Claims
- 1. A method for producing freeze dried cooked meats which are more easily and completely rehydratable, comprising the steps of:
- a. trimming a quantity of raw solid meat of heavy connective tissue and excess fat;
- b. grinding or emulsifying a first portion of said trimmed meat and flaking or chunking a second portion of said trimmed meat into flakes or chunks which are 2.5-6.0 cubic inches in volume;
- c. mixing said ground or emulsified first portion and said flaked or chunked second portion with about 2.0% to about 6.0% of the formula weight water, about 0.5% to about 2.0% of the formula weight salt, about 0.1% to about 0.5% of the formula weight phosphates and about 0.5% to about 5.0% of the formula weight an adjunctive hydrophilic ingredient until sufficient myofibrillar proteins are extracted to render the mixture moderately tacky and continuing said mixing until the water, salt, phosphates and adjunctive hydrophilic ingredients equilibrate throughout said mixture;
- d. preparing a meat log by tightly stuffing said mixture into a moisture and gas impermeable container, wherein said container is a casing comprising a fibrous cellulose exterior laminated onto a saran film interior, said casing fitting tightly to the surface of said meat so as to keep moisture in equilibrium within said meat product during cooking;
- e. cooking said meat log at a predetermined temperature for sufficient time to achieve a predetermined product center temperature;
- f. freezing said meat log;
- g. slicing or dicing said meat log into portions suitable for freeze dehydration;
- h. freeze vacuum dehydrating said portions to a predetermined moisture level; and
- i. packaging said dehydrated meat in an airtight container in the absence of oxygen.
- 2. The method as described in claim 1 wherein said salt is selected from the group consisting of sodium chloride and potassium chloride; said phosphate is selected from the group consisting of the salts of sodium pyrophosphate, orthophosphate, hexametaphosphate and tripolyphosphate and the adjunctive hydrophilic ingredients are selected from the group consisting of sodium carboxymethyl cellulose, microcrystalline cellulose, gum arabic, polyvinylpyrrolidone, arabino gallactan, xantham gum, kayara gum, guar gum, gum tragacanth, locust bean gum, malto dextrins and hydrocolloids.
- 3. A meat product prepared in accordance with the process of claim 1 wherein said meat product has an expanded matrix as a result of the mixing of the meat with water, salt, phosphates and adjunctive hydrophilic ingredients and said meat product rehydrates completely within 8 minutes upon being placed in 180.degree. F. water.
BACKGROUND OF THE INVENTION
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.
This invention relates to a method of producing freeze-dried cooked meats which rehydrate rapidly and avoid problems caused by meats which do not rehydrate fully, and, typically have numerous unpalatable hard spots. This improvement is accomplished by expanding the matrix of the meat so as to provide pathways for water to rehydrate the meat.
It is well known that foods may be preserved for long periods by dehydration and that dehydrated meat items frequently do not rehydrate quickly or to the extent required for optimum palatability and tenderness. Among dehydration methods, freeze drying is the least detrimental to meat texture and rehydratability. Freeze drying, the sublimation of ice to water vapor under vacuum, results in drying without significant change in product volume. The meat matrices obtained are therefore significantly more porous that those of meats dried by other means. While the rate and extent of rehydration of freeze dried meats is superior to that of meat items otherwise dried, rehydration remains relatively slow and incomplete, resulting in "hard spots" in cooked rehydrated meats.
In order to produce dehydrated meats requiring only rehydration prior to their being consumed, they must be cooked prior to their being dried. Dehydrated cooked meats may be the meat component of stews; or steaks, chops or pattie-like products. Typically, cooked meats destined to be freeze dried are heated to an internal temperature of 140.degree. F. or more by dry or moist heat resulting in pre-dehydration moisture and fat cook-out in the range of 25%-50% of the meat's raw weight.
Cooking also results in disruption of cell membrane function and in coagulation of intercellular and intracellular proteins. The heat denaturation of meat proteins creates a largely static condition with respect to water and substances in solution within and external to cells which comprise meat tissue. In living tissue, the mass of individual cells imbibe or excrete water in response to changes in osmotic pressures as a result of changes in solute level, thereby maintaining optimum solute/solvent concentration for cell function. Fresh, raw meats retain much of this function which cooking largely destroys. Changes in meat density and its physiological state as a result of heat denaturation contribute directly to problems relative to the rehydration of meats which have been cooked and subsequently freezed dried.
Rehydration of freeze dried cooked meat generally involves its immersion in 150.degree. F. or warmer water. Since cooked meat protein is largely denatured and cell membranes no longer function effectively with respect to osmotic gradient changes, hydration occurs primarily by absorption. Water moves gradually from surface to center of the meat particles, the rate of absorption being dependent on a number of factors including the dried meat's affinity for water, its density, its volume, the amount of fat, the degree of myofibrillar protein cross linking, the concentration of salts and their availability, the temperature to which the meat was cooked initially and the temperature of the rehydration water. These factors are directly affected by cooking. Meat protein which has been denatured due to cooking loses much of its affinity for water. Conventional cooking methods increase meat density by evaporative and syneresis effects and cause rendered fats to coagulate in interstitial spaces within the meat structure, thus further inhibiting penetration by water in meat which has been dried. Increased meat density may heighten the potential for myosin cross linking, which also inhibits rehydration. Obtaining hot water and maintaining its temperature for sufficient time to rehydrate the meat is not always practicable for the military. As a result, the cooked meat components of freeze dried foods of the prior art are slow to rehydrate, do not fully rehydrate and often contain numerous unpalatable "hard spots".
US Referenced Citations (15)
Foreign Referenced Citations (1)
| Number |
Date |
Country |
| 20679 |
Apr 1972 |
ATX |
Patent Grant
H35
