the application of a large temperature difference appears to produce desirable properties in the finished product. It will be practical and considered desirable, in some cases oil temperatures as high as 316 ° C should be used under the application of vacuum, provided that the oil is sufficiently stable is and the device is of the type to allow a corresponding regulation. The preferred range for the initial temperature of the oil is between 163 and 227 ° C, with about 204 ° C believed to be the optimal value.

Although the method used regarding the type of used Oil is not critical, in some cases it is desirable to use an oil that is natural There is a relationship to the product to be treated, to choose what the oil remaining in the final dried product is considered a natural additive can be. For example, when drying pork, pork fat can be used can be used with or without hydrogenation. Likewise, beef suet can be used for beef and chicken fat can be used for chicken. Natural fish oil can be used for that Drying fish, coconut oil for fresh coconut, olive oil for processed Olives, tomato seed oil for tomatoes, corn oil and other suitable grain oils for Cereals are used. For the drying of meat it turned out to be desirable to use a fat from the areas of the internal organs, which is known is that it is a little harder than a fat near the skin.

Depending on the particular food material to be treated Components from the material get into the oil. So can at the end of the operation the oil contains such components as sugar, farinaceous substances such as starch, color components, Have accumulated cellulose fibers and skin material. Such Fabrics can from the oil by known methods, such as. B. sedimentation, centrifugation and filtering, leaving a clarified oil in a condition for reuse will be produced.

For economic reasons, it is generally re-used of the oil is important. The suitability for reuse depends on the stability of the oil under the conditions to which it is exposed and the degree of lightness with which the oil can be brought into a condition for reuse.

The properties of the end product, especially color and taste, can be affected by dispersed solids accumulated in the oil. To avoid the harmful effects of such accumulated solids or to bring it to a minimum, it is preferred to do one during the operation To replace part of the contaminated starting oil with hot, clarified oil. That, hot clarified oil can have such a temperature that a heat exchange, like described above, causing the temperature of the oil mass during of the rest of the workflow is increased to a desired level. The amount such substitution can be varied according to needs. if the substitution reaches 100%, the product becomes in the course of the remainder of the workflow less by any properties of the starting oil. affects which in the initial phase were obtained. That which has been substituted for the original oil Oil can be fresh oil that has been heated and deaerated, or an in oil used in a previous work step, which can be removed, for example, by settling, Centrifuge and filter clear, heated and vented. With or without an oil substitution at the end of or near the end of the initial phase of the operation can be all or part of the used after the initial part of the workflow Oil mass must be removed before the workflow is completed and others. Oil used will. The temperature of the imported oil should be such that a gives the desired temperature for the whole oil mass. Such an oil does not need to have the temperature stability of the oil used first, it can be chosen so that the finished product has the desired properties, such as taste or the like., be awarded.

At the end of the centrifugation run under vacuum as above described, and before the vacuum is released, various substances can dem Product are fed, whereupon the vacuum is removed. This results in a Penetration of the supplied material into the pores of the product. Liquid impregnating Ingredients that can be applied in this way include liquids, which flavorings, vitamins or the like. Contain. In this way it is feasible before opening the vacuum at the end of centrifugation, place the product in the centrifuge immerse in a liquid treatment medium. When the vacuum is released, the liquid is pressed into the pores of the product, allowing good penetration is obtained. The product can then be drained and centrifuged to remove the free impregnation liquid. The liquid impregnating Ingredients which can be applied in this manner include oils or Fats,. Aqueous liquids that contain flavor components, alcoholic Liquids, concentrated sugar syrups, preservatives, plasticizers Enzymes, stabilizers or the like. The impregnation of dried Chicken with chicken fat, gelatin solution, or both.

It is possible in addition to the impregnating ingredients specified above to use liquid solvents, which by means of atomization or immersion the material after centrifugation under vacuum, and before the vacuum is released will be applied. The release of the vacuum then serves to remove the liquid To cause solvents to penetrate the pores of the product. A solvent can be used in this way as a medium for the introduction of certain components into the Product, for example determinable vitamins and enzymes, can be used. Afterward the excess solvent can be removed by centrifugation and / or evaporation will.

Substances in the vapor phase can also be applied to the finished product before the vacuum is broken, such as. B. aromatic. Flavors. In this way, if a spice vapor is introduced into the room, which is occupied by the centrifugal drum, at the end of or near the end of the centrifugation cycle, but before the rotation of the drum has completed and before or during opening the vacuum, some aromatic or volatile flavor components to penetrate into the pores. In place of steam, finely distributed or spray droplets of a normally liquid wort applied in the same way will.

A feature of the process is that the evaporation in Absence of atmospheric oxygen is carried out '. That's why the Oxidation of constituents of the food is kept to a minimum. To the To prevent oxidation during storage, in certain cases one or several antioxidants are introduced into the treatment oil, thereby reducing each slight oxidation, which can occur during evaporation, is prevented. Assuming there were such antioxidants in the final processing oil are used, the inhibitory effect is due to the presence of something remaining Oil continued in the finished product.

In the more detailed flow chart in FIG. 2, after preparation and freezing in stage 20, the moist food is deaerated by subjecting it to a partial vacuum, and then a batch of this material is placed in a hot saucepan in stage 21 with the oil similarly under a partial vacuum at a time the introduction and during the work process. As stated above, in this initial phase of the work, a mixed steam-oil medium is produced in which the particles are dispersed, this medium being subject to movement and having a volume far greater than the original hot oil mass. The mixed Phase medium or the foam collapses towards the end of step 21, as indicated in step 22. In step 23, part of the first hot oil is removed from the material and replaced by a second clarified hot oil which is at a lower temperature, see above that the total oil mass after the substitution is at a suitable temperature level for the remainder of the operation.Drying proceeds to completion in step 24. In step 25, free oil is drawn from the product while the vacuum is maintained, and the product is centrifuged while maintaining the vacuum in step 26. In step 27 the product becomes an evaporation quench g exposed. Evaporation quenching refers to a drop in temperature of the product due to the removal of sensible heat to add heat of vaporization from moisture within the material. Such cooling takes place to some extent immediately after the product has been removed from heat exchange contact with the oil . Preferably this is increased by increasing the applied vacuum (ie further reducing the pressure) for a short period of time. For example, if the vacuum applied in the previous stages was on the order of 63.5 to 73.7 cm of mercury, the higher vacuum could be in the range of 73.7 to 75.5 cm of mercury for a period of that order from 30 to 60 seconds to reduce the temperature of the product to a level below about 54 ° C, and preferably below the melting point of the retained oil present. In stage 28 the vacuum is broken and the product is removed. Step 29 shows the application of an impregnation medium to the centrifuged material before the vacuum is released, and the vacuum is then released in step 30 to allow the impregnation medium to penetrate the material. The final product obtained is of the type which has been impregnated with a material other than the oil used in the process. The excess of free impregnation medium, such as. B. a liquid can be removed by draining, drying or further centrifugation in step 31.

If the 01 tends to premature solidification during centrifugation due to the cooling by evaporation, the vacuum applied may be reduced during this stage, examples; for example from 71.1 to 61.0 cm of mercury.

If a product with a higher moisture content is desired, the removal of free oil in step 32 can take place at step 22, followed by centrifugation under vacuum in step 33, quenching by evaporation in step 34 and the vacuum released in step 35 to give a final product produce.

Another method of cooling down before breaking the vacuum is to put a measured amount of water in the evacuated space in which the product is dispensed after the free oil has been removed therefrom is. The amount of water can e.g. B. between 10 and 100 percent by weight of the dried End product. This water immediately turns into superheated steam, and the steam flows to the product without increasing the moisture content of the product Condensation device. The heat of vaporization of the water is from the walls taken from the device in which the product is distributed, as well as from the product itself. It is therefore used to reduce the temperature of such metal parts the device, which are in the vicinity of the product, for example a centrifuge drum and adjacent walls and the final temperature of the product. A low exit temperature generally results in greater product stiffness and volume after releasing the vacuum. This cooling just described can end at or near the end of centrifugation, with or without applying a higher vacuum as described above can be applied.

F i g. 3 explains a simple device which can be used to implement of the procedure can be used. It consists of a boiler or container 40 of considerable height, which is provided with a removable cover 41 and with a inner, perforated (perforated) drum 42 is provided. Corresponding the figure is attached to the drum at the lower end of the Stpbes 43, which is rotatably and slidably extends through the lid.

The upper edge of the drum is provided with a ring 44, as shown, which can be made of resilient synthetic material. Line 45 connects the container to suitable condensation and vacuum pumping devices. The tubes 46 and 47 are used to introduce and Ent fesnen the oil charges. These tubes are connected to external oil storage tanks and heat exchangers. These external devices may also include an oil clarification device, e.g. B. a centrifuge for the removal of solids contained therein and a clarifying filter. The container may be provided with a steam jacket for direct heating (not shown).

It is desirable to provide means within the container 40 to to remove the particles during the second phase of the lower temperature operation to press under the oil surface, because at this point the buoyant particles tend to float as a thick mat or layer on the surface of the oil, causing some particles to rise above the oil line. That's why it's one with holes provided barrier screen 48, which has a perforated raised edge, in the container by means of suitable devices, such as. B. the cables 51, which by turning the crank of winch 52 twisted or untwisted, adjustable hung up.

