JPS6338185B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a method for compressing freeze-vacuum dried strips of food such as vegetables, rice, meat, and combinations thereof, wherein the dried food is dried to a lower moisture content without compression. It relates to such a process that the food product is made to have a significantly greater density and, upon addition of water, recovers approximately the same state as the broken pieces it had before compression. Freeze-drying of food products is well known for allowing food products to be stored at room temperature and for long periods of time at higher temperatures if very low moisture content is maintained during storage. If such foods are properly prepared and stored, they can be rehydrated when desired and the reconstituted foods have a quality comparable to similar unprocessed foods. Recently, food companies have
It has become highly desirable to compress freeze-dried foods so that the foods take up less space and require less material for packaging. One widely accepted method for compressing freeze-dried foods is that described in U.S. Pat. No. 3,385,715, in which the foods are
It is first freeze-dried to a low moisture content of the order of %. The freeze-dried food product is then sprayed with sufficient water to raise its moisture content to a range of about 5-13%. This is because when freeze-dried food is compressed, the food deforms plastically without collapsing, without changing its cellular composition, and the food particles adhere to each other during compression, during which water acts as a plasticizer and the food This is to minimize the possibility of it breaking into small particles. However, in order to impart the proper plasticity to a freeze-dried food product, it is necessary to spray the food product with water or an aqueous solution such as gum and then leave it for a sufficient period of time to allow the water to be evenly distributed throughout the food strips. This dispersion process takes several hours (or several days at low temperatures) to produce a high-quality freeze-dried compressed food. After compaction is made, the food product is typically freeze-vacuum dried to a sufficiently low moisture content to maintain its quality after the intended shelf life of the food product. This goes without saying that a significant degree of freeze-drying, which is itself expensive, must be repeated to remove the water that is sprayed and dispersed onto the food strips and plasticizes the food during compression. means. Furthermore, the time-consuming nature of the dispersion process requires that the drying and compaction steps be performed at different times rather than in the desired sequential process. Attempts have been made to eliminate the above-described repeated freeze-drying and associated costs by stopping the initial freeze-drying at a moisture content of about 5-13% and then compressing the incompletely freeze-dried food. . However, as is well known in the freeze-drying technical field, most of the water extracted from the food is sublimated in the center of the food strips undergoing freeze-vacuum drying, and the resulting water vapor is absorbed into the food strips. It remains frozen until removed by the action of a vacuum through the outer portion. Therefore, when freeze-vacuum drying is stopped at a moisture content of about 5-13% (on average overall) as described in the above-mentioned US patent, the outer parts of the food strips become extremely dry while the center The ice contains almost all of its original water content. If such food strips are then compressed without moisture distribution, the extremely dry outer parts may flake, and the compacted product may, for example, have poor adhesive strength and therefore be easy to flake with careful handling. Even when water is added, the particles do not return to their original size and shape, resulting in poor quality. To avoid this outcome, incompletely freeze-dried food strips are kept in a closed container at a temperature above approximately 0°C so that the moisture from the frozen core is evenly distributed throughout the strip. I was supposed to. However, such dispersion is very slow and becomes slower as the pieces get larger. In some cases, a dispersion process lasting several days was required before compaction could be accomplished without producing large amounts of powder due to crumbling of the dry outer portions of the food strips. Freeze-vacuum drying is itself a time-consuming and expensive process, and the more freeze-drying cycles required in conjunction with the compression of the freeze-dried food product, the more expensive the final product becomes. An object of the present invention is an improved method for compressing freeze-dried food strips to a relatively high density, comprising:
