GB2126865A - Improvements in and relating to the processing of meat - Google Patents

Abstract

The colour, flavour and water- binding capacity of fresh meats, especially poultry meat, can be improved by incorporating an acid phosphate. Particularly preferred are the acidic sodium and potassium salts of phosphoric and pyrophosphoric acid when present in an amount of 0.3-0.7% (based on weight of meat). A meat extender such as textured vegetable protein can also be present.

Description

SPECIFICATION Improvements in and relating to the processing of meat The present invention relates to a method for improving the colour and flavour of meat, whilst simultaneously improving water retention of the meat, by incorporating a phosphate.

The use of phosphates is very well known in all forms of food processing, including meat processing, and the use of polyphosphates to increase the water retention of poultry is probably well known even to the layman. A review of the use of phosphates in food appears in the chapter "Phosphates in Food Processing" in the Handbook of Food Additives, second edition, published by The Chemical Rubber Co., Ohio U.S.A. (1972), pages 617-780.

The common phosphoric acids are polybasic and can, therefore, each form a number of salts, ranging from acidic to alkaline with any given metal, although, in commercial practice, not all of the theoretically possible salts are used, for reasons of economy and commercial availability. In practice, for reasons which are well known to the food technologist, the phosphates most commonly used in meat processing are the alkaline phosphates and, although certain acid phosphates have been approved by the regulatory authorities in many countries, e.g. the U.S. Department of Agriculture, to improve water retention in various cured and/or cooked meats and are known to improve the colour of cured meats, in practice the alkaline phosphates are preferred.The acid phosphates are, however, not infrequently used in various non-meat applications, where the acidic flavour they impart is either acceptable or desirable.

Most of the phosphates in common food processing use have been classified by the U.S. Food and Drug Administration as "GRAS" (i.e. generally recognised as safe).

We have now surprisingly discovered that acid phosphates, when used in fresh meat (the term "fresh meat" being defined below) not only, as would be expected, improve water retention but also improve the colour and most especially the flavour of the meat after it has been cooked.

The present invention thus consists in a meat composition comprising fresh meat (as herein defined) having added thereto at least one acid phosphate.

The invention further consists in a process for preparing a meat composition in which fresh meat is impregnated with an acid phosphate.

The term "fresh meat" as used herein means meat which has been neither cured nor cooked, and includes meat which is or has been frozen. The world "meat" means the flesh and other edible parts of animals, including fish, poultry and mammals (excluding humans). The word "meat" is thus not limited merely to muscle meat but includes other parts of the animal which can be used in foodstuffs and may, as with offal, brains and skin, even be considered a delicacy in some regions.

The fresh meat to which the present invention may be applied is preferably the meat of mammals, for example pork, beef, veal, mutton, lamb or venison, or of poultry, for example chicken, turkey, duck or goose, as well as other edible portions of the respective animals, namely pigs, cattle, sheep, deer, chickens, turkeys, ducks and geese. The invention is, as will be explained hereafter, of especial value in the treatment of poultry meat, most especially the meat of chicken and turkeys.

The fresh meat employed in the present invention may be used in admixture with various meat extenders, as is well known in the art. Of the available meat extenders, we prefer to use vegetable protein materials, especially protein isolates, caseinates or microbial protein. Particularly preferred are protein materials derived from the oil seeds, e.g. soybeans, rapeseeds, cottonseeds, sesame seeds, groundnuts or sunflower seeds, of which protein materials derived from soybeans are preferred by virtue of their excellent nutritive value, price and availability, although the preferred material may vary from region to region, depending upon locally available produce.