The in F i g. The apparatus shown in Fig. 3 is as follows operated. The lid 41 is removed and a load of frozen material is removed inserted into the centrifuge drum 42. In the lower part of this container will be introduced an amount of oil at its upper temperature level. The centrifuge drum is now introduced into the upper part of the container together with the sieve 48 and the lid attached. The inside of the container is subjected to a relatively high vacuum evacuated from the order of 71.1 to 73.7 cm of mercury. To this At the time, the oil takes up a small part of the container space, for example an eighth in the lower part, a. After a short holding period during which the frozen material is vented, the drum 42 becomes the bottom of Lowered container, whereby the frozen material is introduced into the oil and the Particles are released to move freely. A mixed phase of steam-oil-medium is generated immediately, the surface height of which is a multiple of the original The amount of oil mass increases, and this is caused by a rapid flow of steam through conduit 45 accompanied to the suction devices. If the oil is pretty much at the end of the first Phase sinks, there is a tendency for the buoyant particles to form a layer or mat to float on the surface of the oil. At this point, sieve will be 48 is applied to keep the particles submerged, and it becomes mounted at a height in which its horizontal part is below the oil level lies, while the edge 49 extends over the oil level. This is for retention of the particles in the submerged state, creating a good touch of each Particles with the oil is ensured. The edge 49 prevents the particles from falling Ascend around the edge of the sieve to the top. As described above, some of the first oil can be removed from the container at the end of the first phase of the operation removed and additional hot oil can be used. At the end of the drying process the product is removed from the oil by lifting the centrifuge drum or by removing the oil through line 47. After the free oil has run off, whereby the vacuum is maintained, the drum 42 is rotated, causing further Oil from the surfaces and the porous interior of the product by means of centrifugal force Will get removed. After the end or near the end of centrifugation, this can Vacuum can be replaced by evaporation for effective cooling, whereupon the vacuum drained and the lid 41 removed to remove the product.

The in F i g. The device shown in FIG. 4 can be used to carry out the in F i g. 2 outlined procedure can be used. She has a different one Arrangement for the introduction and removal of the feed material. This device consists of a container 61 of considerable height in relation to its diameter (e.g. height of 10 times the diameter). The lid 62 is like with a winch 63 in Fig. 3 provided, which for raising and lowering the locking screen 64, accordingly the sieve 48 of FIG. 3, serves. A hopper 66 is outside, the Container 61 is attached and through one side of the container through the feed screw housing 67, which contains the feed screw 68, connected. The container 66 is, as shown, connected to suction devices by line 69.

The container 61 is provided with steam condensation and suction devices or evacuation devices connected via pipe 70. The pipes 71 and 72 are used to introduce and remove oil. The lower end of the tank 61 is standing in communicating connection with a removable housing 73 via the valve device 74, which can be a throttle valve. The housing 73 encloses one with holes provided centrifuge drum 75, which is intended to rotate the product. The lower part of the housing 73 is connected to a pipe connection 76 for the discharge of oil attached to an oil storage and recovery system. Housing 73 is also through Pipe 77 connected to suction or evacuation devices. The opening of pipe 78 allows atmospheric air or other gas to enter the housing at the end of the operation.

The device of FIG. 4 can be operated as indicated below. The charge of quenched material to be dried is placed in container 66. With the throttle valve 74 closed, the initial amount of hot oil is brought into the lower part of container 61. The pipeline 70 is, as described above, connected to condensation and evacuation devices. Before the work process is started, the frozen product is subjected to a partial vacuum and thereby vented. The partial vacuum is applied to the container 61 in the same way. The screw feeder 68 is then operated to discharge the load into the container 61. As the material is dispensed into the upper part of this container 61 at a practically steady rate, it falls continuously downwards towards the lower part of the container to come into contact with the hot oil. Preferably, the introduction of the frozen takes place. Materials over the course of a considerable period of time, for example between 7 and 3.0 seconds. Immediately after the first contact of the frozen material with the hot oil mass, a rapid heat transfer with vigorous evaporation takes place. The speed of vapor development is so rapid that it creates a foam-like medium with the oil, which contains an expanded mixture of vapor and liquid oil and which rises in the container like a column expanding above the surface of the oil mass. At the time of, or shortly after, the completion of the introduction of the feed, virtually all of the oil is in this mixing phase, or, in other words, virtually no oil remains in the liquid mass above valve 74. The container should be of sufficient height so that the mixed steam - (> 1-modium does not extend into the tube 70. In a typical: example, the height of this column can be between G and 10 times the original height of the oil masw. During the continuous introduction of the frozen material feed, the frozen particles fall down through the mixed phase of the steam-oil column. This serves to control the foam column and steam flow rate without developing an excessive height column or steam flow rate which cannot be processed by the receiver or condensation system. The steam-oil mixture is cooled by contact with the incoming frozen material, and the steam going to the receiver is brought to a lower temperature level. The introduction of the materials via a vox-determined The loading period also results in a reduced Ve ration of product to oil at the beginning of the operation. The feature just described enables economic ratios between the charge weight and the weight of the oil used, since it controls the development of a column of foam and the development of steam during the first part of the operation, at which time the development of moisture, the generation of steam and steam flow tend to be particularly violent.

As previously described, the initial phase is accompanied by a rapid drop in oil temperature. When the column of mixed steam-oil medium collapses, the screen 64 is opened as in the apparatus of FIG. 3, whereby the remainder of the operation is carried out so that all of the material is kept immersed in the oil. At this point, some of the oil can be removed and replaced with clarified hot oil as in the device of FIG. 3. When the product has reached the desired moisture level, the throttle valve 174 is opened to drain the oil and dried material into the housing 73 and the perforated drum 75. At this point the housing 73 is under the same partial vacuum as that applied to tank 61. The oil is now removed from the housing 73 through line 76, including the oil draining from the product. The drum 75 is then rotated which removes some of the residual free oil. At the end of or near the end of the centrifugation operation, the partial vacuum applied to the housing 73 can be increased. For example, if the partial vacuum is on the order of 68.6 to 72.4 cm of mercury, the vacuum in housing 73 is brought to a value on the order of 73.7 to 75.5 cm. This serves to remove some additional moisture from the product, this being accompanied by cooling of the product through evaporation. If normal solid oil is used, evaporative cooling is preferably used to reduce the temperature of the product below the melting point of the oil, thereby solidifying the remaining oil before breaking the vacuum. The use of a high vacuum at the end of the operation has another desirable effect in that it tends to expand the cell or tissue structure just before cooling has progressed so far that processing or hardening of the tissue and solidification of the oil occur, thereby creating a optimal volume is maintained. Pipeline 82 is provided for the introduction of cooling water at the end of the operation, as described above.

As an alternative to the working method just described, this can be Valve 74 is in the open position during the workflow, in this case the housing 73 in fact forms part of the treatment tank. The valve 74 may at the end of the workflow after practically all or most of the free oil of the free oil has been removed must be closed. The smaller, isolated one Housing 73 facilitates the application of a higher vacuum.

After completing the workflow as described above has been brought, tube 78 is opened to de-humidified air or a admitting another gas at atmospheric pressure to the housing 73, whereupon the housing detached and the product removed. Instead of letting in atmospheric air, it is desirable to use cool gas that has been freed of moisture, thereby not re-entering any noticeable amount of moisture from the gas into the product is introduced. Instead of using air, inert, anhydrous gases, such as B. nitrogen, can be used, which serves to fill the pores with an inert To fill gas, thereby excluding oxygen. Likewise is the use of sterile air or another gas is desirable, especially in cases in which the avoidance of any pollution by introducing into the air borne microorganisms (e.g. bacteria or mold) is desired. Active Gases such as B. ethylene oxide, can be used to remove such microorganisms destroy or inhibit. Applying a treatment gas to the vacuum draining is particularly effective because the porous product has a has minimal amount of absorbed and trapped gases and the gas in the course the evacuation of the vacuum is effective into the pores or cells of the product to penetrate.

In Fig. 4, the blocking screen 64 can be moved vertically as in FIG. 3. Another arrangement is shown in FIG. 5 shown. In this case, a rotary screen 81 is provided in the container 61 and attached in a fixed elevation above the valve 74. In the position shown with dashed lines, the screen allows the material to move freely. However, when rotated 90 ° to the position shown in solid lines, it acts as a holed lock. During the initial phase of the operation, the sieve 81 is in the position indicated by the dashed lines. At the end of this initial phase, the foam collapses and the dried material is buoyant. Some oil is withdrawn through tube 72, lowering the oil level and floating material below screen 81. Sieve 81 is now rotated to the position shown in solid lines, whereupon hot oil is introduced into the container in order to bring the oil level above the sieve. The operation then continues with the particles of material being held beneath the surface of the oil by the sieve.

The initial phase of the process is influenced by the level of vacuum maintained, particularly the rate at which steam is evolved and the volume of the mixed phase medium. For example, with one with the one shown in FIG. 4 comparable device, which has a container 122 cm in diameter and about 12.20 m high, the initial charge of oil results in a liquid level of about 1.22 m, calculated from the bottom of the container. When using fresh celery with a dry matter content of about 10%, which has been cut into pieces of 9.5 mm thickness and frozen at -17.8 ° C, about 136 kg of load can be converted into about 1360 kg of oil at 204 ° C during one A period of about 7 seconds should be introduced. Under these conditions, while maintaining an initial partial vacuum of 61.0 cm of mercury, a mixture of vapor-oil medium is created immediately after the feed is introduced which is about three times the volume of the liquid. However, at a partial vacuum of 63.5 cm of mercury, the volume of the medium is approximately four times the volume of the oil feed. In the same way, with partial vacuum values of 66.0, 68.6 and 71.1 cm of mercury, the corresponding volumes are five times, six to seven or eight to nine times the original volume. At 73.7 cm, the volume of the medium is on the order of ten times or more the initial volume. From these lines it can be seen that the partial vacuum maintained during the initial phase of evaporation, during which time most of the moisture is removed, can be adjusted to desired conditions and in accordance with the particular device used, whereby the desired rapid evaporation takes place, but that Mixed phase medium does not have sufficient volume to result in significant foam transfer into the condensation and evacuation device. Generally, based on the observations, an initial partial vacuum on the order of 63.5 to 71.1 cm of mercury can be applied at the time the feed is introduced into the oil, followed by a decrease in the partial vacuum to about 55.9 to 63.5 cm but returning to about 71.1 cm or more after the first few minutes of the workflow.

In general, both initial oil temperature and value are applied Vacuum factors that affect the rate of first evaporation. This allows for higher evaporation rates than those listed above can be obtained by maintaining a relatively high vacuum at high temperatures (e.g. above 73.7 cm). For example, speeds which remove most of the moisture over time effect in the range of 15 to 120 seconds.

