CN1068771C - Method of preserving food or the like in nonfrozen state in temperature zone below icing point - Google Patents

Abstract

In a non-freezing area below the freezing point of food or the like, the method of preserving perishable food or the like in a non-frozen state includes cooling it from the normal temperature to near its freezing point relatively quickly, and then cooling it at 0.01-0.5°C/h The cooling rate cools it slowly below freezing. The method can preserve high freshness of perishable products such as vegetables, fruits, fish or shellfish, and can effectively restrain the inevitable decline of freshness immediately after harvesting. By combining the perishable products processed by the present invention with conventional low-temperature distribution and delivery methods, consumers can be provided with perishable products with high freshness and high quality, which are not affected by the immediate decline in freshness after harvesting. Perishables treated as above can remain in the hands of consumers for a long time and can be prevented from undergoing rapid spoilage like common food products. It is also possible to produce frozen products of this type which have not previously existed.

Description

Methods of non-refrigerated preservation of food at temperatures below freezing point

technical field

The present invention relates to a method for non-freezing preservation of food or the like in a temperature zone below freezing point. A method for analogues, and relates to a method for non-freezing preservation of perishable food or the like, which combines slow cooling treatment and step-by-step heating treatment, wherein the slow cooling treatment makes said perishable food or the like In a non-frozen state below freezing point, the temperature of the perishable food or the like in the non-frozen state is raised to room temperature by step-by-step heating, which can keep the perishable food or the like in the sub-freezing temperature zone A suitable non-freezing state can also maintain the effect and characteristics of non-freezing treatment, and can effectively return the food to the best room temperature. The present invention also relates to a method for increasing the temperature and so on.

Background technique

In the process of expanding the basic preservation method, and studying the preservation and processing of various perishable foods, biological tissues, etc. Concerning the preservation and processing of various perishable foods or the like in a non-freezing area below freezing point, the inventors have previously developed a method of preserving various perishable foods etc. under subfreezing conditions, and by using supercooled water for preservation and processing Vegetables, fruits, seafood and other such perishable foods etc. have been successfully used in this method. As a result of studying these methods, the inventors have found that freshly harvested vegetables, fruits, seafood, and other such perishable foods, etc., can be chilled under specific ultra-cold conditions in non-freezing zones below freezing, whereby it is possible to store The process maintains a high degree of freshness of said perishable food or the like. The inventors have also found that these methods are quite suitable for the preservation and treatment of vegetables, fruits, seafood and other such perishable foods and the like.

In general, among various foods and the like, it is particularly important that vegetables and fruits which are natural products be fresh, and the same is true for seafood. It is essential to consider the constant maintenance of the freshness and quality of these foods throughout the distribution process, from origin to market, and from market to point of sale.

Therefore, from the product stage (harvest location) to the consumption stage, the ideal way to provide fresh and high-quality products should be through the "cold chain" including specific low temperature conditions. But the actual situation is that the preservation conditions on distribution channels are not sufficient, which is due to the consideration of distribution costs, limited cryopreservation technology and so on.

As mass production and mass consumption of food products became more common, so did the needs of consumers, and as these needs increased, many different types of products appeared on the market. What this trend brings is consumers' requirements for low prices and high quality products. Consumers are also paying more attention to natural food. When natural food is vegetables, fruits, seafood and other such perishable foods, the higher requirements for its high quality are freshness and high nutritional value.

As mentioned above, many areas harvest and produce vegetables, fruits, seafood and other such perishable foods as agricultural products and seafood, and most of them reach consumers through markets and retail sales, Even now, with all our various techniques for preserving said perishable food or the like put into use, it is still difficult to maintain the freshness of the collection or the freshness obtained and freshness over a prolonged period. For example, even if distribution times could be shortened to ensure good state of preservation, the expense would be quite prohibitive at present, and would be impractical for general distribution of perishable foods, except for certain high-end products method.

Cryopreservation methods used in the distribution process, cryopreservation equipment, cryopreservation technology, etc. have been studied from various angles in the past in an effort to improve the situation, even if only a little, resulting in widespread advances in various technologies. Typical examples of these are CA storage and MA storage (Shokuhin Ryutsu Gijutsu, Vo1.22, No. 11 (1993)), and other methods have also been developed and improved. However, there is generally a sudden drop in freshness of perishable food products immediately after harvest, and there is also a reduction in freshness during distribution. Especially fruits and vegetables, useful ingredients such as vitamin C and other nutrients, chlorophyll, etc. are decomposed quickly, and for seafood, the rapid decomposition of ATP causes the K value (freshness index) to decrease, and due to These and other spoilages inevitably occur, so unless some new technology is developed that can actually suppress the immediate post-harvest loss of freshness, it will not be possible to maintain a state of near-harvest high freshness.

SUMMARY OF THE INVENTION

In view of the foregoing, the inventors have conducted assiduous research with the aim of developing a system which is better than the above-mentioned prior art and capable of keeping vegetables, fruits, seafood and other such perishable foods or the like after harvest. New technology in high freshness state. In the course of this research, they turned their attention to cooling processing of vegetables, fruits, seafood or other such foods or the like under specific supercooling conditions, and completed the present invention, successfully designing a new slow adjustment technology , with which perishable food or the like can be kept in a suitable unfrozen state simply and effectively in a non-freezing zone below freezing point, and as an effective non-frozen state food or the like in said non-freezing zone below freezing point basic technology of things.

