WO2004047542A1 - Method for producing a snack product which is fat-free or low in fat - Google Patents

Abstract

The invention relates to a method, especially a continuous method, for producing snack products which are fat-free or low in fat, such as potato chips, Jerusalem artichoke chips, other vegetable chips, or pasty snacks. According to the inventive method, the snack product is first optionally blanched, cooked and dried by means of a combined superheated steam/microwave treatment, and then optionally subjected to a final drying. During the course of the method, a mixture of spices and/or a defined quantity of fat can be added, for example as a flavouring agent.

Description

METHOD FOR PRODUCING A FAT-FREE OR LOW-FAT SNACK PRODUCTS

The invention relates to a method for producing fat-free or extremely low-fat snack products, such as potato chips, chips from Jerusalem artichoke or from other vegetable tubers, but also from dough. The invention relates primarily to the production of fat-free and low-fat potato chips, but can also be used for the production of other snack products, sometimes with the omission of individual production steps.

Known processes for the production of snack products are drying processes, such as hot air drying, microwave drying, radiation drying, freeze drying, superheated steam drying, etc., which enable the snack product to be dehydrated without or with the addition of fat. Various deep-frying processes using fat or fat substitutes are also known.

The disadvantage of the known drying processes, which do not require the use of fats, is that the drying of the individual pieces does not take place uniformly, but individual areas are already largely dehydrated, while other areas still have a higher moisture content. This results in the need to accept longer cooking times at lower temperatures in order to achieve even drying without partial overheating of the food.

Another disadvantage of the known methods of microwave drying is the fact that the end product has a certain taste of raw potatoes. Another disadvantage of pure microwave drying is that towards the end of the drying phase, when the moisture content of the material to be dried falls below a certain value, but especially when the desired final moisture content of about 0.5 to 3% by weight of moisture content is reached, the material to be dried partially overheats while the desired puffing effect, which gives the product a pleasant mouthfeel and an appearance indistinguishable from conventionally fried chips, has not yet taken place, i.e. either, when the drying phase in the microwave ends with a higher moisture content, the desired consistency is sometimes not achieved , or, in the case of a higher degree of drying due to the partial drying of the material occurring high temperatures (intensive browning) the formation of acrylamide, a reaction product containing starch or carbohydrates, which is suspected of being extremely harmful to health, is massively promoted.

The disadvantage of the deep-frying process is that the end product has a high fat content due to the fat intake (approx. 20% by weight for light chips or above, up to around 50% by weight for various types), and on the other hand the frying temperature for reasons of process manageability cannot be reduced below a value that prevents the formation of acrylamide or at least reduces it to a level that is harmless to health. Since, according to the current state of knowledge, the formation of acrylamide is directly proportional to the temperature and dwell time of the goods and the starch escaping during frying remains a multiple of the frying time of a single batch in frying fat, it is obvious that acrylamide accumulates in the frying fat, which the fat intake of the fried food later also leads to high acrylamide values in the end product, especially towards the end of the use of one and the same amount of fat.

It is also an economic disadvantage of deep-frying processes that the deep-frying fat has to be disposed of after use, or that it also makes up an economically relevant part of the production costs.

From US 5,952,026 A from 1999 it is known to produce fat-free potato chips using microwave drying with subsequent subsequent drying with hot air or infrared. The problem of overheating individual areas that are already largely dehydrated is solved here by a time-consuming sequence of heating and cooling phases, which makes the process uneconomical.

The US 5,292,540 A discloses the production of a potato chip product by heating and thus partially drying for a few minutes at high temperatures (up to 500 ° Fahrenheit, corresponding to 260 ° C) and then final drying under the influence of microwaves for a few minutes. The description (column 3, lines 28ff) also states that instead of heating (baking) steaming can take place. For the heating step, the description also states that its end can alternately overlap the beginning of the microwave treatment, while an intermediate stage between the end of the steaming and the beginning of the microwave treatment with convection heating to dry the potato slices is proposed for the steaming process.

No. 5,718,935 A from the same inventor describes essentially the same method, but not in as much detail, and only speaks of heating and subsequent treatment with a microwave.

EP 0 482 709 A1 relates to the production of a product from dough, preferably potato dough, the plate-like shaping of the dough and the subsequent “cooking” by means of hot air or superheated steam.