Where a meat extender is employed, its amount will vary, depending many factors, including the target price of the product, the desired nutritive value of the product (for example high levels of protein isolate will provide a much higher level of available protein pel unit weight then will most meats alone), special dietary requirements (for example, a high level of protein isolate may be used to maintain protein intake whilst reducing the intake of saturated, animal fats, thus providing a far healthier product) and other factors peculiar to individual markets. The level of non-meat materials present in meat products may also be regulated by national legislation, which may vary from country to country and this, also, has to be taken into account.In general, however, we would normally prefer that the fresh meat content of the meat composition of the invention should be at least 10% by weight (based on the total weight of the composition), the balance (if any) being meat extender, water, acid phosphate and, if desired, other additives. The balance between meat extender and added water is preferably that found in the fresh meat, and so the water preferably comprises from 70 to 80% of the total weight of meat extender plus water, the meat extender correspondingly being from 30 to 20% by weight on the same basis. However higher levels of fresh meat in the composition are possible and may even be desirable for certain applications, for example levels of at least 50% or at least 60% meat and possibly even at least 80%, based on the total weight of the meat composition.The substantial flavour enhancement achieved by incorporation of an acid phosphate in accordance with the present invention is of particular value with products containing a meat extender, as meat extenders normally are (or are designed to be) essentially tasteless and thus have the effect of diluting the natural meat flavour The inclusion of an acid phosphate can enable this flavour to be improved, even without the use of artificial flavours. However, even a meat composition whose protein content is wholly fresh meat will benefit from incorporation of an acid phosphate in accordance with the present invention because of the improved flavour.

There is a large number of phosphoric acids available and the acid salts of any of these may be employed. Particularly preferred by reason of the excellent results achieved and their availability, are the salts of pyrophosphoric acid or of orthophosphoric acid, most especially the sodium or potassium salts of the phosphoric acids. In general, the sodium salts are preferred over the potassium salts, since the sodium salts are substantially cheaper and are more readily available; however, the potassium salts generally have a less astringent flavour and thus may be preferred for applications where the improved flavour outweighs the added cost, e.g. if a high level of acid phosphate in the product is desired.The preferred salts are those commonly known as sodium acid pyrophosphate (i.e. disodium pyrophosphate) and acid sodium phosphate (i.e. monosodium orthophosphate), especially the former, and their potassium counterparts.

The benefits of improved water retention, improved colour and improved flavour will be imparted to the meat composition by the acid phosphate over a wide range of concentrations. However, if the level of acid phosphate in the composition is too low, then these benefits may not be perceptible to the consumer and, accordingly, we prefer that the amount of acid phosphate in the product should be at least 0.2% by weight, more preferably at least 0.3% by weight and most preferably at least 0.5% by weight. On the other hand, if the level of acid phosphate is too high, it will begin to impart undesirable flavour and other characteristics to the product and, of course, too high a level would be wasteful.

Accordingly, the upper limit to the amount of acid phosphate to be incorporated into the composition will depend upon the particular phosphate employed (especially its flavour characteristics), the type of meat composition into which the phosphate is to be incorporated and the particular market in which the product is to be sold. This amount will normally not be greater than 3% by weight, as the flavour imparted by the phosphate itself (especially if it is a sodium salt) will normally be perceptible and may be most unpleasant at this level. Accordingly, we prefer that the amount should be not greater than 1% by weight (at which level, the flavour of the phosphate may begin to become perceptible). The most preferred level of phosphate is within the range from 0.5 to 0.7% by weight.The percentages of phosphate given herein and throughout this specification are based upon the weight of the fresh meat alone.

The fresh meat is preferably impregnated with the acid phosphate by contacting the meat with an aqueous solution or suspension of the phosphate although, for some purposes (especially where the meat is finely comminuted), this may be done simply by intimately mixing the meat with the solid acid phosphate. The concentration of the solution or suspension is preferably from 5 to 30% by weight, more preferably from 10 to 1 5% by weight and the meat may be contacted with the solution or suspension by a variety of methods well known to those skilled in the art, for example, injection, mixing, massaging or tumbling.

In addition to the acid phosphates required by the present invention, various other common food additives may be incorporated into the meat composition, especially, but not exclusively, salt (sodium chloride).