Different packaging methods can be used for storage and distribution be applied. In general, customary packaging methods can be used as they are used for common dried foods, including packing in cardboard boxes, plastic and foil bags, metal cans, Glass container or the like. If exposure to atmosphere is too undesirable In some cases, the packaging can be hermetically (airtight) closed containers, for example in closed tin cans or glass vessels, be carried out. Packaging with glass treatment can be made to prevent oxidation to prevent. So at the end of the drying process, the vacuum with anhydrous, sterile nitrogen and then the products in the same Gas packed. If sterilization is important in the packaging, antiseptic can be used Egg preservation in cans or packaging can be used, with the product in placed in sterile cans in a sterile state and the cans under sterile conditions be locked.

If the products have a significant moisture content (e.g. 10 to 30% on an oil-free dry matter basis), they can be frozen in State or be kept refrigerated with or without packaging. If so desired i can use legally permitted preservatives, such as B. Mold inhibitors, used to handle such products. As stated above, leads the drying of most moist foods by the more general common ones Process for a significant shrinkage in volume. According to the procedure according to of the invention, as applied to most fabrics, owns the final product a volume and a shape which are similar or not very different from that Are the starting material. That gets in part from the puffing effect of the steam attributed to the initial phase of rapid evaporation, which is the overall structure which leaves particles generally unchanged. Also, this will affect the solidification an outer porous layer long before the operation is finished, returned, as described in more detail below. This will continue to apply to centrifugation Recirculated under vacuum and cooling by evaporation, thereby reducing when draining the vacuum does not cause the product to collapse due to externally applied pressure is brought. In other words, the pores are at the time when the vacuum is broken off, opened and the particles relatively firm or stiff. Therefore can Air or some other gas can flow into the pores without the particles collapsing bring to. If the end product is subjected to a higher vacuum and that This cools the product and solidifies the oil before releasing the vacuum is, this contributes in the same way to the production of a product, which regarding Volume and shape are comparable to the original material.

In certain cases, sirre can use special prep processing increase the volume of the end product. So can the material heated to a temperature in the range of 38 to 60 ° C immediately before freezing and then the drying trays containing the warm particles on shelves be arranged by encircling. Cooling medium are quenched. The those The atmosphere surrounding drying sheets is reduced to a partial vacuum of the order of magnitude evacuated from 73.7 cm of mercury. The wet particles are thereby immediate stretched before freezing and then frozen in the stretched state. Such frozen ones and expanded particles can be stored and followed the process in the same way, as described above. It was found that this extension at the time of freezing, the volume of the dried end product is significantly increased. The interior of the particles of such a final product tends to have larger air pockets or having voids which accelerate rewetting tend on contact with water. The products treated in this way, for example fresh peas, have inner kernels, which against the inner surfaces of the Skin are pressed, with a relatively large air cavity between two cores remains. Dried blueberries made in this way have something similar Properties. In general, both those treated in this way show greens Peas as well as the blueberries have a smooth external appearance and tend to be more attractive than the products made without prior vacuum expansion became. Certain materials seem to be suitable for this treatment, like z. B. those with an outer skin or a skin-like surface with a significant Amount of trapped air. In particular, blueberries, peas, apples, pre-dried Apple and peach schnitzel, fresh or partially dried grains, such as B. corn, and meat can be mentioned. Meat types can be made according to this procedure treated to increase the porosity of the finished product, this being the Re-moistening with water makes it easier.

As mentioned above, the preparatory processing of the raw material modify its natural state considerably. For example, can cherries Treated according to customary methods to those commercially available as maraschino cherries known products. Such cherries were in their processing subjected to salt water hardening and boiling, as well as the addition of sugar syrup been. The above-mentioned common glazing treatment is similar Wise in cooking with the introduction of additional sugar. The moisture content of materials processed in this way is considerably lower than the moisture content of fresh raw material. Maraschino cherries have z. B. a moisture content in the range of about 6004, and glazed cherries have a moisture content of about 201 / o. These processed materials can be processed according to the method according to the invention treated to produce products with a moisture content between 2 and 20%, the higher moisture content in such products due to the sugar content is permissible. Such products form products when rewetting are comparable to the original maraschino or glazed products.

The preparatory processing of materials such as cereal grains, Chickpeas and lentils, can rewet the dried material and include the removal of the skins, whereupon the moist kernels are frozen out. Likewise, dried meat can be re-moistened, frozen and then re-moistened processed according to the procedure. Before re-moistening can Grain grains are subjected to various grinding operations, such as. B. to Removal of peel, bran and germ parts, making a slightly moistened again Product is obtained. Soluble components can be in the rehydrating fluid be introduced, such as B. Flavor-imparting substances or spices, vegetable or animal slimes or dg1.

Soaking in vinegar was mentioned above as a pretreatment. The method according to the invention can be applied, for example, to pickled; Cucumbers, tomatoes, olives, onions, peppers or the like. Can be used.

As before with reference to meat, poultry and seafood mentioned, cooking, with or without seasoning, can be used as a pretreatment. Legally permissible, customary preservation methods can also be used become, such as B. Treatment by salt water, smoking, curing or the like.

With most fruits and vegetables it is generally desirable to use fresh raw materials, thus creating the finished product completely similar to the original fresh raw material when re-moistened is.

During the preliminary drying, certain fruits (e.g. peaches) or vegetables after cutting into pieces or slices of the appropriate type Size the common drying process, for example by contact with warm air at temperatures ranging from 54 to 71 ° C, whereby the moisture contained therein is reduced to a significant extent, for example to a moisture content of 15 to 60%. Common types of drying or drying shaft ovens can be used. Instead of Use of air dryers can result in sun drying by exposure to the sun Drying trays are applied. In some cases this drying can be applied before the product is cut into the desired shapes. Such materials can be frozen directly and subjected to the method according to the invention, however, they are preferably partially re-moistened before freezing. Partial rewetting leads to products with a greater porosity and a lower weight per unit of volume. Fruits treated this way Are dates, figs, raisins, peaches, pears and apricots. Regarding the products that are partially concentrated or preserved with sugar, can be further on various candied fruits, including pineapple, candied sweet potatoes and yams can be referred to. Other pre-dried products, to which the method according to the invention is applied after rewetting can be are chestnuts and dried mushrooms.

As for the more common dried fruits, such as tree ripened Dates, dried figs, prunes and oven-dried apples, which up Can contain up to 20% moisture, these products will be after storage cleaned, rewetted, doubling the moisture content and then frozen. Then they will follow the method according to the invention exposed. The products obtained after this rewetting have an enlarged Volume compared to the dried starting material before moistening, and because of the restoration of the previously shrunk tissue structure. she are also porous, relatively soft and easily resume when they come into contact with water Water on. The drying operation can be canceled to produce products with a To remove moisture content which is that of conventional, dried Fruit is comparable, such as. B. 20%.

Many formulated products can be made according to the method according to the invention to be dried. Examples of this are products made from dough, with or without a fermentation or leavening agent, such as. B. baking powder or yeast, and with or without prior partial baking to activate the propellant. Further Examples include puddings, products known as snacks, and products the one filler or a similar mass of a food and one enveloping Contain dough layer, such as. B. perforated raviolls with a meat-like filling. Another example is a product with a fruity filling, such as B. pieces of fruit, fruit jam or fruit pests, which partially or completely are enclosed in a batter.

It is common in the dried fruit industry, on certain dried ones To use sulphurisation in fruit to extend its lifespan and in order to general to support the conservation. In accordance with the procedure According to the invention, if sulphurization is desired, the dried end product can be placed in a sulphurisation chamber, where it is exposed to the usual sulphurous gases will. The gas should be at a temperature just above the melting point of the. Oil or the product is heated to this temperature in some other way. After removal from the sulfur chamber, the product is allowed to cool, with the surface retains the applied sulfur. Another procedure exists therein, the cleaned and cut raw material in a solution of sodium sulfite immerse, whereupon the material is frozen. After doing it according to the procedure of the invention was dried, the finished product had residual sulfur depending on the particular raw material treated and the strength the treatment solution.

The method can advantageously be used to provide a new technique for making glazed cherries and similar fruit products with an additional sugar content. For example, drained saltwater cherries can be cooked in sugar syrup, ie a syrup that is gradually enriched to 25% and mixed with color and flavor. After the excess syrup has run off, these cherries are frozen and processed according to the method according to the invention, removing them from the hot oil with a moisture content of about 20%. According to this method, a product of high quality can be produced which has retained the original color, taste and cell structure, and this is achieved through treatment steps which are simple and time-saving compared to conventional methods.

With regard to the application of the. Method according to the invention Cereal grains can be suntanned in the field by cleaning and remoistening are prepared, after which it is frozen and the frozen product is then subjected to the procedure. This can be done before rewetting Grain grinding operations are subjected to, for example, for removal of shell and bran parts and, if desired, for the removal of germs to serve. The product obtained consists of dried grains with a moisture content on the order of 2 to 3% and having a volume and shape which are comparable to the original granules. It's relatively soft and crushes and quickly absorbs water again on contact with water. After re-moistening the shape of the original granules is restored. By-products that are Resulting from the grinding, for example wheat germ, can in the same way be dried according to the method according to the invention. It was assumed above that to keep cooking and browning to a minimum during the drying process are. However, in some cases, especially with farinaceous materials, such as B. flour dough, it may be desirable to have a predetermined degree of baking or Browning of the products should be carried out at the same time as drying. This can be done by the use of higher oil temperatures after the first initial evaporation phase, for example, with temperatures in the range of 104 to 149 ° C, can be achieved.

In some cases - the product obtained (for example in the case of corn) suitable for eating without further treatment by the consumer. It can also Products such as garbanza beans, lentils, chestnuts or grains after drying exposed to browning and ripening according to the invention in order to obtain a good edible, win a nut-like product.