When water is added, the food reverts to almost the same discrete strips as before compression, and the remanufactured food is of a higher quality, comparable to the raw or cooked food from which the freeze-dried food was made. The objective is to provide a method that can be made comparable to Furthermore, a widely accepted method of compressing freeze-dried vegetables involves a prior blanching treatment to inactivate enzymes, particularly peroxidases. After blanching, these vegetables are treated with sulfite or sulfite to ensure that the product retains its color and quality for long periods of storage. In the present invention, the enzymes are inactivated during the microwave treatment after incomplete freeze-drying, so both of the above-mentioned treatments can be omitted. The sulfite treatment can be omitted due to the high product to oxygen ratio if the compressed product is hermetically sealed in a vacuum container. Compression of freeze-dried foods is accomplished as follows. The food is first partially freeze-dried (without blanching or sulfite treatment for vegetables) in strips to an average moisture content of about 8-28%, and then the partially freeze-dried food is While it is frozen, begin irradiating it with microwaves. The irradiation is at a frequency, intensity, and time such that any remaining moisture in the food product is rapidly dispersed throughout the food product to such an extent that the food product is substantially uniformly plasticized throughout. Next, the food, which has been almost uniformly plasticized by moisture, is
Compact at a preselected pressure to obtain the desired degree of compaction and density. Compression is done to about 5-50% of the volume of the food product before compression. The compressed food product is then re-dried to a moisture content of not more than 5%. The redried compressed food is hermetically sealed in a moisture-impermeable container to protect it until it is time to rehydrate it. One feature of the invention is that food products in the form of strips can be incompletely freeze-dried (the blanching and sulfite treatments carried out in the market in the case of vegetables are omitted) and then microwaved for one short time or The irradiation is performed several times at very short intervals, and the water that remains as ice in the center of the food strip after incomplete freeze-drying is rapidly vaporized and dispersed throughout the food strip. This allows compression of the food product to be done immediately after its incomplete freeze-drying. This point further emphasizes that the moisture is more evenly distributed throughout the food product after microwave irradiation than in the case of food products processed according to the prior art described in the above-mentioned US patent specification, so that the compaction can be applied throughout the food product. It is possible to operate at a somewhat higher average moisture content than in the prior art. This point results in shorter freeze-vacuum drying and lower costs. After the food is compressed, it can be re-dried by non-freezing vacuum drying, air drying, freeze-vacuum drying or other common drying methods, and if properly packaged it remains safe for long periods at room temperature or higher temperatures. A final re-dried compaction that is storable and that at a desired time after drying is reconstituted by the addition of water to approximately the same discrete strip form that the food had before the initial freeze-vacuum drying. produce food. Reconstituted food products also generally have excellent quality even after long periods of storage in a re-dried compressed state. Of course, time and temperature can have a negative effect on any form of food, but when food in the form of small pieces is processed by the method of the present invention, many remanufactured foods are produced. In terms of points, it is surprisingly similar to the original food before freezing and incomplete freeze-vacuum drying. Incomplete freeze vacuum drying is performed until the average moisture content of the food strips is reduced to about 8-28%. The type of food being processed is an important factor in determining what average moisture content to perform partial freeze drying prior to microwave irradiation and compression. The more moisture there is in the food strip, the more microwave energy will be absorbed, so during irradiation of the partially freeze-dried food, the absorption of microwave energy will not be too low. It is desirable not to reduce the moisture content of the food strips too low. It is desirable to rapidly redistribute moisture throughout the freeze-dried food strips so that compression of the food product can occur as soon as possible after incomplete freeze-drying. Furthermore, the quality of the final product is adversely affected by the prolonged contact of the food with liquid water, so if the liquid water is in contact with any part of the food for any length of time, a lot of water will remain in the food pieces. It is also desirable to avoid this. For each food strip, there is an optimal moisture content for incomplete freeze-drying. However, the method of the present invention
A wide range of moisture contents can be used with great success for any food strip. Numerous tests conducted on different types of foods have determined that the typical moisture content of incompletely freeze-dried foods is about 8-28%. In this specification, when water or moisture is expressed in %, it is % by weight unless otherwise specified. Incomplete freeze-vacuum drying of food strips may be performed using any of the common methods for freeze-vacuum dried foods. Incompletely freeze-dried food pieces can be continuously irradiated with microwave energy through a conventional microwave tunnel. A microwave scanner can be used to control the amount of microwave energy added to the food product. Food can be placed on a belt running at an adjustable speed under the microwave beam. Microwave irradiation may be performed in batches, such as by using a microwave oven. However, this is generally undesirable and costly compared to continuous irradiation.