The benefits obtained by incorporating an acid phosphate in accordance with the present invention are threefold.

First, as is well known, phosphates improve the water retention of meat. Meat requires a substantial water content to give a cooked product which is juicy, flavourful and tender. However, the majority of processes to which meat is commonly subjected reduce the amount of water it contains and reduce its water-binding capacity. Upon slaughter of the animal, the water-binding capacity of meat decreases, until it has reached a minimum when rigor mortis is complete. Thereafter, aging of the meat may increase the water-binding capacity to some extent, but it is never restored to the level of living tissue.Furthermore, freezing, and subsequent thawing, of meat can very substantially reduce the water content and water-binding capacity of the meat; at its extreme, this leads to the condition known as "freezer burn", where such levels of water have been lost and the water-binding capacity of the meat has been reduced to such a low value that the meat can never recover.

Moreover, meats, especially chicken and turkey, when cooked, lose a lot of water and dissolved solids (flavour and nutrition). Even at pasteurizing temperatures (72-750C), up to 20% of the weight can be lost, whilst at sterilizing temperatures (about 11 5"C) 25-30% can be lost; frying and roasting produce weight losses between these values and the resulting meat may be dull and dry. Salt and alkali phosphates can reduce these losses, but tend to turn poultry meat pink, which the consumer regards with disfavour.

Incorporation of acid phosphates improves water retention without turning the product pink.

Second, the incorporation of an acid phosphate in accordance with the invention surprisingly improves the colour of the meat after it has been cooked. Although the reasons for this are not known, the effect on the cooked meat of incorporating an acid phosphate in the fresh or uncooked meat is to reduce the tendency of the meat to turn red on cooking and increase the lightness (which normally tends to decrease on cooking). In the case of poultry meat, the consumer is accustomed to regarding the white meat of the bird as the most desirable (although the dark meat is of at least the same nutritional value and may have better flavour) and, accordingly, in processed meat products, those having a whiter and lighter appearance are regarded as the premium product, whilst products having a darker or redder appearance appear to the consumer less desirable.In the case of red meats, the consumer associates freshness with a bright red colour; oxidation of pigments in the meat, however, quickly darkens this colour, giving an appearance which many consumers will associate less readily with fresh meat, although in fact, the quality of the meat may be at least as good as, and possibly even better than, that of meat having a "fresher" appearance. The incorporation of acid phosphates in accordance with the present invention reverses this process and restores the bright red colour associated with fresh red meat.

Third, the incorporation of acid phosphates surprisingly enhances to a substantial degree the natural meat flavour, in a way which is not fully understood. The effect is certainly not that of adding the natural flavour of the acid phosphate to the flavour of the meat, as the flavour of the acid phosphates employed in the present invention at perceptible concentrations is far from meaty and, indeed, is most unpleasant; in any case, as already noted, the preferred levels of acid phosphate are below those at which the flavour of the phosphate is perceiptible. Moreover, the effect is not observed with alkaline or neutral phosphates. Whatever the cause, the effect is to enhance the natural flavour of the meat to which the acid phosphate is applied.Accordingly, this is of particular benefit to those products which incorporate meat extenders (which would normally dilute the meat flavour), since it enables the natural meat flavour to be enhanced without the need to add any artificial or synthetic flavours. In the case of products containing approximately 100% meat, this flavour enhancement is also of value -- there is a widespread belief that meat, and especially poultry, no longer has the flavour that it did some decades ago - the incorporation of an acid phosphate in accordance with the present invention enables the flavour to be improved to a level where the products are perceived by the consumer as being equal to or even better than the products of the "good old days".

The invention is further illustrated by the following Examples.

EXAMPLE 1 White or dark turkey meat was trimmed and desinewed, after which it was minced through a kidney plate. A brine having the composition shown in the following Table 1 was then added to each 100 kg of meat and thoroughly mixed. The meat was packed into cans and cooked to a centre internal temperature of 750C.