The object of the present invention is to provide a method for non-freezing preservation of perishable foods or the like, which can maintain high freshness of vegetables, fruits, seafood and other such perishable foods, etc., without causing any freshness. temperature reduction and deterioration, and provide a slow cooling method and manner, with which the food or the like can be brought into a non-frozen state in a sub-freezing temperature region simply and effectively.

Still another object of the present invention is to provide a method for producing food or the like in a subfreezing non-frozen state by using the above-mentioned non-freezing preservation method, and a product of the method.

Still another object of the present invention is to provide a method for preserving perishable foods or the like under high freshness, with which vegetables, fruits, seafood and other such perishable foods or the like can be kept in a prolonged period of time. A non-frozen zone below freezing without causing the food to lose its post-harvest freshness.

Another object of the present invention is to provide a kind of slow adjustment technology, in the method for the perishable food of non-frozen state or similar preservation in non-freezing zone below freezing point, temperature condition is effectively controlled in said non-freezing zone and effectively Controlling temperature conditions [to bring food] to room temperature, etc.

To achieve said object, the first embodiment of the present invention is a method for preserving food or the like in a non-frozen state in a subfreezing temperature zone, wherein the method for non-freezing preservation of a food or the like in a subfreezing temperature zone It is characterized by rapid cooling treatment, that is, relatively rapid cooling of food or the like from room temperature to near freezing point, followed by slow cooling treatment, that is, gradually cooling [food] below freezing point at a cooling rate of 0.01-0.5°C/hour .

The second embodiment of the present invention is a method for preserving food or the like in a non-freezing state in a subfreezing temperature zone, wherein said method for non-freezing preservation of a food or the like in a subfreezing temperature zone is characterized in that , Introduce food or the like into a non-freezing zone below freezing point, then stop in a low temperature zone 0.1-10°C below freezing point, and preserve in this low temperature zone.

A third embodiment of the present invention is a method for preserving food or the like in a non-freezing state in a temperature zone below freezing point, wherein said method for non-freezing preservation of food or the like in a temperature zone below freezing point is characterized in that, The temperature of the food or the like is raised to the freezing point or 0.5-1.0° C. above the freezing point at an appropriate time and in an appropriate cycle during the preservation process.

The fourth embodiment of the present invention is a method for raising the temperature of food or the like preserved in a non-frozen state in a subfreezing temperature zone to room temperature, wherein said raising the temperature of the non-frozen food or the like in the subfreezing temperature zone The method is characterized in that the temperature is raised at a rate of 0.01-0.5°C/hour, gradually raised to close to the freezing point, and then raised from the freezing point to room temperature, the temperature raising condition is set to an appropriate temperature, and the temperature is raised in stages at an appropriate number of times.

A fifth embodiment of the present invention is a cooling apparatus provided with control means for automatically controlling temperature conditions.

The sixth embodiment of the present invention is a method for producing non-freezing water in a temperature zone below freezing point by the above method, wherein the method for producing non-freezing water in a temperature zone below freezing point is characterized in that the raw material water is purified by microfiltration or the like in advance Filtration and/or distillation to remove impurities from raw water.

The seventh embodiment of the present invention is a method for producing a non-frozen food or the like in a subfreezing temperature zone by the above method, wherein said method for producing a non-frozen food or the like in a subfreezing temperature zone is characterized in that, in a specific pressurized Cooling food or the like is processed under conditions by slow cooling at a gradual cooling rate of 0.01-0.5°C/hour.

The eighth embodiment of the present invention is the above method for preserving food in a non-frozen state or the like in a subfreezing temperature zone, wherein said method for non-freezing preservation of a food or the like in a subfreezing temperature zone is characterized in that, irradiating [food] with far-infrared rays, microwaves, or other such rays at appropriate times during preservation, irradiating with static electricity, and/or vibrating in a temperature zone above the point of destruction, in order to bring about a subfreezing supercooled state Stablize.

A ninth embodiment of the present invention is a cooling apparatus incorporating means for applying pressure, radiation and/or vibration.

The tenth embodiment of the present invention is the above method for preserving non-frozen state food or the like in the subfreezing temperature zone, wherein said method for non-freezing preservation of the food or the like in the subfreezing temperature zone is characterized in that the food or the like, which have been packaged or covered with a packaging material such as synthetic resin, paper or biological material; In addition, the packaging material for inhibiting the growth of ice crystals is packaged or covered; or it is packaged or covered with a film covering these substances.

The eleventh embodiment of the present invention is a method for preserving food or the like consisting of animal or plant material in a subfreezing non-freezing zone, only the inner cells thereof are in a non-freezing state, wherein said subfreezing temperature zone is not The method for freezing and preserving the internal cells of food or the like is characterized in that the rapid freezing treatment is combined with the above non-freezing preservation method, and as a result, the food or the like is quickly frozen from a supercooled state below the freezing point, resulting in damage to the food or the like. The outer cells are frozen, while the inner cells are preserved in a non-frozen state.

The twelfth embodiment of the present invention is a method for producing a frozen food or the like from a food or the like preserved in a non-freezing state in a non-freezing zone below freezing point, wherein said method for producing a quick-frozen food or the like is characterized in that That is, combining the quick freezing treatment and the above non-freezing preservation method, as a result, the food or the like is subjected to the quick freezing treatment from a supercooled state below the freezing point, so that the food or the like is quickly frozen.