The frequency of the microwave is adapted to the food to be treated and to the required depth of penetration and desired time to complete irradiation. Microwave irradiation and the moisture content of the food pieces are determined within approximately 1 hour after completion of incomplete freeze-drying.
Adjustment should be made such that the incompletely freeze-dried food pieces are ready to be compressed, preferably within 10 seconds to 5 minutes. This method keeps the quality of the food high. The water remaining in the frozen core after incomplete freeze-vacuum drying is released as water vapor by microwave energy, and is absorbed by the entire dry outer part of the strip, except for a small amount of water vapor that escapes from the strip. Ru. By making a proper adjustment between the amount of water in the center of the strip at the beginning of the microwave irradiation and the time and intensity of the microwave irradiation, the food strips will be able to penetrate through the microwave tunnels. Or it can be ready for compression upon exiting the oven. Excessive irradiation of the microweb food product should be avoided as this will result in high moisture loss from the strips and thermal damage to the food product. Compression of the microwave-treated food strips is approximately 7.03 Kg/cm ² in a press at room temperature (approximately 20°C) or higher if necessary.
(100 psi) to about 280 kg/cm ² (4000 psi) with a stop time of about 10 to 30 seconds. Compressed food products can be of various shapes and sizes. The inventor of the present invention has determined that from approximately 0.3 cm to approximately
It was found convenient to make a compressed rod or disc with a thickness of 1.25 cm. It has also been determined that it is desirable to compress the food to about 5-50% of the volume it has before compression. The compression ratio (defined later) is therefore about 20:1 to about 2:1. The moisture content of the incompletely freeze-dried food is adjusted to 8-28% and redistributed by microwave treatment to compress the incompletely freeze-dried food pieces as described above. When this is done, there is very little product fouling that would result in powder. The compressed food strips adhere well and are clearly smaller in volume than the original food strips. The compressed food has a moisture content of about 1-5% for stability when exiting the press and packaged in moisture-impermeable packaging, preferably about 2% for long-term storage. % or less. This can be achieved by air drying using heated air to a moisture content of about 5% or by drying in a vacuum oven in a conventional vacuum drying apparatus to a moisture content of about 3%. If redrying to a lower moisture content is desired, this can be conveniently accomplished by conventional freeze-vacuum drying equipment and methods. Of course, it is desirable to avoid excessive heating of any part of the compacted food product during redrying.
That is, if air drying is used, the air
℃ (100〓) to approximately 82.2℃ (180〓). When drying in a vacuum oven or freeze-vacuum drying, the temperature of the surface that comes into contact with the food should preferably not exceed 65.7°C (150°C) to prevent damage due to heat. The density of the compressed and redried food product is approximately 0.5-1.2 g/cc.
Redrying is the second and final drying step after compaction of the food product. After re-drying, the compressed food product is placed in a moisture-impermeable and preferably oxygen-impermeable package and hermetically sealed if it is not used immediately, which is usually the case. The package is 63.5cm
(25 inches) to 73.5 cm (29 inches) preferably sealed under vacuum. Such packaging may be a metal can, but has an innermost layer that is heat sealable, such as polyethylene, and an outermost layer that is resistant to normal damage, such as polyethylene terephthalate.
