IL36339A - A stable food material,method of producing it and a method of preserving such materials - Google Patents

Description

A STABLE POOD MATERIAL METHOD OF PRODUCING IT AND A METHOD OF PRESERVING SUCH MATERIALS na»Eft ntw ms***? ΠΡ»Ε »3»g» naitn lan 1 TD Τ31Π ¾7 due to their lov moisture content, about 10 by weigi jj?jr less, they are very stable and resist mold growth and baoteria spoilage* Intermediate moisture products have a moisture content of about 25 to 40 jgy weight* Due to the higher moisture content of the intermediate moisture products, they " . . . s, ■ * must be stabilized with preservatives to provide suf icient baeteristatic and antirayeotie activity in the material to give it an acceptable shel nlife. Sugar, salt, sodium and - potassium sorbate, sorbic acid and many other preservative materials have been used successfully to preserve intermediate ffloisture materials* Due to the high stability of dry and intermediate moisture products, they can be packaged in relatively inexpensive paper or polymer film containers and kept in an ambien environment fo long periods of time without spoiling* The materials do not need to be sterilized prior to paeK ^ing, nor do they require refrigeration after packaging* High moisture products have a moisture content of from about 50 to 80$ or more by weight* The high moisture level of the material has required that the material be sterilised after oanning in order to prevent spoilage from bacterial, and mold growth if a shelf life of more, than a ew FOOD PRESERVATION ! ! Abstract j i A method of preserving high moisture food products is disclosed which enables food materials such as fresh flesh to be preserved in a stable, nutritious and wholesome form without refrigeration or resorting to canning and autoclaving techniques. ; The preserved materials may be packaged in transparent, flexible Ij containers and stored under ambient conditions for periods of a i year or more. The materials may be preserved in the uncooked state or they may be cooked and preserved. The method involves impregnating the materials with a preservative such as 1,2-pro- immers ing panediol. Impregnation can be accomplished by emexsisg the materials in a bath of the preservative material or by mixing.

Background of the Invention ; Preservation of food materials is a problem which continually confronts the food industry, particularly where canning methods are not possible or desirable. It is a continuing problem in the industry to preserve food materials, such as flesh or fish, in a marketable state while it is transported from the site of production to the market. Fresh animal flesh, meat and fish, has a high moisture content and is difficult to preserve. After reaching the market, the food material must be preserved for sale to the consumer. Fresh vegetables, fruits and berries also have a high moisture content and, as a consequence, have a very limited shelf life when sold in the fresh state. > Food materials are commonly marketed in three forms: certain colloids, as a preservative coating for foodstuff* containing minimal amounts of moisture* U.S. patents 3,493,382 and 3,493,383 disclose that propylene glycol is an equivalent to glycerine in preserving anhydrous liquid systems Also, U.S. patent 2,970,919 teaches that propylene glycol, a aIon*? with other preservatives such as sodium benezoat and isoascorbic acid, is an equivalent to glycerine in the preservation of foodstuffs containing about 31 ' moisture.

None of the combinations of said preservatives vas shovn to be adapted to stabilize high moisture products, so that sterilization remained the only method for preserving the products.

Summary of the Invention Ve have discovered that only propylene glycol, unlike other preservatives, will protect against both mold and yeast attack in high moisture foodstuffs, without the aid of other preservatives or colloids and gums which absorb part of the moisture and without increasing the amount of propylene glycol utilized in foodstuffs containing greater amounts of moisture.

Our method for preserving high moisture food material enables us to package the materials in inexpensive packaging and to store the materials under room temperature conditions for long periods of time. The materials are stable and will not support bacterial or mycotic growth. The materials can b» packaged by simple, inexpensive processes and do not require expensive canning and sterilizing techniques to preserve them. The materials can be packaged in the uncooked state or they may be cooked. Many products can be preserved by the process of this invention, including high moisture pet foods. High moisture materials which are suitable for human consumption may be preserved equally as well. Proteinaceous materials such as meats, stews and pates have been successfully preserved. Other materials which have been successfully preserved are potato salad, fruits, melons, tomatoes, cherries, tomato paste and other vegetable materials. The process of the invention has the unique advantage of allowing many fresh meat and vegetable materials to be preserved in a marketable state without canning for times much beyond their normal shelf life and without the use of palatability reducing and nutritionally harmful or degrading preservatives. It is known that many preservative materials such as sorbic acid and sorbate salts have a palatability reducing effect and some materials such as some sugars may have undesirable physiological effects on animals.