In most cases the dried product will be according to the invention processed by the consumer before it is eaten. For example You can put dried vegetables, such as green peas, in warm water for recovery are immersed in water, whereupon they are subjected to ordinary boiling will. In a simpler procedure, the housewife can have a measured amount of dried Put the material in the saucepan and add a predetermined amount of water put a lid on the pot and put it in a warm oven. When the water is heated to the boiling point, it will rewet the Vegetables and performs the necessary cooking. Following this procedure requires making ready-to-eat vegetables no more than about 5 to 10 minutes. Instead of to require the houseguests to put a measured amount of dried material in one To give a cooking vessel, the dried material can be placed in a metal foil cooking kettle can be bought, whereby the housewife only a measured amount of water this packaging needs to be added and this is then placed in a hot oven for a predetermined period of time represents.

In some cases, the dried product can be used in so-called baking premixes instead of being sold as such. For example, can blueberries dried by the method according to the invention in a pancake dry premix be given, with the blueberries, if a thinly whipped pancake batter formed with water or milk, tend to absorb water and moisten finished while the pancakes are being baked. With regard to such premixes there is a desirable feature of the vegetable and fruit products according to the invention in that they suspend in the premix and in the baked batter and that they swim in light, thin, whipped pancake-type doughs.

That after. Process according to the invention possesses product obtained new properties which it compared to the previous methods Award products. With specific reference to products which, through application of centrifugation under continued partial vacuum at the end of the drying operation has been manufactured. have all products made according to the invention excellent quality with regard to such characteristics as Color, taste, nutritional value, shape and size, fragility, lifespan, speed and extent of rewetting.

Color retention is good to excellent, inclusive maintaining the fresh green and red color of fruits and vegetables, as shown by actual color analysis. Mushrooms are an exception to that they take on the brown color of cooked mushrooms in the light, and probably do so due to chemical changes in color components, which are likely caused by enzymatic activity and not by surface browning or Color absorption can be caused by the treatment oil. There is a slight depression the colors on all products, but not to a sufficient extent, to significantly modify the original color shade. Some substances that one have natural white color, such as B. thin potato schnitzel are negligible to the point of assuming a darkened white or light cream color darkened. Such discoloration can occur through special pretreatments be brought to a minimum, such as B. by dipping the material before freezing in sulfite solutions or bleach.

The taste is excellent in all products. It will no burnt or bad taste developed. The one resulting from the proceedings Residual oil content has no significant concealing or modifying effect the taste of the re-moistened product, if not desired flavor components deliverable in the methods described above. The Irish to another oil or the replacement with another oil in place of the one in the initial phase The oil used can serve to reduce the unwanted absorption of taste or darkened Reduce or eliminate particles from the initial oil to a minimum.

The nutritional value of the products is practically not affected, whereby particular reference is made to carbohydrates, proteins and vitamins. Starch granules, as found in certain vegetables, such as B. Potatoes, turnips, parsnips, white beets and sweet potatoes are completely gelatinized. This extends the Suitability for consumer use and does not affect the nutritional value. Those present Proteins can be denatured somewhat, but without disrupting rewetting or significantly affect taste or nutritional value. Substances with a high protein content, such as meat, poultry and seafood, are generally pretreated cooked, and then there is no further denaturation during processing instead of.

In terms of shape, the dried particles are the finished products similar to the particles of the raw materials. In other words, the original physical shape is largely retained in the finished product. The volume shrinkage is not excessive and can be done by the specific procedures described, including the application of vacuum during freezing and / or the application of a high vacuum at the end of the workflow, should be kept to a minimum. All products according to the invention are relatively stable in their resistance to mechanical abrasion or incorrect handling. So they can without developing excess fine material to be handled or packaged. This is in contrast to certain dried products made by freeze drying processes were, such as B. cooked meat, poultry and seafood that are very fragile are. The lack of brittleness is due to the softening effect of the process according to the invention originating oil, which is mainly in the form of tiny Bead is distributed in the cellular spaces and on the retention the natural bond between cells that appears to occur in the freeze-drying process lost or impaired.

As shown by accelerated oxidation tests, the service life is as good or in some cases better than products made by freeze-drying processes in terms of the ability of the material to damage to resist by oxidation when exposed to the atmosphere. The out The oil content derived from the process tends to precede substances with a low fat content to protect against oxidation and the absorption of atmospheric moisture inhibit.

The products according to the invention are speed-oriented and extent of rewetting excellent. This is an important indicator as it is intended to re-moisten the products before they are used. try showed that when the products according to the invention were immersed in water at 60 ° C rapid water absorption takes place, with the formation of substances which practically the same as the starting materials in terms of shape, size, appearance and structure are. The residual oil content does not interfere with this absorption, which is attributed to the fact is that the residual oil resulting from the process is mainly in the form of tiny Individual dimensions in contrast to plates, films or other dimensions of greater significance Sizes which tend to block the penetration and absorption of moisture, is distributed. The tiny individual masses are distributed arbitrarily, whereby they mainly in the intercellular spaces and more in the outer than the inner areas are present. Good rewet properties are also based on the fact attributed to the fact that the product is porous, making it easily penetrable for water is. The tissue and cell structure is easily wettable and absorbs water and has the ability to return to a form and character, which are comparable to those of the original starting material.

The amount of oil that comes from the process and is retained in the product will vary in the manner in which the process is carried out with the Character of the oil used and the special material that is treated. Some retain more oil than others under the same treatment conditions. This is due to the differences in chemical and physical properties, including the differences in the presentation of the tissue or cell structure, returned. Substances that normally have a significant amount of oil or fat, for example cooked meat, lose only a small amount their natural fat and hold some of that used in drying Oil back.

Experiments showed that a wide variety of fresh vegetables, which were dehydrated according to the method according to the invention, an oil content each Have retained unit volume in the range of about 100 to 200 mg / ccm. fruit lead to products with a little more fat content per unit volume, for example from 100 to 235 mg / cc. Cooked. Meat or poultry yields products within the Range from about 100 to 150 mg / cc. Seafood products such as shrimp and fish, result in products within the range of about 150 to 225 mg / cc. Spice up, like mushrooms, give products in the 140 to 160 mg / cc range.

The evaporation during the operation, including the rapid Evaporation during the first few minutes of the workflow takes place in a in such a way that a porous product remains, which becomes easy and practically complete rewetting is appropriate to a particle with To form hallmarks including shape and size that are similar to the starting material are. The outer regions of each particle are porous in shape and up to one Extent dried, which tends to give rigidity and strength before the inner parts have a comparable moisture content and a comparable one Achieve stiffness. In this way, a porous outer area or a Layer formed long before the end of the operation, which with shape and size of the starting particle and which have sufficient rigidity and strength possesses to withstand significant overall inward shrinkage, which in other ways practically take place with complete collapse of the tissue could. Although the inner tissue can be spongy in character, such as B. in juicy vegetables, the outer layer of the stronger or stiffer one predominates cellular tissue in maintaining shape, size and porosity. That inner tissues can, especially if they are juicy and spongy, during the drying process something can be broken up, but it essentially retains the same spatial dimension Arrangement and storage within the outer rigid areas. As if by microscopic Examination has shown, the inner tissue can take the form of veins or strands bundle together, which are separated from each other by empty spaces, without the outer porous structure is caused to collapse inward.

The invention is explained in more detail below with reference to the examples: Example 1 The starting material consisted of fresh, ripe blueberries. They were prepared by washing, after which they were specially frozen and stored at a temperature of about -15.0 ° C. The device was that in FIG. 3 similar. A quantity of hydrogenated cottonseed oil having a melting point of about 42 ° C was added to the container 40 and heated to a temperature of about 127 ° C. A measured quantity of frozen berries in the ratio of 2.27 kg of berries to 45.4 kg of oil was placed in the raised drum of the container and while still held above the oil, a vacuum corresponding to 71.1 cm of mercury was drawn. After a period of about one minute during which the berries were deaerated, the drum was lowered to the bottom of the container. Immediately a foam-like medium was formed, which consisted of water vapor and oil and took up several times the volume of the original oil mass. The initial phase of the operation extended over a period of about 4 minutes following the introduction of the blueberries, during which time the oil cooled to a temperature of about 71 ° C. Here, too, there was lively movement with rapid development of water vapor. The partial vacuum dropped from an initial 71.1 cm of mercury to about 63.5 cm and then rose to about 71.1 cm towards the end of the first 5 minutes. Some heat was added to the container by means of an enveloping steam jacket, which increased the temperature from a low temperature to about 71 ° C at the end of the first 4 minute period to about 96 ° C and then maintained it at about 90 ° C. Approximately 10 minutes after the operation began, screen 42 was lowered to keep the particles immersed in the oil for the remainder of the operation.

After a total drying period of about 18 minutes, the Drum 42 is raised to the top of the container where the free oil drains allowed by the product while the application of vacuum was continued. The vacuum was then broken and the product removed from the container.

The product obtained from the above example had a residual oil content of about 601 / o and a moisture content of about 2% (total). Although that Product did not have certain desirable properties of the products, which obtained by centrifugation under vacuum at the end of the drying process It was in several ways the dried blueberries which were common after Drying methods obtained are superior. Most importantly, the product had about same shape and size as the original fresh berries and color and Flavors were excellent.

Example 2 The same procedure as in Example 1 was followed with the exception that liquid sesame oil was normally used. After Removal of the product from the container allowed it to cool in about 5 minutes allowed to stand, whereupon the berries are placed in a drum-type centrifuge where the product was centrifuged to remove additional residual oil. A warm air flow at a temperature of about 60 ° C was fed into the centrifuge bowl introduced to aid oil removal. The end product was similar to that in the example 1 obtained product and had a residual oil content of about 50%.

In general, this product was about the same as that of Example 1, with the exception of the reduced oil content. Example 3 It was the same starting material and procedure were used as in Example 2. However with regard to freezing, the berries were first warmed to about 49 ° C. and then a partial vacuum of 71.1 cm of mercury immediately before and during freezing exposed.