It may also be a flexible package made of multilayer films, usually comprised of aluminum foil sandwiched therebetween, which acts as an effective moisture barrier. When hermetically sealed in metal cans or multi-layered flexible packaging as described above, compressed and re-dried foods whose moisture content does not exceed 5% are typically kept at 21.1°C (70°C). ) at least 3
It can be safely stored for at least 6 months at 37.8°C (100°C) in 2017, and immediately after completing the incomplete freeze-vacuum drying, microwave irradiation, compression, and re-drying steps, the food exhibits There is no appreciable reduction in suitability. Suitability varies depending on the food and to a large extent on personal preference. However, acceptable and reproducible methods have been developed to measure quality and suitability through evaluation tests. Reconstitution of dried compressed food can be accomplished by pouring an excess amount of boiled water onto the compressed food and allowing the water and food to stand until hydration occurs. Foods thus remanufactured are ready for cooking or, in some cases, for direct consumption. Generally speaking, meat has a lot of protein, so it takes a longer time to add water than vegetables, which have a lot of hydrated carbon. Quality evaluations are made according to the invention on incompletely freeze-vacuum dried, microwave irradiated, compressed, then re-dried and hydrated and sometimes cooked food products. The food is remanufactured and tested for quality as described above. The test is done by submitting the remanufactured food products to approximately 10 trained testers, who score each food item on each rated property. Scores range from 1 to 9, with 9 indicating excellent, 1 indicating very poor, and 5 indicating limit of suitability as a food. If the average score is at least 5 for any of the attributes being evaluated. Foods are clearly compatible in terms of their properties. The overall quality is obtained by averaging the scores of different properties. The present invention is associated with particular utility with foods that either naturally take the form of strips or are often divided into strips or bite-sized pieces when served as a meal. For example, cooked rice, sliced mushrooms, diced fish, buckwheat, peas, diced green beans, diced carrots, diced beef, and other strip foods or combinations thereof. can be treated according to the invention. Importantly, these food strips
It means maintaining the cellular composition of the plant or animal from which the food is obtained or from which the plant or animal fragment exhibits universally recognized suitability for food. Foods in the form of strips, either cooked or uncooked, can be processed according to the invention, the choice being made depending on the effect of cooking on the strips and whether the hydrated food can be eaten without subsequent cooking. Depends on whether it is desirable or not. For example, once cooked, strips of meat tend to maintain their strip shape throughout the process better than vegetables, which often tend to become softer as a result of cooking, and in some cases can become crumbly and pastry. , loses its strip morphology even before compression. For example, it is desirable to treat vegetables in accordance with the present invention while they are generally uncooked. Rapid freezing is recommended to protect the composition of vegetables. According to the present invention, no blanching or sulfite treatment is required before incomplete freeze-vacuum drying, microwave treatment, compression and redrying. An example of the production of a dried, compressed, increased density food product according to the above-described principles of the invention follows.
It goes without saying that the above-mentioned and other advantages of the invention may be obtained by suitable modifications of the detailed method steps to be described below. The examples set forth below are provided for illustrative purposes and are not intended to limit the scope of the invention. In the following examples, the compression ratio refers to the volume of the incompletely freeze-vacuum-dried food strips held in the hand for placement in a container and whether they take the form of a disc or rod after compression. This is the ratio between the volume of incompletely frozen and vacuum-dried food that has been compressed without any difference in the form of Also, in the following examples, the hydration rate of a food product is the ratio of the weight of the food product after adding water to the weight of the re-dried compressed food product before adding water. Example: Fresh green peas are frozen at approximately 121°C (250°C).
Continue the platen temperature of 〓) for 2 hours and then 93.3℃
Freeze-vacuum drying was carried out in a conventional freeze-drying apparatus at a low temperature (200〓) for approximately 4 hours. The average moisture content of peas was reduced to about 17%. At this point, a significant portion of the incompletely freeze-dried peas was removed from the freeze dryer and kept frozen in a closed container until further processing. Freeze-vacuum drying of the peas remaining in the freeze dryer was continued for an additional approximately 7.5 hours to reduce the moisture content to approximately 2%. Peas thus freeze-dried were used as a comparison sample. Incompletely freeze-dried green peas with a moisture content of approximately 17% were irradiated in two parts in a conventional microwave oven. On the other hand
One was microwaved for 20 seconds and the other for 30 seconds. The microwave was approximately 2450 MHz, and the power source that provided its output was rated at 650 watts. Immediately after extracting approximately 20 g from each irradiated batch and removing it from the microwave oven, these incompletely freeze-dried peas are rectangular and have a cross-sectional area of 19.3 cm ² . Placed in the pressure press, immediately at room temperature, 105Kg/
It was compressed at a pressure of 1500 psi (cm ² ) and a dwell time of about 10-20 seconds and formed into compressed pea bars with dimensions of 2.5 cm x 7.5 cm x 1.2 cm. The compression ratio was approximately 4:1. Each of the incompletely freeze-dried and compressed pea sticks was placed in a common vacuum oven at an oven temperature of approximately 60°C (140°C).