Simply stated, the process of preserving foods having moisture contents of from about 50 to 80% or more by weight involves impregnating the moist materials with a preservative such as 1,2-propanediol (propylene glycol). This preservative system is substantially complete when used as disclosed and substantially eliminates the need for preservatives of a palatability reducing or physiologically undesirable character. The preservative is added to the materials in proportions of from at least about 10% by weight. A range of about 15% to 30% by weight is preferred. The preservative can be added to the materials in a variety of of preservative applied to the materials can be removed, for example, by rolling the treated particles to squeeze out the excess preservative. The final treated product will normally have a preservative content of at least about 10% to 30% by weight, a moisture (HgO) content of about 50% to 80%, or more by weight and a solids content of about 8% to 35% by weight.

The solids content of the product will consist of nutritional and therapeutic components necessary to provide a satisfactory ration, i.e., one having the complete nutritional and healthful properties desired. For example, the solids will be the vitamin, mineral, protein, energy, and therapeutic materials needed for adequate health and nutrition of the animal for which the food product is designed.

' The final product may contain additional stabilizing, coloring and flavoring ingredients in addition to the preservative materials used in order to promote specific coloring or flavoring effects, but such materials will not normally be of the palatability reducing or degrading type or, if necessary, their use will be minimal. The standard FD&C food colors, BHA, BHT, smoke flavor, hamburger flavor, minerals and vitamins are materials which may easily be added to the products of our invention. It is expected that the product may contain additional nutritional and therapeutic materials to improve or increase the nutritional value of the final product, to render the product nutritionally complete or therapeutically more desirable.

This is readily accomplished due to the lack of palatability reducing and physiologically undesirable preservative materials in the final product. The product does not contain product. By using the preservative system of the invention it is also possible to eliminate sugars as a preservative material and to eliminate the physiological disorders associated with high sugar levels.

After the materials are treated by the process of this invention they are packaged and prepared for shipment to the consumer. Packaging may be accomplished by simply wrapping the materials in a paper or polymer film wrap or tube. Polypropylene, foil wrap and polyvinyl chloride (PVC) film wrapping materials have proven to be satisfactory for maintaining the preserved products in a stable palatable form.

Description of the Preferred Embodiments The following examples are included to illustrate the invention to those skilled in the art and are not intended to limit the scope of the invention: Example 1 Beef liver having a moisture content of 72.5% by weight was ground on a Hobart grinder having 3/32 inch plate openings. The ground liver was divided into seven 50 gm. portions. A negative control containing no additional material was prepared by sealing a 50 gm. portion in a plastic bag. Samples containing 5, 10, 15, 20, 25 and 30% by weight 1,2-propanediol were prepared from the remaining portions by mixing in a Waring blender, and the 1,2-propanediol samples were sealed in plastic bags. The 1,2-propanediol samples and the negative control were incubated for seven days. Bacterial cultures were taken from the samples and the control. The results of the culture tests are shown in Table I. ίΡ-236 TABLE I BEEF LIVER BACTERIAL TEST Example 2 An experiment similar to Example 1 was conducted by reconstituting dried powdered eggs at a moisture content of 607o by weight. A negative control was prepared and samples containing 5, 10, 15, and 20% 1,2-propanediol were prepared. The samples and control were sealed in plastic bags and cooked at 180° F. for ten minutes to coagulate the egg protein. The samples and control were incubated and cultured as described in Example 1. The results^ of the tests are shown in Table II.

TABLE II COOKED EGG BACTERIAL COUNT Initial 7th day Bacterial Count Bacterial Count Preservative (# gram) (# gram) SP-236 Example 3 The experiment of Example 2 was repeated, except the egg was not cooked. The results of the tests are shown in Table III.

TABLE III RAW EGG BACTERIAL COUNT Exam le 4 The experiment of Example 1 was repeated using fresh carcass beef having a moisture content of 69.15% by weight.

Samples containing 5, 10, 15, 20, 25 and 30%, 1,2-propanediol were tested; the bacterial count was taken at three days and seven days. The results of the tests are shown in Table IV.

TABLE IV CARCASS BEEF BACTERIAL COUNT Initial 3rd day 7th day Bacterial Count Bacterial Count Bacterial Count Preservative (# gram) (# gram) (# gram) % 4,600 3,000,000 3,000,000 SP-236 Example 5 A high moisture pet food was prepared by cubing 84. 5%. of carcass beef having a moisture content of 69 . 15%, by weight. 157o of 1 , 2-propanediol containing .05% of garlic powder and 1/2% mineral salt were mixed with the cubed beef in a rotary mixer for 30 minutes. The cubed beef was sealed in plastic bags and stored at room temperature. After seven d ys' storage the material appeared fresh. There was no noticeable odor or appearance of spoilage. A sample incubated for seven days appeared to be fresh and free from odor or spoilage. The material had a total bacteria count of less than ten per gram after seven days incubation.