Another embodiment of the present invention is a method for producing non-freezing water in a subfreezing temperature region by the above method, wherein said method for producing nonfreezing water in a subfreezing temperature region is characterized in that during the cooling step, the raw material is preferably The flow rate of water is 0.1-2000m/min, thereby preventing the formation of ice nuclei and the growth of ice crystals.

Another embodiment of the present invention is a method for thawing frozen food in advance and obtaining high-quality thawed food by heating up in stages with a suitable number of times, wherein the method for thawing the thawed food is characterized in that damage to cells or tissues is inhibited [ Thaw the food] gradually, and at the same time raise the temperature in stages after gradually thawing, and keep the non-frozen components in the frozen food in a supercooled state (1-10°C below the freezing point) while raising the temperature in stages.

The present invention will be further described in detail.

As described above, the present invention is to preserve foods or the like (such as vegetables, fruits, seafood and other such perishable foods, and foods composed of animal or plant materials, in a non-frozen state in a non-freezing zone below freezing point, various A method of processing food, food raw material, raw water, animal or plant biological material, biological tissue, etc.), and a method of non-freezing preservation of food or the like, characterized in that first a rapid cooling treatment is carried out, that is, the food or The analogue is cooled relatively rapidly (within 1-30 minutes or hours) from room temperature to close to the freezing point of said perishable food or similar, followed by slow cooling, i.e. [food] at 0.01-0.5°C/hour The cooling rate gradually cools below the freezing point. In the present invention, "a method of preserving food or the like in a non-frozen state in a non-freezing zone below freezing point" refers to a preservation method comprising the presence or absence of a freezing point depressant, a component having a freezing point depressing effect, or a component having the same effect (sub-freezing preservation method (“sub-freezing” is a registered trademark)), the ultra-slow cooling of foodstuffs by a step-by-step cooling process whereby various foodstuffs or the like are converted from non-frozen regions below freezing to non-frozen state. Regardless of its method or manner of treatment, any method having the same effect as the stated method should also be considered. Therefore, there are no particular limitations on the type and use form of the freezing point depressant, the component having a freezing point depressant effect, and the like.

According to the research conducted by the inventors, it was generally difficult to keep food or the like in the sub-freezing temperature zone in the past in a non-frozen state, but due to the above-mentioned slow adjustment technique, it is possible to keep the food or the like at the freezing point in a simple and effective manner. The following temperature zones remain non-freezing. With the present invention, it is possible to expand the freezing zone below the freezing point (low freezing zone) irrespective of the kind of food or the like. The present invention is particularly suitable for vegetables, fruits, seafood and other such perishable foods, but is not limited thereto, and can also be applied to fermented foods, processed foods, food raw materials, semi-finished products, cooked foods, animal or plant biological materials, biological tissues ( cells or tissues of animals or plants), etc. In the present invention, as long as a relatively fast freezing process can be realized in a low temperature zone below 0°C, and as long as a slow cooling process can be realized at a rate of 0.01-0.5°C/hour, preferably 0.01-0.4°C/hour to below freezing point, it can be Using any method of cooling food or the like in a temperature area below freezing point other than the freezing zone, the method is not particularly limited, but a suitable example is by means of a control device equipped with automatic temperature control (automatic temperature control The cooling equipment of device) realizes this cooling method.

When the perishable food or the like is cooled by the above-mentioned rapid cooling treatment and slow cooling method, it is preferable to gradually cool the perishable food or the like below the freezing point so that the perishable food or the like is stabilized at a temperature below the freezing point. Unfrozen areas are not frozen and remain effectively unfrozen. In addition, the research of the inventors of the present invention has shown that when the above-mentioned slow cooling treatment conditions and processes are not used, that is to say, when the slow cooling treatment is not performed at a rate of 0.01-0.5° C./hour to gradually cool below the freezing point, it is difficult The subfreezing temperature zone keeps the food or the like in a non-frozen state, and thus fails to achieve the stated purpose.

In the present invention, food or the like is introduced into a non-freezing zone below the freezing point, then stopped in a low temperature zone of 0.1-10°C below the freezing point, and preserved in this low temperature zone for several hours to several months, but due to the The appropriate range of the low temperature zone varies significantly with the type and nature of the food or the like, and it should be appropriately set according to the food or the like. Based on the experiments of the slow adjustment technique of the present invention described above, examples of the freezing point of various foods and the like and the non-freezing region (sub-freezing region) below said freezing point will be given below.

Sub-freezing zone for various food products or the like:

Food or similar Freezing point (°C) Sub-frozen zone (°C) Vegetables

Tomato -0.9 -0.9 to -5.0

Onion -1.1 -1.1 to -6.0

Peas -1.1 -1.1 to -6.5

Cauliflower -1.1 -1.1 to -7.0

Potatoes -1.7 -1.7 to -13.0

Sweet potato -1.9 -1.9 to -15.0

Asparagus -0.6 -0.6 to -5.0

Light white (wh-ite onion)-0.8 -0.8 to -6.0

Lettuce -0.2 -0.2 to -4.0

Daikon (Japanese radish) -0.8 -0.8 to -6.0 fruit

Persimmon -2.1 -2.1 to -15.5

Apple -1.5 -1.5 to -15.0

Lemon -2.2 -2.2 to -18.0

Cherry -2.4 -2.4 to -18.0

Asian pear -1.5 -1.5 to -15.0

Strawberry -0.9 -0.9 to -6.0

Fig -2.4 -2.4 to -17.5

Peach -0.9 -0.9 to -7.5

Purple Black Berries -1.3 -1.3 to -15.0

Apricot -1.1 -1.1 to -13.0 seafood

Puffer fish -1.5 -1.5 to -15.5

Jaw trevally -1.5 -1.5 to -15.5

Mackerel -1.5 -1.5 to -15.5

Sardines -2.0 -2.0 to -18.0

Cod -1.2 -1.2 to -15.0

Monofin liner -1.2 -1.2 to -15.0

Flounder -1.2 -1.2 to -15.0

Snow crab -2.2 -2.2 to -18.0

Scallops -2.2 -2.2 to -18.0 Animal products

Beef -1.7 -1.7 to -18.0

Pork -1.4 -1.4 to -15.0

Chicken -1.3 -1.3 to -15.0

Milk -0.5 -0.5 to -8.0

Butter -2.2 -2.2 to -19.5

Cheese -8.3 -8.3 to -25.0 Processed foods

Preserved Foods -3.0 -3.0 to -18.0

Fermented soybeans -3.1 -3.1 to -18.0

Adult Cuttlefish -5.3 -5.3 to -20.0

Bread -5.0 -5.0 to -20.0

Beer -2.8 -2.8 to -17.0

With regard to the food or the like targeted by the present invention, perishable foods such as vegetables, fruits, animal products, seafood or the like can be any common vegetables, fruits, animal products, seafood, and the use of the present invention and its varieties irrelevant. In addition, "perishable food or the like" in the present invention also includes fresh flowers, Chinese herbal medicines, rice bran and other grains, nuts and similar foods and plants related thereto, and the like. When the present invention is used to keep perishable food or the like fresh, it is important that the perishable food or the like be handled as soon as possible after harvesting. This effectively suppresses the inevitable loss of freshness immediately after harvesting of perishable foods or the like, which in the case of fruits and vegetables means the rapid breakdown of useful components such as vitamins and other nutrients, chlorophyll, etc. , while for seafood, it refers to the decrease of K value (freshness index) and other similar deterioration due to the rapid decomposition of ATP. Here "immediately after harvest" refers to the stage immediately after the harvest of perishable food at the harvest or place of production, but since the reduction in freshness immediately after harvest varies greatly depending on the type of perishable food or the like, harvest season and other factors , so the timing of cold storage treatment should be appropriately determined according to the targeted perishable food or the like. Generally speaking, the above cold preservation treatment should be completed within a few hours after harvest. Furthermore, the present invention is not limited to the treatment of perishable food products or the like immediately after harvesting, but is naturally equally applicable to perishable food products or the like at appropriate locations during the distribution process, or perishable food products or the like at the consumption stage. things.

For placing perishable food or the like in a non-refrigerated area below freezing, it is preferably handled at the point of harvest or production, however, it is also possible, for example, to load the food or the like onto a truck or similar vehicle equipped with cooling equipment , and transported to the processing site, it is also possible to process perishable food or the like at the site where a large cooling facility is set up.

In the present invention, under the above-mentioned supercooling conditions, the freshly harvested perishable food or the like is subjected to non-frozen cold storage treatment in a non-freezing zone below the freezing point, which can effectively suppress the freshness decline of the perishable food immediately after harvesting, and is beneficial to For fruits and vegetables, the immediate decrease in freshness refers to the rapid decomposition of useful ingredients such as vitamins and other nutrients, chlorophyll, etc., while for seafood, it refers to the decrease in K value (freshness index) and other factors caused by the rapid decomposition of ATP. Similar spoilage can also provide high freshness and high quality that cannot be obtained by conventional preservation methods for perishable foods or the like.

In addition, according to studies by some of the inventors, even if perishable food or the like is maintained in an ordinary preservation state after the above-mentioned cooling treatment, the decrease in freshness is remarkably suppressed, and high Freshness.

In the method for preserving food or the like in a non-frozen state in a non-freezing zone below the freezing point of the present invention, it is also possible to simply and effectively keep the food or the like in a non-frozen state by adding a step, which is during the preservation process. , raising the temperature to the freezing point or 0.5-1.0°C above the freezing point at a rate not exceeding 1°C/(one hour-a few days) at a suitable time and with a suitable cycle. Therefore, it is desirable to make the non-freezing state more stable by adding said temperature raising step to the above-mentioned method of the present invention for non-freezing preservation of foodstuffs or the like in the subfreezing temperature region.

In order to return the temperature of the food or the like preserved in the non-freezing state below the freezing point to room temperature, the present invention does not heat the food or the like rapidly, but carries out a temperature-raising treatment at a rate of 0.01-0.5°C/hour. The rate is raised to the freezing point, and then from the freezing point to room temperature, and the heating conditions are set to appropriate temperatures of 0°C, 5°C, and 15°C, so that the temperature can be raised in stages with appropriate times. In this case, it is also possible to raise the temperature to be raised from freezing point to room temperature at a relatively high rate, but the [rate] should be appropriately set according to the type and nature of the food or the like.