The finished product was remarkably puffed up or stretched out. Example 4 Blueberries were prepared as frozen in Example 1 and stored at -28.9 ° C. Laboratory equipment similar to that of FIG. 3, with drum 42 being 11 inches in diameter. The oil consisted of hydrogenated vegetable cooking fat, which had a melting point of about 42 ° C and was at an initial temperature of 182 ° C. Approximately 0.454 kg of frozen berries were introduced for every 4.45 kg of oil. The procedure used to the end of the drying operation was essentially the same as in Example 1. The drying period was 20 minutes and the vacuum applied was 71.1 to 73.7 cm of mercury. After the drum 42 was raised and the oil drained, the drum was rotated at 1150 rpm for about 4 to 5 minutes while continued application of the partial vacuum to effect further removal of free oil. The vacuum was then broken and the product removed.

The product obtained was different from the products obtained in Examples 1 and 2, in particular because of its reduced oil content. The moisture content was 1.73% (total) and the residual oil content was about 39.07%. The density was 0.5 g / ccm and the residual oil content, expressed in weight per unit volume, was about 200 mg / ccm. The product quickly absorbed water again when immersed in water at 60 ° C. Thus, in one minute the weight gain due to water absorption was 19%, in 10 minutes 360/0, in 30 minutes 73% and in 60 minutes 951%. Example 5 The starting product was MLnneSOta-Red potatoes. The potatoes .. were peeled, cut into slices and diced into pieces with the dimensions 1.9 - 1.8 - 0.31 cm. They were frozen and stored at -29 ° C. The laboratory apparatus was similar to that in FIG. 3, the drum 42 being 27.94 cm in diameter. The oil was hydrogenated vegetable cooking fat, as in Example 4, with an initial temperature of 182 ° C. Approximately 0.454 kg of frozen potatoes were added for every 4.54 kg of oil. The drying period was 15 minutes and the vacuum applied was 71.1 to 73.7 cm of mercury. After the drum 142 was raised and the oil drained, the drum was rotated at 1150 rpm for about 4 to 5 minutes with continued application of the partial vacuum. The vacuum was then broken and the product removed.

The product obtained from the previous example was good Quality with a moisture content of 2.34% (total). The remaining fat content was 20.55, the density was 0.50 g / ccm, and the fat content per unit volume was 103 mg / cc. On contact with water, the product easily absorbed water again. So scam in contact with water of 60 ° C, the increase in weight due to water absorption 89% in one minute, 142% in 10 minutes and 229% in 30 minutes. Example 6 As a starting material fresh white rose potatoes were used. They have been peeled and cut into narrow ones Shredded strips, the chips being about 3.17 mm thick. The schnitzel were immersed in a sodium bisulfite solution for a period of one minute a content of 28.35 g of sodium bisulfite per 2.27 kg of water. Then were the potato schnitzel is particularly frozen and stored at -13.9 ° C. The used Apparatus was similar to that in FIG. 4 shown. The container 61 was hydrogenated with 1360 kg Vegetable cooking fat charged with a melting point of about 42 ° C, which is an initial temperature of 160 ° C. 90.7 kg of the frozen, chopped potatoes were added to the container 66 fed and the feed a partial vacuum (7l, 1 cm) together with the Inside of the container 61 subjected. It took about 7 seconds to complete the Feed the load to the container 61. When the first part of the charge comes into contact was brought with the oil, a water vapor-oil medium or formed immediately Foam which extended upwardly into container 61 and through which the remaining part of the feed was introduced. Most of the foam sank after the first 3 minutes of the process, and shortly thereafter the Sieve 64 lowered to keep the product immersed in the oil. The total time of the operation was 15 minutes plus an additional 3 minutes, which for the Pumping out the oil at the end of the operation were required. The applied Vacuum was 66.0 cm of mercury at the beginning, but fell during the initial phase dropped to about 63.5 cm and then rose again to 71.1 cm at the end of the first 5-minute period. The oil temperature dropped to around 71 ° C in the first 3 minutes, whereupon heat was applied to raise the oil temperature to about 93 ° C, wherein it was held for the remainder of the operation. The product was in the centrifuge drum 75 deposited (91.4 cm in diameter) by simultaneously drawing free oil from the container and the housing 73 was pumped out, and then the centrifuge drum rotated at 300 rpm while the vacuum was at about 71.1 cm of mercury was maintained. Then the rotation of the drum was stopped, the housing 73 detached from the container and the product removed.

The product obtained in the above example was excellent Quality with a moisture content of around 1.2% (overall). Color and taste were excellent and the product was easily re-moistened on contact with water.

Example 7 The starting material was the same as in Example 5. Die Potatoes were cut into cutlets of about 3.17mm thick and then immersed in sodium bisulfite solution. Then the schnitzel individually frozen and stored at around -12.8 ° C. Same device and the same general procedures as in Example 5 were followed. However, the feed ratio contributed 118 kg of frozen potatoes to 1360 kg of oil, which was heated to 166 ° C. While The oil temperature dropped to 71 ° C. in the first 21 / z minutes of the operation. It heat was applied to bring the temperature back to about 93 ° C. The temperature was held essentially at this level, being 96 ° C at the end of the run fraud. The total duration of the drying process was 20 minutes plus more 21 / z minutes for pumping out the oil. The partial vacuum applied at the beginning was 66.0 cm of mercury, which dropped to 63.5 cm in the first few minutes and then rose again to 69.8 cm, where it was for the remainder of the operation remained. The sieve 64 was below the oil line (oil level) about 12 minutes after the start of the work flow. After pumping out the oil, the product was about 3 Centrifuged for minutes after which the vacuum was released.

The product obtained in the previous example was practically the same like the product obtained in Example 4, with the difference that this material was in the form of schnitzel. The moisture content was about 1.4% (total). Example 8 Fresh carrots were used as the starting material. After washing the carrots were sliced sideways into cutlets about 3.17 mm thick. Afterward they were frozen and stored at -28.9 ° C. The laboratory equipment used was similar to that in FIG. 3 shown. The feed ratio used. fraud 0.454 kg of frozen material to 4.54 g of hydrogenated vegetable cooking fat, this being. Oil had an initial temperature of 182 ° C. The general procedure used using the device was the same as in Example 3. After the introduction of the frozen feed, the oil temperature dropped rapidly, with a minimum temperature of about 96 ° C was reached. The partial vacuum was at about 71.1 to 73.7 cm Mercury column held. The total duration of the drying operation was 30 minutes after which the product was removed from the oil. After a short period of time the product was centrifuged under vacuum as in Example 4 and then the vacuum drained.

The product obtained by the above example was excellent Quality compared to the dried carrots, which by the more common ones Procedures were obtained. It was excellent in terms of retention Color and taste. It had a fat content of 51.8% and, in terms of fat content per unit volume, it contained 178 mg / ccm. Its moisture content was 3.40% and its density 0.35 g / ccm. It was slightly re-moistened on contact with water at 60 ° C, producing a reconstituted product that is practically the same as the home carrot was. So was the weight gain due to water absorption 95% in one minute, 1501 / o in 10 minutes, 189% in 30 minutes and 60 minutes 252%.

Example 9 Fresh carrots as in Example were used as the starting material 7 used. The apparatus used was practically the same as that in F i G. 4 shown. The frozen schnitzels were stored at -13.9 ° C. The loading was 102 kg of frozen carrots per 1360 kg of hydrogenated vegetable oil, which is based on 163 ° C was heated. During the first initial phase of the operation, the oil temperature fell to 71 ° C. Heat was applied to bring the temperature back to around 93 ° C, Where. it was held during the rest of the operation. The entire drying process Required 14 minutes plus, about 3 minutes for oil pumping. The sieve 64 was lowered to the product below the surface of the oil during the last Keep your corset pressed for 5 minutes of the 14-minute work step. The partial vacuum At the beginning was 69.8 cm of mercury, immediately dropped to about 63.5 cm and then returned to about 69.8 cm of mercury after the first 5 minutes and remained practically at this value for the remainder of the work continuation. The free oil was pumped off and centrifuged under vacuum for about 3 minutes (91.4 cm drum rotating at 300 rpm) and the vacuum was released.

The product obtained in the previous example was practically the same like the product obtained in example 6. The moisture content was about 2.10% (all in all). Due to the shorter working cycle, the fat content was considered to be lower as in example 6, the density is lower and likewise the ratio of fat to Unit of volume added somewhat reduced. Example 10 As a starting material fresh celery bulbs used. After washing, the tubers were in pieces from 1.9 to. 2.2 cm length cut. They were then frozen and stored at -28.9 ° C stored. The laboratory equipment used was similar to that in FIG. 3 shown and was operated in the same way as described in Example 3. The initial oil temperature was 182 ° C and the charge ratio was such that 0.454 kg of frozen material were used on each 4.54 kg of oil. The applied partial vacuum was at about 71.1 to 73.7 cm of mercury was maintained throughout the workflow. the The total duration of the drying process was 15 minutes. During the initial phase During the operation, the temperature dropped to 93 ° C, where it was for the remainder of the operation was held. The product was centrifuged under vacuum as in Example 4, before the vacuum was released.

The product obtained from the above example was excellent Quality. The moisture content was 2.2% (total) and the fat content was 21.92%. The density 0.36 g / ccm and the fat content per volume unit 187 mg / ccm. The product was slightly and completely re-moistened on contact with water at 60 ° C. So was the weight gain due to water absorption in one minute 15407o, in 1.0 minutes 245%, in 30 minutes 290% and in 60 minutes 350%. After remoistening, the product was practically the same shape, size and shape general appearance like the fresh material.

Example 11 Fresh celery bulbs essentially as in Example 10 were used as the starting material. After washing, these were bleached in a pressure vessel by contacting them with steam under a pressure of 0.70 kg / ccm 2 at a temperature of about 1.16 ° C for a period of 3 minutes. They were then cooled to room temperature, frozen and stored at -1.2.8 ° C. The device used was similar to that in FIG. 4 shown. The charge ratio was 134 kg of frozen material to 1360 kg of hydrogenated vegetable oil at a temperature of 166 ° C. At the time the product was first introduced into the oil, the partial vacuum was 67.3 cm of mercury. The oil temperature dropped to 60 ° C in about 3½ minutes. During the same time, the vacuum dropped to about 64.75 cm of mercury in about one minute and then increased to about 71.1 cm of mercury at the end of the first 3 minute period, remaining there for the remainder of the operation. The oil temperature was kept at about 90 ° C after the initial phase of the operation. The total drying time was 19 minutes plus about 3 minutes for pumping out the free oil. After pumping out the oil, the material was centrifuged (91.4 cm drum at 300 rpm) under vacuum for 3 minutes and the vacuum was then removed. The product was then air-cooled and packaged.