Samples of the material were fed to dogs. The animals consumed the material readily with no observed adverse effects.

Example 6 Example 1 was repeated using fresh shrimp having a moisture content of about 607« by weight. A negative control and samples containing 5 , 10 , 15 and 20% by weight 1 , 2-propanediol were prepared. The bacterial count was taken after one day and after four days. The results of the tests are shown in Table V.

TABLE V SHRIMP BACTERIAL COUNT Initial 1st day 4th day Bacterial Count Bacterial Count Bacterial Count Preservative (# gram) (# gram) (# gram) Control (0%) 420 ,000 3,000,000 3,000,000 % 290,000 3,000,000 3,000,000 % 01,000 470,000 3,000,000 SP-236 Example 7 Example 1 was repeated using fresh channel catfish having a moisture content of about 65% by weight. A negative control and samples containing 5, 10, 15, 20 and 25%, by weight 1, 2-propanediol were prepared. The bacterial count was taken after one day and after four days. The results of the tests are shown in Table VI.

TABLE VI FISH BACTERIAL COUNT Example 3 Example 1 was repeated using fresh honeydew melon having a moisture content of about 90% by weight. A negative control and samples containing 5, 10, 15 and 20% by weight of 1,2-propanediol were prepared. The bacterial count was taken after one day and after four days. The results of the tests are shown in Table VII.

SP-286 TABLE VII MELON BACTERIAL COUNT Initial 1st day 4th day Bacterial Count Bacterial Count Bacterial Count Preservative (# gram) (# gram) (# gram) Control (0%) 39,000 3,000,000 3,000,000 % 31,000 39,000 3,000,000 % 300 10 440 % 760 520 490 % 490 430 310 Example 9 A ripe honeydew melon was preserved by injecting 1,2-propanediol into the melon. The melon contained 15%, by weight of the preservative. The preserved melon was stored at room temperature. After seven days the melon was checked for signs of spoilage. The flesh appeared firm and clean. There were no noticeable off odors or flavors in the flesh and it appeared fresh.

Example 10 A nutritionally complete and therapeutically beneficial diet for dogs was formulated as follows : Ingredient Parts o Moisture Con ent Carcass beef 11.9 60 Whole chicken 11.9 63 Beef Melts 11.9 76 Beef lungs 9.0 64 Expanded soy fibers 0 _ SP-286 Ingredient Parts 7„ Moisture Content 1,2-propanediol 15.0 0 Water for processing 31.3 100 The meat was ground on a Hobart grinder having 1/3 inch plate openings and mixed with the water and the other solid ingredients. The wet mixture was impregnated with the 1,2-pro-panediol and was cooked in a Sandvick infrared fryer. After 2 minutes' cooking the product had absorbed the cooking liquids and the product was removed from the fryer. The product had a final moisture content of 52.47o by weight (Karl Fischer). The product was stable and exhibited a long shelf life. It was fed to dogs after storage for three months at room temperature and provided a highly palatable and nutritionally complete ration. Example 11 A beef shish kebab product was prepared for human consumption as follows: A 903 gram portion of round steak was cubed in one inch cubes and immersed in 136.2 grams of 1, 2-propanediol for about 30 minutes. A marinade sauce was prepared by mixing: 3 grams garlic 206 grams corn oil 116 grams white vinegar 7 grams Worchester sauce 3 rams dry mustard 6 grams salt 1 gram pepper 1 gram Cayenne pepper .5 grams Tabasco sauce SP-286 propanediol and allowed to absorb the liquid. A marinade of: 426 grams com oil 232 grams white vinegar 37 grams Worcestershire sauce 6 grams mustard seed 6 grams cloves 12 grams salt 1 gram black pepper 1 gram Cayenne pepper was mixed and added to the vegetables and 1,2-propanediol. The meat and vegetables were marinated until saturated and removed from the marinade. The preserved meat and vegetables were packaged in unsealed foil bags and stored at room temperature. After 14 days the product was fresh and wholesome with no evidence of decay or deterioration.