The form of the food or the like of the present invention is not limited to solid food or the like (including powder, etc.), but also applicable to the liquid food or the like, such as alcoholic and non-alcoholic beverages, tea beverages and drinking water. For example, the method of the present invention can be used for drinking water to produce non-frozen water below freezing point (0°C). At this time, the raw material water can be filtered and/or distilled to remove impurities in the raw material water by suitable methods such as microfiltration, fine filtration, ultrafiltration, etc., so that the non-freezing zone below the freezing point can be expanded stably and simply. Furthermore, a flow rate of 0.1-2000 m/min can be imparted to the raw water during the cooling step, and the formation of ice nuclei and the growth of ice crystals in the raw water can be prevented.

In addition, in order to more stably preserve food or the like in a non-frozen state in a non-freezing zone below the freezing point, that is, to stabilize a supercooled state below the freezing point, it is advantageous to add a step of using Far-infrared rays, microwave or other ray radiation [food], electrostatic radiation and/or continuous or discontinuous vibration in the temperature zone above the destruction point (the lower limit of the non-freezing zone). There are no particular limitations on treatment conditions, methods or manners of light radiation, electrostatic radiation and/or vibration, as long as they can extend a subfreezing non-freezing region, but conditions, methods and equipment should be appropriately selected.

In addition, in the present invention, in order to make the cooling more gentle and prevent damage caused by ice crystals, the packaged or covered food or the like can be cooled to a specific low temperature area, wherein the package can be made of polyethylene or other synthetic resins, Japan Packaging of paper or other types of paper or biological material; or of suitable material capable of satisfying gradual cooling conditions and preventing overcooling of food parts; or of packaging covered with an inner film including glycerin or other ice nucleation inhibitor , glycoprotein, gelatin, or other suitable chemical substances that inhibit the growth of ice crystals; or coatings with these substances. When these wrapping or covering materials are used in the present invention, it is possible to achieve an extended subfreezing non-freezing zone and a more stable non-freezing state in said zone.

Furthermore, the present invention makes it possible to preserve perishable foodstuffs or the like, especially composed of animal or vegetable raw materials, so that only the inner cells are in a non-frozen state. The above-mentioned slow cooling treatment performed at a gradual cooling rate of 0.01-0.5°C/hour may be combined with rapid freezing treatment, such as rapid freezing treatment [food or the like] from subfreezing supercooled state to -18°C or lower, This facilitates freezing of the extracellular fluid while making it more difficult to freeze the intracellular fluid so that the outer cells of food or the like can be frozen while the inner cells are preserved in a non-frozen state. When the present invention uses such a method, perishable foods, especially fruits, animal products, seafood or the like can maintain a high degree of freshness and quality.

This method can be beneficial to food or the like such as water, beverage (such as coffee, black tea, oolong tea, green tea, fruit juice and other frozen drinks or fruit sauce, jam, alcoholic beverage, etc.) preserved in the non-freezing zone below freezing point from the freezing point. The following quick freezing in a supercooled state, as a quick freezing method for other foods and beverages or the like. When slow cooling at a gradual cooling rate of 0.01-0.5°C/hour is combined with rapid freezing and ice nuclei (ice crystals or other ice crystal-forming substances) are added to food or the like while applying pressure, if necessary, through the side walls of the container , Vibration or friction, etc., various foods or beverages can be made into frozen products that maintain high quality, characteristics, etc. through flash freezing. Such as beer, sake, shochu, wine, whiskey and brandy), frozen tofu, sashimi, uncured ham and fruit.

The present invention can also pre-thaw the frozen food in the temperature zone below the freezing point and raise the temperature in stages with an appropriate number of times, so as to obtain high-quality thawed food. Gradually thaw the frozen food while the non-frozen components remain supercooled (1-10°C below freezing point), and then, as the temperature rises in stages, the frozen food can be thawed without damaging cells or tissues.

As discussed above, the present invention can be adapted and used as a technique for preserving and processing perishable foods (such as agricultural products, animals and marine products); pickled foods; pickled seafood; meat products; noodles; jams; fish sauces ; refined sake, beer and other liquors; vinegar, fermented soybeans, dairy products and other processed and fermented foods; animal and plant cells and other biological tissues, etc. By keeping food in non-refrigerated areas below freezing, in addition to the benefits of being able to preserve a high degree of freshness and quality of perishable foods, the above-mentioned processed and fermented foods can also achieve good aging results without any accompanying spoilage, As a result of said aging, processed and fermented foods can be improved in flavor and higher in quality.

Brief description of the drawings

Fig. 1 is a schematic diagram of the results obtained from Friding** treatment of Cynocarpus chinensis (sub-frozen storage (-2°C));

Fig. 2 is a schematic diagram of the results obtained from Friding's treatment of the round trevally (frozen storage (-0.5°C)); and

Fig. 3 is a schematic diagram of the results obtained from Friding's treatment of the round trevally (storage with ice (0°C-16°C));

Best Mode for Carrying Out the Invention

The present invention will be specifically described through the embodiments of the present invention, but the present invention is not limited to the described embodiments. Embodiment 1-in ultra-low temperature zone (sub-freezing zone) to the cold storage process of vegetables