It was further dried to a moisture content of approximately 3.8%. The density of the final compressed pea stick is 0.89
g/cc. Freeze-dried comparative peas were prepared by spraying a sufficient amount of a fine mist of water to approx.
% by weight.
After spraying, it was placed in a closed compartment at room temperature for about 0.5 hours to allow the moisture to disperse throughout. The water-dispersed comparison peas were then mixed with about 20 peas at a time.
105 kg/cm ² at room temperature in a carver-type hydraulic press similar to that used for the original sample described above.
(1500 psi) and a dwell time of approximately 10-20 seconds to form a compressed bar with dimensions similar to the original sample. The compression ratio was approximately 4:1. Each of the comparative sample pea rods was placed in the common vacuum oven used to re-dry the original sample and further dried at an oven temperature of approximately 60°C (140°C) to yield approximately 3% by weight. moisture content. The compressed peas of the original sample and the compressed peas of the comparison sample were prepared by pouring a sufficient amount of boiling water onto the compressed pea rods, and placing the rods in hot water for about 0.5 to 3 minutes. It was remade by allowing it to stand for the amount of time necessary to achieve almost complete hydration. The hydration ratio of the original sample bar was 4.3:1. The remanufactured original and comparative peas were tested by a panel of 10 experts trained to evaluate food properties. Table 1 shows the results. As explained above, in this evaluation test, each tester gives a score in the range of 1 to 9 for each item, and the scores are expressed as an average.

[Table] Processed items in microwave for 30 seconds 6.3 6.9
processing things
From the results in Table 1, it is clear that both peas of the original sample have a better texture than the comparison sample after remaking. The evaluation value of chewiness for the original sample was considerably greater than that for the comparison sample. Regarding taste, there was only a slight difference between the original samples and the comparison samples. Example A cube of raw beef thigh approximately 1.25 cm (0.5 inch) on each side is quickly frozen and then
Freeze-vacuum drying was performed at 200 °C (200 °C) for about 5 hours using a general freeze-drying apparatus. The average moisture content of beef cubes was reduced to about 28% by weight. The incompletely freeze-dried meat cubes were removed from the dryer and placed in a sealed container until further processing. A portion of the incompletely freeze-dried corner section was used as a comparison sample. Approximately 28%
The remaining sample, having a moisture content of , was subjected to microwave irradiation in a conventional microwave oven for approximately 30 seconds. The microwave was 2450 MHz and its power source was rated at 650 watts. Immediately after removal from the microwave oven, approximately 20 g of the irradiated incompletely freeze-dried meat cubes are placed in a carver-type hydraulic press with a rectangular cross section of approximately 19.3 cm ^{2 and} immediately , room temperature, approx.
Compressed at a pressure of 105Kg/cm ² (1500psi) and a rest time of about 10-20 seconds, 2.5cm x 7.5cm x 1.2
Shaped into raw beef sticks with dimensions of cm. The compression ratio was 3:1. Each of the incompletely frozen and compressed raw beef bars was placed in a conventional vacuum oven and dried to a moisture content of approximately 2.8% by weight at an oven temperature of approximately 60°C (140°C). Incompletely freeze-dried comparative beef cubes, approximately 20 g at a time, were dried at room temperature in a carver-type hydraulic press similar to that used for the original sample.
The samples were compressed at a pressure of 105 Kg/cm ² (1500 psi) and a dwell time of about 10 to 20 seconds to form compacted comparison sample meat bars of similar dimensions to the original sample. The compression ratio was 3:1. The comparative sample rods were placed in a conventional vacuum oven similar to that used to re-dry the original samples, and the oven temperature was increased to approximately 60°C.