Example 12 A fish en papillote product was prepared for human consumption as follows: Two pounds of fresh cut halibut was acquired and a sample sent in for bactii analysis. A 355 gram portion was placed in a skillet with 71 grams of 1,2-propanediol and heated for five minutes on each side. The heated fish was removed from heat and allowed to readsorb the liquids. A 120 gram portion of cooked shrimp was mixed with 24 grams of 1,2-propanediol and allowed to adsorb the liquid. While the fish and shrimp were marinating a mushroom sauce was prepared by mixing: 11 grams vegetable oil 13 grams wheat flour SP-286 130 grams milk 100 grams fish 68 grams washed, dried, sliced mushrooms The mixed sauce was heated until thick and 106 grams of 1,2-propanediol and 11 grams of wheat flour were added to the sauce and the sauce was again heated until thick. The liquid which had not been adsorbed by the fish and shrimp was added to the sauce and the fish, shrimp and sauce were combined, placed in oiled paper bags and stored at room temperature. After storage for 14 days at room temperature the prepared fish product had a bacterial count of less than 1,000 per gram. The initial count of the fresh fish had been 2,840,000 per gram. The prepared product had a moisture content of 53.2% by weight (Karl Fischer) and a 1,2-propanediol content of 20.37o by weight. The packaged fish product was prepared for consumption by placing the oiled paper bags containing the fish in a 400° F. oven for 30 minutes. The heated product was placed on plates in the paper bags and served. The consumers unwrapped the product by slitting the bags and ate the product. The product tasted fresh and wholesome when eaten and did not have a rancid or stale "fishy" taste even after 14 days' storage at room temperature.

It is realized that variations in these and related factors could be readily made within the concept taught herein. Hence, the invention is intended to be limited only by the scope of the appended claims and the reasonably equivalent methods, apparatuses, and products to those defined therein.

Claims (18)

SP-236 We claim:

1. A stable, nutritious food material suitable for human consumption having a long shelf life and resistance to bacterial and mycotic spoilage on storage under ambient conditions and in packaging materials which are permeable to bacterial and mycotic penetration comprising between about 50 and 80% by weight moisture, about 15 to 30%, by weight of a 1,2-propanediol preservative ¾55βί5θΘ¾ and about 8 to 35% by weight of nutritious food solids, the nutritious food solids being permeated with the 1,2-propanediol preservative aya&am to form a stable, nutritious high moisture food product.

2. A method of preserving food materials having a high moisture content comprising impregnating the food materials with a preservative consisting of 1,2-propanediol.

3. A method of preserving food materials having a high natural moisture content of at least about 50% by weight comprising impregnating the food materials with a preservative consisting of 1,2-propanediol.

4. The method of Claim 3 wherein the food material is impregnated with at least about 10% by weight of 1,2-propanediol.

5. The method of Claim 3 wherein the moisture content of the food material is between about 50 and 80% by weight, the food material is impregnated with about 15 to 307„ by weight of a 1,2-propanediol preservative, and the solids content of the preserved material is about S to 35% by weight.

6. The method of Claim 5 wherein nutritionally balancing and therapeutically active materials are added to the food materia]

7. The method of Claim 3 wherein the preservative is

8. 3Ρ-2Ϊ

9. Λ method of producing a nutritionally and therapeutically beneficial animal food material having a long shelf life and resistance to bacterial and mold spoilage on storage under ambient conditions and in conventional packaging materials which are permeable to bacterial and mycotic penetration comprisin impregnating a nutritious, proteinaceous food source with at least about 10% by weight 1 , 2-propanediol preservative, balancing the nutritional properties of the food source by adding essential vitamin and mineral sources, and forming the material into a product having moisture content of between about 50 and ϋ0% moisture by weight and about ϋ to 35% by weight nutritious food solids.

10. The method of Claim 9 wherein additional therapeutic agents are added to the food material.

11. A stable, nutritious food material having a long shelf life and resistance to bacterial and mold spoilage on storage under ambient conditions and in packaging materials which are permeable to bacterial and mycotic penetration comprising at least 10 between about 50 and 80% moisture by weight, x¾«sia3_ &$ x«» &«& by weight of a 1, 2-propanediol preservative, and about ΰ to 35% by weight of nutritious food solids.

12. The product of Claim 11 wherein the food material 15/" to 30 contains xtxAjejoE: about ¾G¾ by weight of 1, 2-propanediol preservative.

13. The product of Claim 11 wherein the food material contains a proteinaceous material as at least part of the nutritious food solids.

14. The product of Claim 13 wherein the proteinaceous

15. SP-2S6

16. The product of Claim 13 wherein the proteinaceous source is egg.

17. The product of Claim 13 wherein the proteinaceous source is fish.

18. A method of producing a nutritionally balanced human food material having a long shelf life and resistance to bacterial and mold spoilage on storage under ambient conditions and in conventional packaging materials which are permeable to bacterial and mycotic penetration comprising impregnating a high moisture nutritious food source with about 15 to 30% by weight of a 1,2-propanediol preservative, balancing the nutritional properties of the food source by adding essential vitamin and mineral sources, and forming the material into a product having a moisture content of between about 50 and 00% by weight and about by weight nutritious food solids. - 16 -