Put the freshly harvested perishable food (lettuce) into the freezer and perform cooling treatment, quickly cool it to close to freezing point (-0.2°C), and then slowly cool it down to the lowest temperature gradually at a cooling rate of 0.1°C/hour. At freezing point, said perishable food is preserved in a non-freezing zone (-0.2--4.0° C.) below the freezing point in a non-frozen state afterwards. After the perishable food is stored in the non-freezing zone for 1 week, it is not heated rapidly but is heated gradually at a rate of 0.1°C/hour to the freezing point, and then the temperature is raised from the freezing point to 5°C. The perishable food (lettuce) which has been subjected to the cooling treatment through the above-mentioned slow cooling method and the perishable food which has not been subjected to the cooling treatment are stored in a refrigerator at 5° C. for 22 days, and then their freshness preservation conditions are checked. The results are listed in Tables 1 and 2. As can be clearly seen from Table 1, the food cooled by the above-mentioned slow cooling method has good freshness preservation, good appearance and mouthfeel, but the freshness of the food not through the cooling process obviously decreases, and it is found that its Poor appearance and construction. It can also be clearly seen from Table 2 that after cooling treatment, the residual rate of vitamin C is significantly higher.

Table 1 freshness Taste Exterior sub-freezing cooling +++ +++ +++ untreated - - - Notes: 1) Freshness: the degree to which it remains green

2) Taste: crisp

3) Appearance: degree of wilting and swelling

4) +++: Excellent; ++: Good; +: Average; -: Slightly poor; -: Poor; -: Quite poor

Table 2 Residual rate of vitamin C (%) sub-freezing cooling 95 untreated 10 Example 2 - cooling treatment of fruits and vegetables in the ultra-low temperature zone (sub-freezing zone)

Detect various perishable foods (tomatoes, onions, peas, cauliflower, potatoes, sweet potatoes, asparagus, okra, white onion, daikon (Japanese radish), persimmons, apples, lemons, cherries) in the same manner as in Example 1 , Asian pears, strawberries, figs, peaches, purple berries and apricots). Wherein, Table 3. gives the results of asparagus, okra and cauliflower. As shown by the results in Table 3, the same effect as that obtained in Example 1 was obtained for each of these foods.

table 3 Processing temperature (℃) Storage period (days) Exterior Residual rate of vitamin C (%) asparagus -1 14 +++ 90 okra -1 14 +++ 90 cauliflower -1 14 +++ 85 Note: Appearance was evaluated the same as in Table 1. Example 3-Friding treatment of Sapphire (unprocessed) in the ultra-low temperature zone (sub-freezing zone)

(1) method

The trevally used in this Embodiment 3 is a cultured trevally. Place perishable food (live trevally) in sub-freezer containers (-2°C) and freezer containers (-0.5°C) and cool them by rapid cooling to near freezing point (-1.5°C) . Then the product is slowly cooled, gradually cooled to below the freezing point with a cooling rate of 0.1°C/hour, and said perishable food is preserved in a non-freezing zone below the freezing point (-1.5--15.5 ℃). After the perishable food is stored in the non-freezing zone for 1 week, it is not heated rapidly but is heated gradually at a rate of 0.1°C/hour to the freezing point, and then the temperature is raised from the freezing point to 5°C. Then, put the perishable food (living scadmanus) cooled by the above-mentioned slow cooling method and the perishable food cooled in the ice water container (+2°C) at -2°C (sub-freezing group), -2°C Stored at 0.5°C (frozen group) and +2°C (ice water group), these samples were sensory tested by an expert group at 5, 24, 72 and 192 hours after the start of the experiment, and the K value (freshness) was determined by conventional methods. index).

(2) Results

The K value of the trevally that was cooled in the freezing container and the sub-freezing container was lower than that of the trevally in the ice water container, and these values were produced under various storage temperatures and with the lapse of storage days The change was small, meaning that the distance between these values and the ice-water chilled value widened, making the difference in freshness more pronounced. These results can be seen in Figures 1-3. At the same time, the sensory test proved that the samples in the ultra-low temperature treatment group were fresher and of better quality than those in the ice water treatment group.

The Friding treatment of various types of seafood at ultra-low temperature was also studied in the same manner as in Example 3, and finally almost the same results were produced. Subfrozen preservation and ripening of embodiment 4-leaf onion (leaf onion)

Put the green onion into the cold room and carry out the cooling treatment, quickly cool it to 0°C, then slowly cool it, gradually cool it to the freezing point of -0.8°C at a cooling rate of 0.1°C/hour, and then make the perishable Food is stored in a non-frozen state in a non-frozen area below the freezing point (-0.8--0.2°C). After the perishable food has been stored for 2 weeks in said non-freezing zone, it is gradually warmed to freezing point, and then the temperature is raised from freezing point to room temperature.

The observation of the state after 2 weeks found that when the vitamin C content of the refrigerated group (preserved at 5°C, the control group) was 6.2 mg%, the vitamin C content of the cooled sample was 27 mg%, and when the appearance of the refrigerated sample appeared While some samples rotted and wrinkled, the chilled samples remained as fresh as the day they were picked, resulting in sweeter and more flavorful leafy shallots with a good texture in the mouth.