No. 5,392,698 A describes the production of fat-free products from potatoes, vegetables and the like, the method comprising washing, cutting, predrying, irradiation with high-energy microwaves, subsequent seasoning and finally finishing with low-energy microwaves. In this process too, similar to the first one, the product is pre-dried, which means that when it is subsequently treated with the microwave, it tends to become tough and skinny and therefore does not correspond to the usual and desired taste and bite of chips made in hot fat have been.

Finally, US Pat. No. 4,283,425 A applies protein to potato chips in order to achieve an improved surface structure when attacking and biting. According to the description, a thin layer of oil can be applied to this surface and then the slice is placed under the influence of Microwave beams completed.

From this overview of the prior art it can be seen that all processes which run in several stages attempt to shorten the time of application of the microwave radiation by pre-drying. One reason for this is probably the large difference in costs for the application of energy using hot air on the one hand and microwaves on the other hand and also the fact that the formation of so-called hot spots with a tendency to burn or charring of the product cannot be ruled out if the microwaves are used only.

In this context, it should be noted that if there is no water in the product, the microwave stimulates the other dipolar molecules in the product to vibrate and thus transfers the energy directly into the product, which leads to this overheating. In addition, as mentioned above, the popping of the individual cells of the product is becoming increasingly unlikely or rare as a result of the procedure in the cited documents, and the product is therefore increasingly poor in organoleptic terms.

In contrast, the invention proposes that the cut raw material as it is, or in a preferred embodiment according to a sub-claim in a blanched state, be subjected to a combined microwave and superheated steam treatment. The reason for this is that only when the initial moisture level is high and even, by boiling the water content of the potato slices quickly and internally, the popping (puffing) occurs in a manner comparable to that of a deep-frying process, evenly distributed over the potato slice or the respective good, resulting in a texture and a leads to tender crispiness, as it is known from fried potato chips.

The simultaneous introduction of hot steam, or simply the presence of this steam, in the cooking space of the microwave oven keeps the surface temperature of the chips at the maximum temperature of the hot steam, while this does not involve the introduction of hot steam towards the end of the microwave process, however, when the desired popping has occurred is evenly completed, in places can rise well above 200 ° C. This undesirable excessive heating in turn leads to an undesirable formation of acrylamide and to partial, excessive browning, even charring.

Contrary to the teaching of US Pat. No. 5,292,540, the presence of superheated steam is particularly noticeable towards the end of the drying process in the microwave essential because then the cooling of the potato slices due to the steam coming out of the potato slices is no longer possible due to a lack of subsequent steam, but also couple other components of the potato slices to the microwave and thus overheat the potato slices. A premature termination of the microwave process before local overheating leads to a qualitatively significantly poorer result, since the popping (funging) has only partially occurred because the potato slices do not evaporate sufficiently (edge zone / middle, inhomogeneous structure of the potato meat, differences in thickness, etc.) parts of a slice or thinner slices are already dry and start to overheat while others have not yet dried sufficiently. After the subsequent final drying, areas which have not been sufficiently popped and dried in the microwave have a hard, parchment-like appearance which is not desired.

The steam (introduced) according to the invention thus cools the areas of the surface that have already dried substantially, but on the other hand does not prevent further drying of the still moist areas of the material.

Popping or puffing is understood in the description and the claims to be the formation of a vesicle-like surface as it also occurs during deep-frying. A cross section through a finished chip shows many inner and superficial bubbles with very thin webs, such as foam. This results in a crunchy, very crispy bite, without hard spots or sharp breaking edges. Inadequately popped chips dry out hard in the final drying process and break in the mouth with sharp edges.

The organoleptic properties of the product produced according to the invention are therefore highly superior to those produced by the process according to US Pat. No. 5,292,540 A.

The simultaneous treatment with hot steam and microwave radiation now specifies a minimum humidity and a maximum temperature, or heating the already largely dry chips or parts of the chips to the temperature of the introduced superheated steam leads to microwave-related heating kept significantly higher than the temperature of the superheated steam and thus on the one hand secured the popping, on the other hand prevented overheating and charring and thereby in particular avoided or at least greatly reduced the formation of acrylamide.

It should be pointed out that the treatment with microwave radiation does not take place in superheated steam or hot steam in the technical sense as with steam generators, but in strongly humidified air. The steam used can be wet steam in the technical sense, it is essential that it is at least so hot that it does not cool the material brought into the treatment room to the extent that the popping is prevented. The temperature of the steam is limited upwards by the risk of acrylamide formation, although any cooling of the steam during its introduction and relaxation can of course be taken into account. The appropriate parameters can easily be determined by a person skilled in the art with knowledge of the invention and the material to be treated by a few experiments.