(140〓) conditions to a final moisture content of approximately 3%. The compressed and redried beef bars and comparative samples were remade by pouring an excess amount of boiling hot water onto the bars and leaving the bars in the hot water until hydration occurred. The results confirmed that the original sample bar separated into individual beef cubes in about 5 hours, and that the cubes were completely hydrated, ie, returned to their original size and shape, after about 6 hours of soaking. The beef of the comparative sample did not separate into individual cubes even after being left in water for 6 hours. Example The process described in the example was carried out on raw carrot cubes measuring approximately 0.64 cm on each side. The temperature of the platen in the freeze dryer was approximately 51.1°C (125°C). After approximately 6 hours of freeze-drying, the moisture content of incompletely freeze-dried carrot cubes is approximately
It was 29%. A portion of the square sections were removed from the lyophilizer and processed as shown below. Freeze-drying was continued and after a total of 10 hours of freeze-drying, the moisture content of the partially frozen carrot cubes was approximately
It was 19%. A portion of this square section was removed from the freeze dryer and processed as shown below. Samples of carrot cubes were similar to those shown in the example, but samples containing 29% moisture were irradiated with microwaves for approximately 50 seconds, and samples containing 19% moisture were irradiated for approximately 60 seconds. Ta. After being irradiated for the time specified above, each sample was immediately compressed at room temperature and at a compression ratio of 12:1 to form a rod approximately the same size as the example pea. Following compression, it was re-dried in a conventional vacuum oven in the same manner as for the peas in the example to give a final moisture content of about 3%. The density of the final re-dried carrot sticks was approximately 0.53 g/cc. A portion of each batch of incompletely freeze-vacuum-dried carrot cubes, one with 29% moisture and the other with 19% moisture, was given a corresponding moisture content. It was used as a comparative sample for those containing These were compacted in a microwave without irradiation before compaction and in the same way as the original samples but without dispersing any remaining water. Comparative sample bars of compressed carrots were re-dried in the same manner as the original sample. The original sample and comparative sample bars were remanufactured using the same method as the example peas. Before microwave irradiation, carrots that were incompletely freeze-vacuum dried and compressed to a moisture content of approximately 19% were placed in hot water for 30 minutes.
After being separated, the carrot cubes were almost completely hydrated and had a good shape and size, and their edibility was also good. The carrots, which were incompletely freeze-vacuum dried and compressed to a moisture content of 29% before microwave irradiation, were placed in hot water for about 2.5 minutes to be almost completely hydrated, and the diced pieces after reconstitution were good. It had a good shape and size, and its food compatibility was good. The original sample carrot was approx.
It showed a hydration ratio of 15:1. The comparison bar took approximately 13-20 minutes to rehydrate and produced a large amount of precipitate in the rehydration water. This shows considerable damage during compression. Example In this example, the peas were processed similarly to the previous example, with the following exceptions: Approximately 93.3℃ (200〓)
After being freeze-dried for about 4.5 hours, the moisture content of incompletely freeze-dried peas was 26.8%. A portion of these peas were removed from the freeze dryer and processed as shown below. Freeze-drying was further continued and after a total of 6 hours of freeze-drying, the moisture content of the incompletely freeze-dried peas was about 12.8%. A portion of the peas was removed from the freeze dryer and processed as shown below. The pea samples were microwaved for 40 seconds in the same manner as in the example, but for each incompletely freeze-dried pea. Immediately after being irradiated for the above period, each original sample of peas was compressed at room temperature to a compression ratio of approximately 4:1 and formed into rods approximately identical to the example pea rods. After compaction, the pea rods were re-dried in a conventional vacuum oven in the same manner as the example peas to a final moisture content of approximately 3%. The final re-dried pea stick density was approximately 0.89 g/cc. A portion of each batch of incompletely freeze-dried peas, one with 26.8% moisture and the other with 12.8%