The sugar content of the green onions before cooling treatment was 2.0%, while the sugar content of the green onions in the cold storage group dropped to 1.2% after 2 weeks, and the sugar content of the samples in the cooling treatment group rose to 3.3%. Determination of the content of free amino acids found that the content of sweet free amino acids (aspartic acid, threonine, glycine and glutamic acid) increased, while the content of bitter amino acids (valine, isoleucine and lysine) decreased, so that Onions taste like winter crops. As mentioned above, when shallots are preserved under the subfreezing zone, the preserved freshness is high and the flavor of winter crops is obtained. Preservation and ripening of embodiment 5-tuna

Put the tuna fillets in the freezer and quickly cool them down to -0.5°C, then slowly cool them down at a cooling rate of 0.1°C/hour from -0.5°C to freezing point, and then cool them below freezing point (-1.7°C) Store in a non-freezing area (-2.5--3.5°C) for 1 week. After 1 week of storage in this non-freezing area, its temperature was gradually raised to freezing point, and then the temperature was raised to 5°C. Table 4 and Table 5 represent the measurement results of freshness preservation and ripening effect of tuna after cooling treatment. Compared with the control group (former) stored at 5°C, the K value (freshness index) and sweet amino acid content of the cooled tuna were higher.

Table 4 - Tuna Preservation K value (%) start 3 days 5 days 7 days Control group tuna (stored at 5°C) cooled tuna 4.1 19.25.3 27.46.1 39.07.4 Table 5 - Observing the ripening effect of tuna from the viewpoint of free amino acid content (the third day) Content of free amino acids (%) aspartic acid glutamic acid Cooled treated tuna of control group tuna (stored at 5°C) before treatment 1.31.22.2 7.35.411.5 The storage and ripening of embodiment 6-fermented soybean

The washed and soaked rough soybeans are pressure-cooked, soybean fermentation bacteria are added, and then the soybeans are fermented at 40-50°C. The obtained fermented soybeans were rapidly cooled to -2.5°C, then gradually cooled to a freezing point of -3.1°C at a rate of 0.08°C/hour, and then stored and matured in a non-freezing zone of -4.0°C to 4.5°C below freezing point for 10 sky. After that, the temperature is gradually raised to freezing point, and then raised to 3°C, the peculiar smell of fermented soybeans is reduced, and the product has more flavor. Table 6 shows the analysis results of fermented soybean components.

Table 6 Element Chilled fermented soybeans Ordinary Fermented Soybeans insoluble protein 30.2% 11.3% Free amino acids 6.3% 2.1% ammonia 3.4% 12.0%

From the analytical results in Table 6, it can be clearly seen that the cooling treatment increased the content of free amino acids and decreased the content of ammonia. Embodiment 7-cooling treatment of drinking water in ultra-low temperature zone (sub-freezing zone)

Drinking water is put into the cold room and cooled, it is rapidly cooled to close to the freezing point (-2.8°C), and then slowly cooled to gradually drop to the freezing point at a cooling rate of 0.2°C/hour under six setting conditions : exactly as it is, pressurization of 0.1-10kg/cm ² , far-infrared radiation of 30-100μm, microwave radiation of 500-5000MHz, appropriate amount of electrostatic radiation and vibration at 1-20KHz. The drinking water is stored in a non-freezing state in a non-freezing zone (-2.8--17.0° C.) below the freezing point to produce non-freezing drinking water below the freezing point. It was found that with the addition of the steps of applying pressure, light radiation and vibration, it was easier and more stable to [introduce water] into the non-freezing region than without said steps. Embodiment 8-cooling treatment of beverage (beer) in ultra-low temperature zone (sub-freezing zone)

Put the beverage (beer) into the cold room and carry out cooling treatment, quickly cool it to close to the freezing point (-2.8°C), and then slowly cool it down, at a cooling rate of 0.01-0.5°C/hour under six setting conditions Gradually drop to freezing point: exactly as it is, pressurize 0.1-10kg/cm ² , far-infrared radiation 30-100μm, microwave radiation 500-5000MHz, appropriate amount of electrostatic radiation and vibration at 1-20KHz. The beverage (beer) is preserved in a non-frozen state in a non-freezing zone (-2.8--17.0° C.) below the freezing point to produce a non-frozen beverage (beer) below the freezing point. It was found that with the addition of the steps of applying pressure, light radiation and vibration, it was easier and more stable to [introduce the beverage] into the non-freezing zone than without said steps. Embodiment 9-cooling treatment of meat products (sliced beef) in ultra-low temperature zone (sub-freezing zone)

Put the beef slices wrapped in the packaging material made of Japanese paper into the refrigerator and carry out cooling treatment, rapid cooling treatment to -0.5°C, and then slow cooling treatment, gradually drop to freezing point at a cooling rate of 0.1°C/hour and- Between 0.5°C, and then keep the perishable food in a non-frozen area below freezing point (-1.7--18.0°C) in a non-frozen state for 1 week to obtain non-frozen beef products below freezing point (-1.7°C) . After the product has been stored in this non-freezing area for 1 week, its temperature is gradually raised to freezing point and then to 5°C. It was found that the meat products thus obtained achieve a higher degree of curing than conventional products. The results are about the same when the food is covered or wrapped with polyethylene, glycerin, glycoprotein, gelatin, etc. Example 10 - cooling treatment of fruit or similar in ultra-low temperature zone (sub-freezing zone)

The fruit (Asian pear) was placed in the freezer and subjected to a rapid cooling process to 0°C, followed by a slow cooling process at a cooling rate of 0.1°C/hour to a freezing point of -1.5°C, after which the perishable Store food in a non-freezing zone below freezing point -2.2--15.0°C. [Fruit] After being stored in this non-freezing area for 2 weeks and entering a supercooled state, it is frozen below -18°C, causing free water to move from the intracellular fluid to the extracellular fluid, causing the extracellular fluid to dilute while the intracellular fluid Concentration, making it easier to freeze the extracellular fluid and, conversely, more difficult to freeze the intracellular fluid, leads to novel fruit preparations in which the intracellular fluid is preserved in a non-frozen state.