The invention has for its object to provide a method for the production of fat-free or provided with a defined fat snack products that enables particularly short and therefore economically interesting production times, in particular in a continuous process, without partial overheating of the food due to the effects of high drying temperatures or energy densities cause. In particular, the production of acrylamide, a neurotoxic or carcinogenic substance that occurs according to the latest WHO studies, particularly in potato chips or all neurotoxic or carcinogenic substances that are exposed to starchy or carbohydrate foods when they are produced at high temperatures (above approx. 160 ° C), is said to be through a manufacturing process , which takes place over the entire course at temperatures below 160 ° C., preferably below 130 ° C. Furthermore, the consistency and taste of fried products should be as similar as possible, production should be possible without the additional addition of fats or fat substitutes, or it should be possible to set a defined fat content starting with the initial value of the raw material's own fat content and the snack product should be as low in calories as possible. According to the invention, this is achieved in that the food to be cooked is introduced into the cooking space of a microwave oven, preferably with a high energy density, and that the cooking space is simultaneously subjected to hot steam at a temperature between 100 ° C.-160 ° until a residual moisture of the food of 2 to 10% by weight is reached, and that the desired final moisture content of the goods of less than 0.5 to three percent by weight is then optionally achieved by drying with hot air, cold air, infrared or vacuum drying.

When using the method on food other than dough, for example on raw potato slices 0.5 to 3 mm thick, the food is first blanched for 30 seconds to 4 minutes in water at temperatures from 70 to 100 ° C. and then placed in the cooking space of the microwave oven.

An additional bath before the blanching bath, which has a temperature of 10 to 60 ° C and is used for the additional flushing out of starch and sugar, has also proven to be advantageous for reduced acrylamide formation in the end product. The duration of the raw food to be cooked in this washout bath can be from less than a minute to several, for example 10, hours. Here, a duration must be selected in the production that leads to the desired result in terms of taste, since water-soluble ingredients can also be washed out with a longer residence time, which make a significant contribution to the taste of the end product. This can be desirable for various end products, since the chips themselves become practically tasteless and take on the taste of the seasonings applied if the dwell times are long. In any case, with short dwell times, this bath serves to wash away superficial starch (in the case of potato slices).

In the case of tuber vegetables, especially potatoes, the blanching process at the beginning of the process also causes starch to be washed out of the slices, thus reducing the calorie content of the snack product. Furthermore, a reduced starch content also results in a reduced acrylamide formation and finally the blanching process also has the desired taste effects on the end product, namely it takes away the taste of raw potatoes that occurs when only that other process steps are applied. Furthermore, with a suitable choice of temperature and residence time, enzymatic reactions are prevented.

Salt and other condiments that influence the taste of the end product can be added to the blanching bath. In particular, the addition of salt leads to a different behavior of the food in the microwave oven, since the changed electrical conductivity of the water in the food changes, in particular improves, the energy absorption of the microwave radiation. This in turn influences the type and shape of the bubbles in the food to be cooked and thus represents a parameter in order to achieve an end product that is as similar as possible to fried products in texture, appearance and mouthfeel. A defined amount of fat can also be emulsified in the blanching bath, which leads to a very thin but uniform film of fat on the food.

Another possibility of blanching is that raw potato or vegetable slices are pre-cooked in steam at temperatures of 70 ° C to 160 ° C for a period of 30 seconds to 10 minutes before the combined microwave / superheated steam drying.

The well-known principle of microwave drying is based on the fact that the individual molecules of dipolar media, such as water, are constantly reversed by an alternating electrical field and thus the resulting friction generates heat that allows the water content to evaporate from the inside. As a result, with the appropriate field strength, vapor bubbles form within seconds within the individual snack pieces, which cause the product to "puff" as if a blowing agent, such as baking powder, were present in a cake. In the case of potatoes - And other chips and also many other snack products, this is a desired effect because it has the effect that the mouthfeel and the appearance are equivalent to the conventionally fried chips, or that no blowing agent is required to achieve an airy end product the temperature of the material to be dried is limited to the evaporation temperature of water. Towards the end of the drying phase, however, due to the inevitably inhomogeneous material consistency and the finite piece size, i.e. central and peripheral zones with different drying times, there is a risk of regional overheating, which can lead to partial combustion of the material to be dried, while other areas on the same piece still have a high moisture content exhibit. To counteract this effect and to keep the surface of the items to be dried at a uniform, defined temperature, hot steam at temperatures between 100 ° C and 160 ° C is introduced into the cooking chamber, which in this case is used in particular to cool the surface. This results in a very uniform, high through-drying, without the risk of regional overheating, using the intensive and fast microwave drying. Browning of the product can also be adjusted uniformly via the appropriate choice of the temperature of the hot steam, or, depending on the choice of process parameters, can also be avoided entirely.