The product obtained in Example 11 above was of approximately the same quality as the product obtained in Example 10. It was softer after re-moistening due to the bleaching ice. Example 12 Green beans were used as the starting material. They were prepared by washing and cutting into slices about 3.17 mm thick and a length corresponding to the length of the bean (6.55 to 7.62 cm). They were then frozen and stored at about -17.8 ° C. The device used; was similar to that in FIG. 4 shown. The feed ratio was approximately 153.6 kg of frozen material to 1410 kg of hydrogenated vegetable oil with an initial temperature of 171 ° C. After the completion of the introduction of the frozen material, the applied partial vacuum was 67.3 cm of mercury. Over a period of 4 minutes, the oil temperature fell to 77 ° C. Heat was applied to bring the oil temperature back to 88 ° C., and this temperature was then maintained for the remainder of the operation. The total drying time was 12 minutes plus 3 minutes for pumping out free oil. That. Sieve 64 was lowered into position about 5 minutes before the end of the cycle. The partial vacuum applied was initially about 67.3 cm, whereupon it immediately dropped to about 61.0 cm for about 2 minutes and then returned to 71.1 cm, where it was held for the remainder of the operation. After the oil had been pumped out, centrifugation was used (91.4 cm drum at 300 rpm) as in Example 9.

The product obtained in the previous example was excellent Quality with good color and flavor retention. Its moisture content was 1.6%. It was slightly re-moistened on contact with warm water.

Example 13 As a starting material, fresh mushrooms became a common one Kind of like in the VStA. are sold in commerce. After washing the head and stem were separated and the larger pieces split. They were subsequently frozen and stored at -28.9 ° C. The device used was that in the example 3 listed laboratory device similar. The feed ratio was 0.454 kg of frozen material for each 4.454 kg of hydrogenated vegetable cooking fat a temperature of 182 ° C. The partial vacuum applied was about 71.1 bis 73.7 cm of mercury. The initial oil temperature quickly fell to around 93 ° C, where it was held during the rest of the operation. The entire drying process took about 20 minutes. The material was then lifted out of the oil and Centrifuged as in Example 4 to remove residual free oil. Then became the partial vacuum released and the product removed.

The product obtained in the previous example was excellent Quality. It had a moisture content of 0.6%, a density of 0.34 g / ccm and a fat content per unit volume of 148 mg / ccm. It was in contact with Water slightly re-moistened at 60 ° C. So the weight gain was due of water absorption 80% in one minute, 130% in 10 minutes and 30 minutes 190 0/0. It was brown in color in contrast to the relatively white color of the Starting material, which, as mentioned above, is attributed to chemical changes will. In general the quality was excellent.

Example 14 The starting material was canned technically Water chestnuts are used in the form of shavings, each about 3.17 mm thick. After draining this material, it was frozen and stored at -11.7 ° C. The apparatus used was essentially that shown in FIG. 4 shown. 101.5 kg frozen material was placed in 1410 kg hydrogenated vegetable oil at 166 ° C. The oil temperature immediately dropped from 166 ° C to about 82 ° C and was increased by feed increased by heat to about 93 to 94.8 ° C and at this temperature during the the rest of the operation. The total duration of the drying process was 15 minutes plus 3 minutes for pumping out the oil. The initial partial vacuum was about 67.3 cm, dropped immediately afterwards to about 60.3 cm and then returned back to about 69.8 cm in the first 2 minutes, where it was during the remainder of the operation was held. Some oil was continuously removed by removing the bottom and Reintroduction in the case of a mirror, just below the swimming height of the product. circulated. Sieve 64 was lowered during the last 4 minutes. After removing the. Free The product was centrifuged under vacuum for 4 minutes (91.4 cm drum at 300 rpm) before the vacuum was released.

The product obtained was of good quality and useful for many purposes suitable to be used for the water chestnuts. The moisture content was about 1.6% (total).

Example 15 Fresh lean beef was used as the starting material used. It was cut into 2.54 cm cubes and at steam pressure from 1.05 kg / cm? - cooked for 20 minutes. The cooked material was cut into cubes cut about 1.27 cm thick or less. After the expiry of the Cooking ice extracted juices, the cooked beef was frozen. and at about -28.9 ° C. The device used was similar to that given in Example 3. The feed ratio was 0.454 kg of frozen beef for every 4.54 kg of hydrogenated vegetable cooking fat at an initial temperature of 182 ° C. The applied Partial vacuum was at around 71.1 to. 73.7 cm of mercury held. Direct after the introduction of frozen beef loading, the oil temperature dropped quickly to about 93 ° C, where it remained during the remainder of the operation. the Total drying time was 14 minutes. Then the product removed from the oil and, after draining, centrifuged under the same vacuum (as in example 4) to remove the remaining free oil. Then the vacuum drained.

The product obtained from the above example was excellent Quality. It had a total fat content of about 14.5%, of which about 90% was from the Treatment oil originated. The moisture content was 0.66% (total). The concentration was 0.84 g / ccm and the fat content per unit volume was 122 mg / ccm. Color and Flavor retention was excellent. The material was in contact with Water slightly re-moistened at 60 ° C. So the weight gain was in one Minute 431 / o, in 10 minutes 72%, in 30 minutes 79% and in 60 minutes 82%.

Example 16 As. Boiled chicken was used as the starting material. It was made by boiling, boning, removing skin and dividing it into cubes about 1.27 cm thick. This material was specially frozen and stored at about -28.9 ° C. It was made using essentially the same thing Method and the same device as specified in Example 14, dried. The total drying time was 12 minutes.

That obtained in Example 16. Product was hneter of excluding * quality. The moisture content was ezew 1.570 / 0 (total) and the fat content 16.960 / 0 (total). The density was 0.86 g / ccm uncorrected and 0.70 g / ccm corrected. The oil content per unit volume was 146 mg / ccm. The product was slightly re-moistened on contact with water at 60 ° C. His weight gain was 740/0 in one minute, 89% in 10 minutes, 91% in 30 minutes and 96% in 60 minutes. In contrast to the very fragile character of cooked chickens which were dried by the freeze drying process, the product according to the invention was not very fragile and could be handled without excessive fines.

Example 17 As a starting material, boiled shrimp or crab was used used, which previously peeled and veined and frozen to -28.9 ° C had been. Before treatment by the method according to the invention, they were divided, each half being no more than 9.52 mm thick. It became the same Procedure and laboratory equipment used as in Example 14. The Charge ratio was 0.454 kg frozen shrimp for each 4.54 kg hydrogenated Vegetable cooking fat. The temperature was the same as in Example 13 and the total time drying took 30 minutes. Centrifugation under vacuum was used.

The product obtained in this Example 17 was excellent Quality with good color and flavor retention. The moisture content was 1.04% (total) and the fat content 38.36% (total). The density was 0.43 g / cem and the oil content per unit volume was 165 mg / ccm. In contrast to those after the freeze-drying process dehydrated shrimp was. the product is not very brittle and withstood the Handling without excessive formation of fines. When in contact with water of At 60 ° C it was rewetted easily and completely. So was his weight gain 103% in one minute, 150% in 10 minutes and 150% in 30 minutes.

Example 18 Fresh salmon was used as the starting material. To This was stewed and drained cut into cubes approximately 1.27 cm thick and frozen at -28.9 ° C. He was then made using the same device and dried by essentially the same procedure as described in Example 13. The feed ratio was 0.454 kg of product for each 4.54 kg of hydrogenated Vegetable cooking fat at an initial temperature of 182 ° C. The oil temperature was noticeable about 114 ° C and was maintained for the remainder of the work process. The total drying time was 30 minutes. Immediately after the drying process the material was then centrifuged under vacuum as in Example 4.

The product obtained in Example 18 above was excellent Quality with good color and flavor retention. The moisture content was 0.56 0/0 (total) and the fat content 39.33 0/0. The density of the product was 0.64 g / ccm not corrected and 0.35 g / ccm corrected. The oil content per unit volume was 252 mg / cc. The product became on contact with water at 60 ° C easy re-moistened. Its weight gain in one minute was 79%, in 10 Minutes 82 0/0, in 30 minutes 89 Oh, and in 60 minutes 90 0/0. Although the fat content was relatively high, this is not the case with a dried meat or fish product uncomfortable, especially since Salm normally has a significant percentage contains natural fat.

Example 19 Common maraschino cherries were used as the starting material. 68 kg of cherries were quenched to -15.0 ° C. after draining. At this temperature they were solid, but they did not appear to be frozen. The apparatus used was essentially that shown in FIG. 4 and was operated as described in Example 4. 68 kg of the quenched cherries were placed in 1360 kg hydrogenated vegetable oil at 143 ° C. The vacuum applied was approximately 67.3 cm of mercury. The temperature of the oil immediately dropped to about 88 ° C, and this temperature was maintained during the remainder of the operation. During the first 4 minutes of the operation, the partial vacuum dropped to about 64.7 cm and then returned to 69.8 cm, where it was maintained for the remainder of the work process. The total duration of the drying process was 15 minutes plus 3 minutes for pumping out oil. Sieve 64 was lowered during the last 4 minutes of the run. After the free oil was removed by pumping, the centrifuge was operated under vacuum to remove additional oil. The vacuum was then opened and the product removed.

The product made in the previous example was excellent Quality with good color and flavor retention. Its moisture content was about 5%. It was easily and completely re-moistened upon contact with warm water.