The cooked meat was then removed from the cans, and samples were taken and observed on a Hunter Laboratories colorimeter to assess the colour. The results are reported in Table 1, in which the "A" value is a measure of redness and the "L" value is a measure of whiteness. The amounts of sodium acid pyrophosphate were varied, as shown in the Table, and the experiment was also carried out using white or dark turkey meat alone and using meat to which just water or salt and water had been added.

Runs 1-5 used white turkey meat; Runs 6-10 used dark turkey meat.

TABLE 1

Run Brine Composition (kg) "L" "A" No. Water Salt ASP value value 1 0 0 0 71.7 2.4 2 20 0 0 72.6 1.6 3 20 1.2 0 71.3 1.7 4 20 1.2 0.55 76.1 0.2 5 20 1.2 3.3 75.1 -0.3 6 0 0 0 51.7 7.2 7 20 0 0 53.5 6.9 8 20 1.2 0 51.6 6.5 9 20 1.2 0.55 54.1 3.9 10 20 1.2 3.3 53.0 3.3 In the above Table and hereinafter, the abbreviation "ASP" means sodium acid pyrophosphate.

Comparing the results obtained in Runs 4-5 and 9-10 with those obtained in Runs 1-3 and 6-8 (where no ASP was employed), respectively, it can be seen that, in all cases, there is a very substantial reduction in the "A" value, that is the degree of redness. The "L" value increased significantly. The overall subjective effect is an increase in the whiteness and lightness of the meat and, in the case of the dark meat (Runs 8-10), the appearance of the cooked product was more similar to white meat than to the cooked dark meat.

When evaluated organoleptically, the products of Runs 4--5 5 and 9-10 all showed a dramatic increase in perceived meaty flavour and meaty fibrous texture. However the products of Runs 5 and 10 also showed an astringent flavour typical of the phosphates and were for this reason, less desirable.

By way of comparison, the above experiments were repeated, except that the ASP was replaced by an alkaline phosphate (Nutriphos HP, a product of McAuley Edwards Ltd., 9 High Street, Baldock, Hertfordshire, SG7 6AZ, England, having a pH of 9.0-9.2). The results are shown in Table 2. It is clear that the presence of alkaline phosphates substantially increased the redness whilst not greatly affecting the lightness.

TABLE 2

Run Brine Composition (kg) "L" "A" No. Water Salt Alk. Phos. value value 1 0 0 0 71.7 2.4 2 20 1.2 0 71.3 1.7 3 20 1.2 0.55 74.5 2.1 4 20 1.2 3.3 70.4 6.2 5 0 0 0 51.7 7.2 6 8.9 1.2 0 51.6 6.5 7 8.35 1.1 0.55 52.4 7.6 8 7.8 1.1 1.1 50.6 9.7 EXAMPLE 2 White or dark chicken meat was trimmed and desinewed, and then minced through a kidney plate'.

20% by weight water, followed by 0.5% by weight sodium acid pyrophosphate (if used), followed by 2% by weight salt (the percentages being based upon the original weight of the meat) were then added and the whole was thoroughly mixed. The mixture was then packed into cans and cooked to a centre internal temperature of 750C. After cooking, the products were weighed to assess the yield, i.e. the cooked weight expressed as a percentage of the green weight of the meat (the green weight is the weight of the meat prior to cooking and prior to addition of water, phosphate and salt). The results are reported in Table 3. The experiment was also carried out with white or dark chicken meat to which nothing or just water had been added and these results are also reported in Table 3.