Regardless of the amount of moisture escaping from the food, there is a high relative humidity in the cooking chamber itself, which additionally heats the surface of the food at the beginning of the microwave process and thus reduces the necessary use of microwave energy to evaporate the water content of the food, which also has economic advantages, but towards the end of the microwave drying process, however, cools the surface of the already largely dry food, which has been heated to a great extent, and from which hardly any moisture escapes, and thus prevents the food from overheating.

Overheating of the food to be cooked, although there is little or no water left in the food to be cooked, occurs when the microwave is dried, even if other components of the food to be cooked are dipolar in character but do not evaporate. This is the case, for example, with potatoes, so that they can even set fire to them if they are irradiated with microwaves over a certain degree of dehydration. In any case, areas are created within a potato slice that are already largely dehydrated and whose temperature rises well above 100 ° C, while other areas of the same potato slice still have a higher degree of moisture. Another way of producing this high air humidity towards the end of the microwave drying process, where the food itself hardly evaporates any more, is to bring open containers with a sufficient amount of water into the microwave area in addition to the food, which is caused by the microwave radiation is brought to a boil. This also creates high relative air humidity during the entire drying process and leads to good results regarding the uniformity of the drying process. For economic considerations, however, this method should hardly be used for large-scale production, since relatively expensive MW energy has to be used to generate steam, but should be mentioned for the sake of completeness.

In order to reduce the formation of acrylamide as much as possible, the lowest possible degree of browning should also be aimed for, which in the method according to the invention can be achieved by a suitable choice of the temperature of the injected hot steam down to

100 ° C can be achieved (comparable to the above-mentioned co-heating of additional water by the MW) without the risk of losing the

Controllability of the process exists. The drying is very extensive and even with a maximum and also uniform puffing effect. An investigation by the NAFU, Berlin has shown that, without the whole

Having already optimized the production process with regard to acrylamide formation

Application of the method according to the invention values of just over 200

Micrograms of acrylamide kg of finished potato chips are available, in contrast to up to 3000 micrograms / kg when frying.

In addition, a fat content of approximately 0.3 g / 100 g and a calorie content of 350 kcal / 100 g were found in the potato chips produced using the method according to the invention. In contrast to the deep-frying process, the process also offers the possibility of completely avoiding the formation of acrylamide, since the process parameters can be adapted within the specified range of variation without losing process controllability. Another advantageous method to achieve puffing of the food to be cooked at a low thermal load is a combination of microwave, steam supply and pressure reduction, since the boiling temperature of the water in the food to be cooked drops as the ambient pressure drops and the formation of acrylamide is also completely prevented.

After the combined hot steam microwave drying, the product can, if necessary, be subjected to a final drying to the desired residual moisture, for example by means of hot air, cold air, infrared or vacuum drying.

Cold air and vacuum drying are particularly advantageous with regard to low acrylamide pollution, because both process steps do not allow any further formation of acrylamide, although in the former case there is a certain disadvantage in the longer drying times. Vacuum drying requires a higher outlay on system costs, but drastically reduces drying times. In this case, the drying can be supported by heating the material to be dried by means of heated support surfaces, infrared or by means of microwave radiation with a significantly lower energy density than in the case of main drying.

If a certain browning is desired for reasons of the appearance of the end product or also for taste reasons, it is advantageous to achieve this by intensive infrared radiation lasting a few seconds as the last production step, because in this case because of the short duration and the only superficial Heating the least possible further acrylamide formation has to be accepted.

It has proven to be particularly advantageous to carry out the final drying using hot air at temperatures between 100 and 170 ° C. and residence times between a few seconds and several minutes. In a preferred variant, for example, 120 ° C and 4 min dwell time lead to a result with final moisture of 1% with a very slight degree of browning, which, however, depends heavily on the ingredients of the raw product. In any case, the desired degree of browning and the final moisture content can be achieved related taste aspects, through a simple regulation even with varying quality of the starting product, standardize.