Example 20 Common canned pineapple pieces were used as the starting material. Each piece was no more than about 1.27 cm thick. 56.7 kg of these pineapple pieces were frozen to -17.8 ° C. in the drained state. The device used was that in FIG. 4 shown similar and was made in the same way as in the case; game 4 described, operated. 56.7 kg of the frozen pineapple was placed in 1360 kg hydrogenated vegetable oil which had been heated to 146 ° C. The oil temperature dropped to 71 ° C, then returned to and was held at 85 ° C. ; The initial partial vacuum applied was approximately 69.8 cm of mercury, dropped to 63.5 cm, and then returned to 71.1 cm during the first 4 minutes of the drying process. The total time for drying was 40 minutes plus 3 minutes for draining the oil. The sieve 64 was sunk under the oil surface about 30 minutes after the start of work. Example 21 As a starting material, dates which had been sun-dried were used. and had a fire content of about 20%. The dates were cleaned, grained and divided into quarters. These quarters were soaked in cold water for 2 hours during which the moisture content rose to about 35%. After allowing the free water to drain, the remoistened particles were frozen by the individual quick freeze method and stored at -17.8 ° C. They were then processed according to the method according to the invention, using an apparatus similar to that in FIG. 4 was used. The initial oil temperature was 160 ° C and the initial partial vacuum was about 68.6 to 71.1 cm of mercury. The oil temperature dropped rapidly to about 82 ° C, whereupon the temperature was raised to about 90 ° C by heating; this temperature was maintained during the remainder of the work process. The ratio was 0.907 kg of frozen material for every 4.54 kg of oil. The overall drying process took about 10 to 12 minutes. At the end of the drying process, the free oil was pumped out of the container, the product was allowed to drain and the vacuum was then removed. The product was then air cooled to 49 ° C and centrifuged in a 45.72 cm diameter drum at 600 rpm for about 2 minutes.

The product obtained in the above example was excellent Quality and echoed a porous structure in contrast to the compact structure from usually dried dates. It became light on contact with warm water re-moistened. The volume was slightly larger than the volume of the starting material.

Example 22 As a starting material, dried wheat was used. He was subjected to a grinding operation to remove shells and bran parts. It was re-moistened by soaking in an aqueous liquid made from hydrous meat extract. Approximately 1.36 kg of liquid was used to soak each 0.454 kg of wheat. The liquid was prepared by dissolving 28.35 g of dried meat extract, 14.17 g of powdered gelatin and 14.17 g of salt in 1.36 kg of water. During hydration, the liquid was heated to about 93 ° C and contact with the liquid was maintained at that temperature for about an hour. Free liquid was then drained from the re-moistened material and the material was frozen by the individual rapid freezing method to form a free flowing material which was stored at -17.8 ° C. This material was then processed according to the method of the invention using an apparatus similar to that shown in FIG. 4 shown was the same. The feed ratio was 0.454 kg of material for every 2.72 kg of oil. The oil consisted of hydrogenated cottonseed oil mix with an initial temperature of 182 ° C. The initial vacuum applied was 69.8 cm of mercury. The total time of the drying process was about 10 minutes. The oil temperature dropped rapidly to 82 ° C and was then held at about 90 ° C for the remainder of the operation. In the first few minutes there was an initial drop in the applied partial vacuum and then the partial vacuum was maintained at about 71.1 cm of mercury. At the end of the drying process, the oil was drawn off the material and the material was centrifuged in a drum with a diameter of 17.78 cm at 1100 rpm. The vacuum was then opened.

The product obtained in the above example was porous and free fluently. It was quickly remoistened into the ingredients without physical dissolution. When it was placed in a kettle with water heated to 100 ° C and was held at this temperature for 5 minutes, humidification was with boiling and completely with retention of the natural grain shape.

Example 23 As a starting material, ravioli with a filling were used made of grated, boiled meat and cooked vegetables and a casing used uncooked dough. The dough shell was on both the top and the perforated on the underside, whereupon the ravioli individually frozen to -12.2 ° C became. The frozen product was then subjected to the method according to the invention, a device similar to that in FIG. 3 was used. the Initial oil temperature was 116 ° C and the proportions were 3.63 kg of ravioli 45.4 kg each of hydrogenated vegetable oil. The partial vacuum applied was 71.1 cm of mercury. After the introduction of the ravioli, the oil temperature dropped to about 71 ° C, and by adding more heat the temperature was increased to about 99 ° C, where it was kept for the rest of the workflow. The total length of time for the drying process took 15 minutes. After removing the ravioli from the Oil they were drained under vacuum to remove excess oil. The vacuum was then released.

The dried ravioli obtained in the previous example were a high quality product, which when immersed in warm water was slightly re-moistened. The moisture content was about 4%. To this It is not necessary to prepare the product for an extended period Soak in water for a period of time. The ravioli are just put in a pan with water given and brought the water to the boil.

Example 24 The following is an example of a batter formulation. A wet dough was made by mixing the following ingredients together: 2 cups of wheat flour, 4 teaspoons of baking powder, 1 teaspoon of salt, 1 tablespoon of shortening, 2 / s cups of whole milk.

After homogeneously mixing, the dough was turned into a layer of dough rolled out, which was gouged out to form round slices, each of which was about 6.35 mm in diameter and 6.35 mm in thickness. The particles were individually frozen and stored at -17.8 ° C. They were following the procedure processed according to the invention, wherein a device as in F i g. 4 shown was used. The loading ratio was 0.907 kg of dough disks for each 45.4 kg hydrogenated cottonseed oil at 149 ° C. The initial vacuum was 71.1 cm Mercury column. Shortly after the feed was introduced, the temperature dropped about 82 ° C and was brought back to about 90 ° C by the application of heat, where it was held for the remainder of the operation. In a total drying process after 9 minutes the moisture content was lowered to below 5%.

The dried dough product made according to the previous example was produced had a volume of. about twice the volume of the initial disks due to fermentation during treatment. Took on contact with warm water it quickly watered up again. It was for making dumplings and for use suitable in stews and similar food mixes. Centrifuge under Vacuum was used to reduce the oil content.

Example 25 The starting material and procedure are the same as in Example 24. However, the slices were baked a short time before freezing out subjected to activate fermentation and to form the crumb structure of the dough.

Example 26 The starting material consisted of fresh sweet corn kernels which were cut from the cobs and frozen by the individual rapid freezing process and stored at -15.0 ° C. The device used was similar to that in FIG. 3 shown. A quantity of frozen corn was placed in hydrogenated cottonseed oil at a temperature of 182 ° C while applying a vacuum of 66.0 cm of mercury. The feed ratio was 0.454 kg of frozen corn for each 4.54 kg of oil. The applied partial vacuum was allowed to rise to about 71.1 cm of mercury over a period of about 2 minutes. After a period of 4 minutes. after the corn mass was introduced, the oil was removed from the container and the corn allowed to drain while maintaining the application of vacuum. This took about 15 seconds. A fresh amount of oil at 104 ° C was then placed in the container. About 3.63 kg of oil was replaced in this way for every 0.454 kg of the original starting material. The second oil consisted of hydrogenated cottonseed oil which had been clarified and contained approximately 20% dairy butter. After the introduction of the second mass of oil, the operation was continued under a 71.1 cm partial vacuum for a period of about 10 minutes. At this point the oil was pumped out of the container, leaving a dried product in the centrifuge drum, and then allowed to spin the centrifuge for about 3 minutes while maintaining the vacuum at about 71.1 cm. The product obtained in the above example was of excellent quality with a porous structure. It easily absorbed water again on contact with warm water. It had a good taste and could be eaten without further processing.

Example 27 The same starting material and procedure were used as used in example 26. However, at the end of the centrifugation operation the applied partial vacuum is increased to just above 73.7 cm of mercury and held there for a period of about 3 minutes, whereupon the vacuum through the inflow of air that has been de-humidified is removed became. The obtained grains were found to be considerably puffed up. In the same way it was found that the grains immediately upon their removal at a temperature on the order of 49 ° C, as opposed to a product temperature from 54 to 60 ° C for the product produced in Example 26 at the time of its removal. This example illustrates the puffing and cooling effects that result from Use a relatively high vacuum at or near the end of centrifugation is obtained. A higher vacuum than that specified would reduce the temperature of the outgoing Lower the product to below 49 ° C, which is, however, with the evacuation or suction device cannot be achieved.

Example 28 The same starting material and essentially the same procedure as in Example 6 were used. However, after pumping all of the oil out of the container and operating the centrifuge for about one minute out of the 3 minutes of the centrifugation period, water was introduced into the container through line 47 in an amount equivalent to 226.8 g for every 0.454 kg of frozen material. This is used to reduce the temperature of the metal of the centrifuge drum from 77 to 40.5 ° C. After the application of the vacuum, the temperature of the outgoing product was about 60 ° C., whereas the same process, but without the introduction of water, a temperature in the outgoing product of about 68 ° C.

The in the F i g. 6 to 16 shown photomicro; graphic representations illustrate dried products made according to certain of the preceding examples have been manufactured.

F i g. 6 shows a photomicrograph (327x magnification) a potato produced according to Example 5. The cell structure is evident from one relative integrity with the exception of a significant wrinkle. Starch grains do not appear because they are gelatinized. Some of the dark stain areas in the upper right corner represent separate masses of oil. In a color photomicrograph several oil masses of the same sample can be seen if the product is with an oil with a dye content. Most of the oil masses reside in the outer areas and in the intercellular spaces that make up the cell walls mounting. Fi g. 7 shows the same product, but with a higher magnification (674x Enlargement). Tiny masses of oil appear in the lower left area (not to be confused with the larger, bubble-like areas with black edges).

F i g. 8 shows a photomicrograph (magnification x 74) of celery prepared according to Example 10. The spongy tissue of the paremchymal cells is clumped together and appears as vein-like structures with empty spaces in between. They can be seen as dark areas in the right part, in the lower left corner, and something in the middle part. More fat masses can be seen on a color photomicrograph. The xylem vessels, which form the surface ribs of the celery, appear unchanged.