% moisture was used as a comparison sample to the corresponding moisture content. These were compressed in the same manner as the original samples, but without dispersing any remaining moisture in them, without microwave irradiation before compression. The compressed comparative peas were re-dried using the same method as the original peas. The original sample and the comparison sample pea sticks were reproduced using the same method as the example peas. Peas that were incompletely freeze-vacuum dried and compressed to a moisture content of 26.8% before microwave irradiation were almost completely hydrated by placing them in hot water for about 0.5 to 1 minute, resulting in recycled peas. exhibited good size and shape and had good edible compatibility. Peas that were incompletely freeze-vacuum dried and compressed to a moisture content of 12.8% before microwave irradiation were almost completely hydrated and reprocessed after being placed in hot water for about 2-3 minutes. The peas showed good size and shape and had good edible suitability. The original sample of peas had a hydration ratio of approximately 5:1. It took about 3 minutes to add water to the comparative sample of peas, and a large amount of precipitate was formed in the water used for adding water. This indicates that there is significant cracking during compression of the comparison sample. This is in contrast to the original sample, which retains good size and shape and has no precipitates in the recycled peas. The treatment has been shown to be very effective in allowing the compressed peas to maintain good dimensions and shape and to have less or less brittleness during compression. . The present invention can be used at a frequency of about 2450 to irradiate frozen and incompletely freeze-vacuum dried foods.
Although described in connection with an example using megahertz microwaves, other frequencies may also be used. Generally, commercially available microwave ovens and other manufactured microwave radiation equipment are limited to 2450±50 MHz or 915±25 MHz. Such a device is
The duration of microwave energy irradiation on incompletely frozen and vacuum-dried food products may be used at different powers, as will be apparent to those skilled in the art, depending on the power and the penetrating power of the microwave and thus its frequency. You can make it possible to From the results of the above-described implementation, it has been found that, across a variety of vegetables and meats, the present invention provides increased density when dried and compressed, with good strip shape, size and cell composition, and good food compatibility when hydrated. It is clear that a food product having the following properties can be obtained. When such food products are hermetically sealed in moisture-impermeable packaging, preferably under vacuum, they can last for extended periods of time, e.g.
At least 3 years at temperatures up to 21.1℃ (70〓) and at least 6 years at temperatures up to 37.8℃ (100〓)
For several months, the dried and compressed food retains the good food compatibility that it has immediately after its hydration. The present invention is particularly effective in reducing the volume and weight of a given amount of food as far as nutritional value and calories are concerned. Dried and compressed foods are
It is ready for use after being immediately hydrated by various water addition treatments. The method of the present invention is highly desirable since it removes most of the moisture and preserves the cellular composition of the food in its natural state despite compaction. It is more economical than other methods.

Claims (1)

[Claims] 1. A method for making a dry compressed food product of a material selected from the group consisting of vegetables and meat, comprising: freezing the strips of said material without blanching and sulfite treatment; incompletely freeze-vacuum drying the strips of the material to a moisture content ranging from about 8 to about 28% by weight; microwaving the partially freeze-vacuum-dried strips of the material; The irradiation is carried out at a time when the center of the strip is frozen at the beginning of the irradiation, and the irradiation is performed to inactivate oxygen and to dissipate the moisture remaining in the strip throughout the strip. and at a frequency, intensity, and time sufficient to uniformly disperse and substantially uniformly plasticize the entire strip ^;
(100 psi) to about 280 Kg/cm ² (4000 psi) and for a time sufficient to cause the strips to adhere to each other and form a compressed food; a moisture content of about 1 to about 5% by weight; re-drying the compressed food to form a re-dried compressed food with a content of; 2. In the method described in claim 1,
The method for producing a dry compressed food product, wherein the step of redrying the compressed food product is performed in a vacuum oven for drying the compressed food product. 3. In the method described in claim 1,
A method for producing a dry compressed food, wherein the step of redrying the compressed food is performed by air drying the compressed food using heated air.