In the case of the production of the sack product potato chips or Jerusalem artichoke chips, the seasoning is carried out on the one hand in the initial blanching bath by pre-seasoning with water-soluble seasonings or before the microwave drying process with temperature-resistant components of the seasoning, which should remain largely adherent on the surface, or as usual, after all drying steps, for example in a seasoning drum.

Likewise, either in the blanching bath and / or before or after the microwave drying process, a defined amount of fat can be added, which on the one hand acts as a flavor carrier and on the other hand also makes it possible, as the last step in the production process, to add a well-adhering seasoning with seasoning agents that do not have any thermal stress Loss of taste may be exposed to the product. Without an adhesion promoter, such as the fat in this case, no other, firm seasoning would otherwise stick.

However, the amount of substances that are required for the adhesion promotion and are applied only on the surface is only a few percent to fractions of percent of the total mass, depending on the grain size and physical properties of these substances.

This adhesive effect for the application of spices after the temperature-intensive drying process can also be achieved by seasoning with fatty spices after the blanching process and before microwave / superheated steam drying, since this spills out of fatty spices at the process temperature achieved and is also superficially close to the spice grains spreads. Other spices with a correspondingly small grain size then adhere to this wafer-thin surface fat film.

A number of snack or baked products, in particular potato chips, Jerusalem artichoke chips, stacking chips and other snack products, also made from dough, are produced that fully meet the usual requirements for taste and consistency and still have a fat content that goes down to zero beyond the natural fat content of the raw products, as well as foods that contain starch and carbohydrates through baking and deep-frying processes exposure to acrylamide to a much lesser extent than before, down to no exposure.

Particularly in the case of potato chips, this process is a process that can be set with many parameters, which is a process that is convincing in terms of taste and comparable to conventional processes, particularly through the combination of a blanching process, microwave drying that is thermally controlled by the introduction of hot steam and subsequent final drying to the desired residual moisture The process produces a very similar end product, but its health aspects far outperform commercially available potato chips, especially with regard to fat content, calorific value and acrylamide pollution.

Example of a continuous production of fat-free potato chips:

Potatoes of the corresponding type are washed in a known manner and then peeled or left unpeeled, then fed to one or more cutting devices, where they are cut into slices of 0.5 to 3 mm in thickness. Immediately after cutting, the potato slices are individually placed on a conveyor belt, for example consisting of a Teflon grid, and first by a wash-out bath at a temperature of below 60 ° C, in which at least the starch that emerges on the surface is washed off, then by a bath with water between 70 and 100 ° C, possibly mixed with spices, guided, for example, by fixing between two grid tracks.

The surface can then be pre-dried, for example in an air stream, and then, depending on the taste, a seasoning can also take place which adheres to the surface of the chips, which is still slightly damp. After that, the conveyor belt (s) are conveyed through a tunnel with intensive microwave radiation led by blowing hot steam. Before or after the milk drying, a precisely defined amount of fat (between 0% and about 30% by weight) can be applied, which serves to influence the taste and / or as an adhesion promoter for seasoning after all drying steps.

The potato slices, which had already largely dried and puffed after MW drying, no longer stick and are transferred from the continuous assembly line to a batch operation or a slower assembly line, where they are poured much denser than before into a continuous hot air drying device. After the final drying, depending on the taste, a seasoning can be carried out in a seasoning drum with spices that must not be exposed to temperature. Then the chips come for final inspection and packaging.

In another advantageous variant, the final drying is achieved by vacuum drying instead of hot air drying.

In a further variant, final drying and browning can also be achieved by continuously moving the conveyor belts through an area with radiant heat.

In the production of snack products from doughs, the area up to the blanching bath is omitted, the seasoned dough, possibly pre-cooked in parts of its components, is applied in portions to suitable conveyor belts and fed to the combined microwave / superheated steam oven. Depending on the desired final moisture content of the finished snack product, a vacuum hot air or radiation dryer can also be connected here.

This process offers a wide range of process parameters that can be varied over a wide range, particularly for the production of fat-free or low-fat potato chips without or with minimal acrylamide contamination, to find settings that lead to an end product that is optically and tastefully (appearance, texture, taste , Aftertaste, mouthfeel when chewing, melting when saliva is ingested, leaving when swallowing, etc.) is practically indistinguishable from conventional, fried potato chips.

In addition, the process described offers the possibility of choosing fats that cannot be used in a deep-frying process because they do not have the necessary temperature resistance.