F i g. 9 is a photomicrograph (magnification x 74) of a mushroom stem piece; which was prepared according to Example 13. Some of the mycelial fibers appear to be vein-like Structures to be condensed. The remaining Fawrn are somewhat condensed with small ones intermediate air pockets. Tiny separate masses of oil mainly occur in the surface areas and in the blackened areas of the photomicrograph on. Individual masses of oil can be seen in a color micrograph.

F i g. 10 is a photomicrograph (magnification x 74). Which shows a chicken sample prepared according to Example 16. The Z. II structure appears in both photomicrographs and is practically the same as in the starting material. Separate masses of oil appear as dark spots in the lower middle part and in the right one Part. You will be more visible on a color micrograph which is of a product which was processed with oil with a dye content was made.

F i g. Figure 11 shows a chicken sample like Figure 11. 10 at 327x magnification after extraction of the oil content. The light lines give the cell tissue undisturbed Pattern again.

F i g. 12 shows a photomicrograph (32X) of FIG Beef which was produced according to Example 15. The cell structure is practical the same as in the starting material. The separated oil masses (on a color micrograph only visible) are randomly distributed.

F i g. 13 is a photomicrograph (magnification x 327) of a shrimp sample prepared according to Example 17. The fat content was extracted from the cut sample. The cell structure is similar to that of the starting material. Separate fat masses appear in the color photomicrograph and are randomly distributed in the surface areas, with some being present in the intercellular spaces.

F i g. 14 shows a photomicrograph (magnification 74X) of FIG Blueberries produced according to Example 4. The spongy cell tissue which representing the interior of the berry shows a certain disruption with formation of Fibers that are either connected to the seed or directly on the inside occur on the skin. Separate fat masses shown only in a color photomicrograph can be seen, are arranged in the denser cell structure around the seed and also inside the sponge-like fabric and directly on the inside of the Skin.

F i g. 15 is a photomicrograph (magnification x 74) showing that prepared according to Example 8 Carrot product and in particular the outer phloem shows. The fat content was extracted from the sample. The cells both the outer and inner phloem are practically the same as in the starting material. Other cells show a certain disruption and branching into vein-like structures. Tiny discrete masses of fat are seen as seen on a color photomicrograph distributed arbitrarily, but are mainly found in the inner P'hloem- and outer bark layer.

F i g. 16 is a photomicrograph (magnification x 74) showing a salmon sample prepared in accordance with Example 18. FIG. The cell structure is the same as in the starting material. Separate fat masses are accommodated in any distribution in the intercellular spaces. They show up in the dark stain areas that appear in the upper right corner, in the upper middle part and lower middle part.

In general, the foregoing photomicrographs confirm what above with regard to the properties of the process according to the invention manufactured products.

When performing the method described above, the The drying process is completed after the partial vacuum has been broken off. In the Treating certain products it was found beneficial to the above Drying process for the rapid removal of the major part of the moisture beforehand apply and then the further moisture by a certain other Procedure to remove. So the drying can be done using hot oil under Vacuum can be brought to completion when the material is of sufficient strength for handling (e.g. 15 to 5011 / o moisture content depending of the material), and then a further drying to reduce it the moisture content to a lower value (e.g. 1 to 5%) will. Preferably, centrifugation under vacuum is used before vacuum removal, to reduce the residual oil content. Production drying is also preferred Carry out in such a way that the damage to heat-sensitive and oxidizable Ingredients is reduced to a minimum, creating a finished product of good quality Quality is produced. It turned out to be satisfactory, the finished drying Perform by conventional vacuum drying, placing the material on drying trays is spread and the drying trays are evacuated from heated lockers Space to be worn. With a suitable device, vacuum drying in a gaseous atmosphere at the end of the oil drying operation after centrifugation and continued without removing the applied vacuum. Although the finished drying under vacuum is desired, it will be apparent that other modes of drying could be used can be, such as B. Contact of the product with warm air or another Atmospheric pressure gas.

If the second drying in a gaseous atmosphere after the Oil drying operation is used, there is a special collaboration, in that the product is porous at the end of the first oil drying process and therefore its porous structure allows subsequent drying in a gaseous atmosphere very relieved. The oil content, which is arbitrary in the form of tiny, separated Mass is distributed, does not counteract the development of moisture.

It has been found that using the method in the just described way on substances such as fresh Chinese pea pods the end product has greater resistance to breakage or abrasion.

Claims (31)

Claims: 1. Method for drying moist food, characterized in that particles of a moist nutritional material are poured into a hot Medium can be enveloped under partial vacuum, the medium consisting of a foam-like Mixture consists of steam and hot oil and the oil is at one temperature significantly above the evaporation point of the moisture in the material the applied partial vacuum is so that moisture develops quickly from the material and then free oil is separated from the dried material. 2. The method according to claim 1, characterized in that a major part of the moisture is removed while the material is immersed in the medium, and then Further moisture is removed by turning the material into liquid with hot oil Phase is brought into contact under partial vacuum. 3. The method according to claim 2, characterized in that the oil with which the material to remove further Moisture is brought into contact is at a temperature which significantly below the initial temperature of the oil mentioned first, but above the evaporation point of the moisture in the material at the partial vacuum applied lies. 4. The method according to any one of claims 1 to 3, characterized in that the material is separated from the free oil while applying a partial vacuum is continued, and then the vacuum is released. 5. Procedure according to one of claims 1 to 4, characterized in that a centrifugal force the material is applied to separate free oil from it before the applied Partial vacuum is canceled. 6. The method according to claim 4 or 5, characterized in that that the temperature of the material after the separation of the free oil from the material and before the vacuum is released by further evaporation of moisture Achieving evaporative cooling is reduced. 7. The method according to claim 6, characterized in that the cooling by evaporation using a vacuum higher than that applied during the bulk of the drying cycle Vacuum is carried out. B. Method according to claim 4 or 5, characterized in that that the dried material after separation of the free oil from it and before The release of the vacuum is cooled by adding water to the ingested by the material Introduced evacuated space and instantly transition into steam with absorption brought by warmth. 9. The method according to any one of claims 1 to 8, characterized characterized in that the starting material at the time of its initial contact with the Medium has a temperature below 0 ° C. 10. The method according to any one of the claims 1 to 8, characterized in that the moist starting material at the time of his Initial contact with the medium is frozen and that the temperature of the oil after this initial contact is rapidly diminished, with the bulk of the moisture of the material is removed during the first part of the evaporation process. 11. Method according to claim 1, characterized in that the starting material is at the first contact with the hot oil is frozen in the foam-like medium and then the material with a second oil through which at least one Part of the first oil is replaced, is brought into contact, so that another Moisture removal takes place while maintaining the applied partial vacuum will. 12. The method according to claim 11, characterized in that the second is hot Oil is clarified. 13. The method according to claim 1, characterized in that the drying process by feeding a batch of frozen food material into one evacuated space and causing it to fall into hot Oil is introduced into this space, with the hot oil at an elevated initial temperature is present, which is significantly above the evaporation point of moisture at the applied partial vacuum, creating the foam-like mixture of water vapor and hot oil is formed and the charge gradually increases as it is introduced this medium is dropped. 14. The method according to claim 2 or 3, characterized characterized in that the initial temperature of the oil is of the order of between 116 and 316 ° C and the temperature of the oil to remove further moisture in of the order of 77 to 110 ° C. 15. The method according to claim 4 or 5, characterized in that after separating the dried material from the free oil the vacuum is broken by supplying an anhydrous gas. 16. Method according to claim 15, characterized in that the anhydrous gas is a is inert gas. 17. The method according to claim 4 or 5, characterized in that an impregnating agent for the dried material at the end of the process supplied and then the vacuum is released, so that the impregnating Means to penetrate the material. 18. Procedure according to one of the Claims 1 to 17, characterized in that the food material of a preceding Treatment to reduce its moisture content is subjected to before it is introduced into the hot oil. 19. The method according to claim 18, characterized in, that the food material is subjected to rewetting and then to Preparing for the introduction to the hot oil being frozen. 20. Procedure according to Claim 10, characterized in that the moist food material is in a partial vacuum immediately before and during freezing is subjected, causing the material expanded and frozen in expanded form. 21. The method according to any one of the claims 1 to 20, characterized in that the material immediately after its introduction in the hot oil is uninhibited and free to move about. 22. Procedure according to one of claims 1 to 21, characterized in that the material according to Removing a substantial amount of the moisture content from the free oil separated and then the present in porous form material to another Drying in a gaseous atmosphere to remove additional moisture is exposed. 23. Device for performing the method according to one of the Claims 1 to 22, characterized by a container device for receiving hot oil and the material to be dried, the condensation and evacuation facilities connected to maintain a partial vacuum and the devices for the Introducing a load of the material to be dried during the partial vacuum is maintained in the container device, as well as devices for removal of oil! and dehydrated material. 24. Apparatus according to claim 23, characterized by a sieve device within the container device, which between a position in which it does not allow the movement of the material disturbs,: and is movable to a second position in which it extends over the container device extends to the floating of the material at a level above the screening device to prevent. 25. The device according to claim 24, characterized in that the Sieve device is rotatable to move it between the two working positions. 26. The device according to claim 24, characterized in that the sieve device can be moved vertically between the two positions. 27. Apparatus according to claim 23, characterized in that the device for introducing the to be dried Feed material a closed hopper for receiving the feed with feeding devices for the gradual discharge of the load into the container device wherein the hopper is in communicating connection with the container stands. 28. Device according to one of claims 23 to 27, characterized in that that the device for the removal of oil and dried material a pipe system from the container to remove the oil from the container at the end of the drying process and a perforated device within the Contains container on which the dried material is deposited. 29. Device according to claim 28, characterized in that the lower part of the container is a detachable vessel in which the foraminous device is mounted is and wherein the piping system with this vessel is below the holes provided Device is connected. 30. The device according to claim 29, characterized in that that the perforated device consists of a rotatable centrifuge drum consists. 31. Device according to one of claims 28 to 30, characterized in that that they have means for introducing water into the device for rapid cooling at the end of the drying process.