Beverages (alcoholic beverages, coffee, soft drinks, etc.), sashimi, uncured ham, fruit, tofu, etc. were similarly cooled using the above cooling treatment method, and the following results were obtained. For beverages, when they are frozen from a supercooled state of 1-10°C below freezing point, fine ice crystals form immediately, resulting in new types of refreshing, refreshing juice-like foods that melt just right in the mouth. Likewise, in the case of sashimi, uncured ham and fruit, the chilled flavor and texture of the ice crystals are important conditions for them when they are frozen from a supercooled state 3-10°C below freezing, and the resulting product The product obtained by the conventional method is better in quality, with finer ice crystals, better melting in the mouth and milder flavor. Also, the quality of preservation when these products are thawed is higher. When frozen tofu (called Takano tofu in the Kansai area), firm tofu (firm tofu) enters a supercooled state close to 10°C below freezing point through a slow cooling process, ice nuclei (ice crystals) are added, and then the tofu is frozen to freeze the protein and denatured so that it forms a spongy form, after which (in the conventional method, the tofu is flash frozen to around -20°C and then stored refrigerated for about 3 weeks) the tofu is thawed, drained and dried. The frozen tofu obtained in this way is fine and has a fairly good structure and flavor.

Industrial Applicability

As discussed in detail above, the present invention is a method for long-term preservation of perishable foods or the like (such as vegetables, fruits, meat and seafood) in a non-frozen state in a subfreezing non-refrigerated area, and the preservation is easy The method of perishable food or the like is characterized in that a rapid cooling treatment is performed, that is, the perishable food or the like is cooled relatively rapidly (within 1-30 minutes or several hours) from room temperature to close to its freezing point, followed by a slow cooling treatment, That is, [food] is cooled to below the freezing point at a gradual cooling rate of 0.01-0.5°C/hour. The present invention produces the following advantages.

(1) Perishable foods such as vegetables, fruits, seafood, and the like can be preserved with a high degree of freshness.

(2) The unavoidable decrease in freshness of perishable foods or the like immediately after harvesting thereof can be effectively suppressed.

(3) When the perishable food or the like processed by the preservation method of the present invention is then processed in a conventional low-temperature distribution and transportation mode, it can provide consumers with high freshness and high quality without any post-harvest freshness. Perishable food or similar with immediate fall effect.

(4) The perishable food or the like treated by the preservation method of the present invention can last for a long time during consumption, preventing rapid deterioration which is common in conventional products at the consumption stage.

(5) New types of frozen products that were not available before can be manufactured.

Claims (8)

1. A method for preserving non-frozen food in a temperature zone below the freezing point of the food, which includes rapidly cooling the food to close to the freezing point, and then slowly cooling the food below the freezing point at a gradual cooling rate of 0.01-0.5°C/hour, so as to keep the food below the freezing point The food is stored in a non-frozen state in a low temperature zone 0.1-10°C lower than the freezing point. 2. The method for preserving food in a non-frozen state in a temperature zone below the freezing point of the food according to claim 1, wherein the method includes raising the temperature of the food to the freezing point or 0.5-1.0°C above the freezing point at a predetermined time in a predetermined cycle . 3. The method for raising the temperature of food stored in a non-freezing zone below the freezing point in a non-frozen state to room temperature in a non-frozen state according to claim 1, comprising raising the temperature of the food at a gradual temperature increase rate of 0.01-0.5°C/hour to Close to freezing, then bring the temperature of the food from freezing to room temperature. 4. A method of producing a food that is preserved below the freezing point of the food in a non-frozen state by the method defined in claim 1, wherein the food is cooled by slow cooling treatment at a gradual cooling rate of 0.01-0.5°C/hour. 5. The method for preserving food in a non-frozen state in a temperature zone below the freezing point of the food according to claim 1, which includes (1) irradiating the food with far-infrared rays, microwaves or static electricity at a predetermined period and at a predetermined time, or (2) heating the food Vibrate the food in the temperature zone above the failure point, or (1) and (2) to stabilize the supercooled state below the freezing point. 6. The method for preserving non-frozen food in a temperature zone below the freezing point of the food according to claim 1, wherein the packaged or covered food is cooled in a specific low temperature zone 0.1-10°C lower than the freezing point, wherein the packaging is made of synthetic resin , paper or biological material; or packaging material coated with glycerin as an ice nucleation inhibitor, glycoprotein or gelatin as an ice crystal growth inhibitor; or a cover film of these substances. 7. A method of preserving food of animal or vegetable origin below the freezing point of the food, in which only the internal cells are in a non-frozen state, which comprises preparing the food stored in the non-frozen state by the method defined in claim 1, and by The following quick freezing process performs quick freezing to destroy the supercooled state of the food, causing the outer cells of the food to freeze while the inner cells are in a non-frozen state. 8. A method for producing a frozen food from a food stored in a non-frozen state in a non-freezing zone below the freezing point, which includes preparing the food stored in a non-frozen state by the method defined in claim 1, and performing a quick freezing process below the freezing point The supercooled state of quick-frozen food to obtain frozen food.

Images