On the one hand, this results in possible health benefits for consumers, but also interesting, completely new flavors through the use of aromatic oils (e.g. olive oil, peanut oil, pumpkin seed oil, etc.), with only a few% addition, which cannot be produced with conventional frying processes ,

The term "fat-free" is understood in the description and the claims to mean that no fat is added to the snack product in the course of its production: optional blanching, drying in a microwave oven with hot steam and, if appropriate, drying, so that the end product is only used before the process in The term “low-fat” or “low fat content” or “defined fat content” is to be understood in the same way: the amount of fat deliberately added for the reasons mentioned above in the course of the process according to the invention is “defined” or "low".

The invention is not limited to the example described, but can be modified in various ways. It is therefore possible to carry out them in a so-called "batch" operation, especially if only small quantities of snacks are to be produced for immediate consumption. The duration and the combination of the individual optional process steps depends on the desired final state of the product and the available initial material (fresh potatoes or storage potatoes, available varieties and sizes, etc.) and can easily be determined by a person skilled in the art in the field of snacks with knowledge of the invention. The starch can be extracted from the blanching water and / or prewash water which results in a sought-after raw material which, in many cases, is desired in the end product only in small quantities or not at all.

A key point of the invention is, among other things, the cooling effect of a highly moisture-saturated atmosphere in the area of extensive drying of the food. This cooling effect is created with targeted measures where (or if) the moisture, which is only low or does not escape from the material, no longer ensures cooling. In addition, there are the other effects which, thanks to the diverse, independently adjustable parameters of the process, only make it possible to produce an end product that is practically indistinguishable from conventionally fried chips.

Such a measure is also, in particular in the case of continuous processes, to direct the steam emerging from the material to be dried, in particular at the beginning of the treatment, to the end of the cooking and drying process by means of microwave radiation in order to achieve the cooling effect according to the invention. In this sense, for the respective process state under consideration, the term: “additional steam means any steam that does not emerge from the material to be dried in this process state of the drying process.

The description and the claims mostly refer to “cooking” or “food to be cooked”, although strictly speaking it is a kind of dehydration of the food.

Claims

claims: 1) Process for the production of fat-free, or with a low fat content snack products such as potato chips, vegetable chips, stacking chips and other snack products from dough, by treatment with microwave radiation, characterized in that the dehydration or drying process by the simultaneous treatment of the goods with microwave radiation and superheated steam, which has temperatures of 100 ° C to 160 ° C, takes place. 2) Method according to claim 1, characterized in that raw potato or vegetable slices are blanched in water at temperatures between 70 ° C and 100 ° C for a period of 30 seconds to 4 minutes before the combined microwave / superheated steam drying. 3) Method according to claim 1, characterized in that raw potato or vegetable slices before the combined microwave / hot steam drying for a period of 30 seconds to 10 minutes in hot steam at temperatures of 70 ° C to 160 ° C can be pre-cooked. 4) Method according to claim 2 or 3, characterized in that raw potato or vegetable slices are washed in water from 10 to 60 ° C for a period of 10 seconds to 10 hours before blanching or norgare. 5) Method according to claim 2, characterized in that the blanching water is seasoned, in particular salted. 6) Method according to one of claims 1 to 5, characterized in that the snack product after the combined microwave / superheated steam drying is fed to a final drying to 0.5-3% by weight by means of vacuum drying. 7) Method according to one of claims 1 to 5, characterized in that the snack product after the combined microwave hot steam drying is fed to a final drying to 0.5-3% by weight by means of hot air drying at temperatures from 60 ° C to 170 ° C. 8) Method according to one of claims 1 to 5, characterized in that the snack product after the combined microwave / superheated steam drying is fed to a final drying to 0.5-3% by weight by means of radiation drying. 9) Method according to one of claims 1 to 8, characterized in that the snack product is mixed with fat or fatty seasoning in the course of the process. 10) Method according to claim 9, characterized in that the fat is sprayed in a defined amount. 11) Method according to claim 9, characterized in that the fat to be applied is atomized. 12) Method according to claim 9 and 2, characterized in that the fat to be applied is emulsified in the blanching bath. 13) Method according to one of the preceding claims, characterized in that the combined microwave / superheated steam drying is carried out up to a moisture content of 1.0-5% by weight of the material. 14) Method according to one of the preceding claims, characterized in that the steam is introduced into the cooking space. 15) Method according to one of the preceding claims, characterized in that, in particular in the case of continuously operated systems, the steam which is at the beginning of the cooking and drying process in the cooking space by drying the The food to be cooked is added to the food at the end of the cooking and drying process.