TABLE 3

Run ASP Salt Water "L" "A" Yield No. % wt % wt % wt value value 1 0 0 0 75.0 1.9 86.4 2 0 0 20 75.5 1.1 - 3 0 1 20 74.2 1.8 100.2 4 0.5 1 20 78.8 0.0 113.7 5 0 0 0 54.7 6.7 84.8 6 0 0 20 56.0 6.5 - 7 0 2 20 54.2 6.1 95.9 8 0.5 2 20 58.0 3.4 113.7 The above Table shows the same substantial decrease in "A" value of the product with ASP as was seen in Example 1, with a significant increase in "L" value. As with Example 1, the products with ASP appeared subjectively lighter and whiter and the cooked dark meat showed a greater resemblance to untreated white meat.

The results also show that, although the addition of salt and water resulted in some increase in yield, the addition of 0.5% by weight ASP very substantially increased the yield, by nearly 20% of the green weight.

When evaluated organoleptically, the products of Runs 4 and 8 both showed a dramatic increase in perceived meaty flavour and meaty fibrous texture, compared with the products of Runs 1-3 and 5-7.

EXAMPLE 3 White turkey meat was trimmed and desinewed, after wich it was minced through a kidney plate.

The meat was then treated as follows: Run 1 100 kg of meat was used alone.

Run 2 100 kg of meat was thoroughly mixed with 10 kg of a brine containing 1.1 kg of salt, 0.55 kg of alkaline phosphate and 8.35 kg of water.

Run 3 100 kg of meat was mixed with 10 kg of the same brine as was used in Run 2 and with 18 kg of a dispersion of 3 kg of isolated soy protein in 1 5 kg of water.

Run 4 100 kg of meat was mixed with 10 kg of a brine containing 1.1 kg of salt, 0.55 kg of ASP and 8.35 kg of water.

Run 5 100 kg of meat was mixed with 10 kg of the same brine as was used in Run 4 and with 18 kg of the same isolated soy protein dispersion as was used Run 3.

Each of the products was then packed into cans and cooked to a centre internal temperature of 750C. The cans were then weighed, to determine the weight of the product contained therein. The results are reported in Table 4.

TABLE 4

Weight (kg) of Run No. cooked product 1 83.7 2 100.2 3 120.0 4 94.0 5 114.0 It is clear that the acid phosphate, ASP, was less successful than the alkaline phosphate in reducing weight loss, although, in all of the runs using a phosphate (Runs 2-5), the cooked weight of the product was greater than that of the turkey meat alone (Run 1) and the products were moister and juicier.However, the turkey flavour in Runs 2 and 3 was perceptibly reduced when compared with that of Run 1, and the reason for this is clear -- 100.2 kg or 120.0 kg of cooked product having the flavour derived from 100 kg of fresh meat (corresponding to 83.7 kg of cooked meat) clearly must have a reduced concentration of flavour components. Surprisingly, however, the products of Runs 4 and 5 actually had an enhanced turkey flavour when compared with the product of Run 1. Even when Run 5 was repeated, but the quantity of isolated soy protein dispersion added was increased sufficiently to give a final cooked weight of 120.0 kg (the same as Run 3, using alkaline phosphate), the turkey flavour was still much enhanced.

The experiments were repeated with dark turkey meat, and with white and dark chicken meat and also with all four types of meat without salt and without isolated soy protein dispersion and, in all cases, the poultry flavour was enhanced.

In all of the above Examples, the meat used for each series of experiments was derived from a number of birds and thoroughly mixed, so as to give a consistent product on which to demonstrate the above results. Clearly, the colour and flavour-of poultry varies {in some cases, quite considerably) from bird to bird. Accordingly, the values given above are not absolute values but show trends.

Claims (23)

1. A meat composition comprising fresh meat (as hereinbefore defined) having added thereto an acid phosphate.

2. A composition according to claim 1, in which said meat is from a non-human mammal.

3. A composition according to claim 1, in which said meat is poultry meat.

4. A composition according to claim 3, in which said meat is chicken or turkey.

5. A composition according to any one of the preceding claims, additionally comprising a meat extended.

6. A composition according to claim 5, in which said meat extender is a vegetable protein material.

7. A composition according to claim 6, in which said vegetable protein material is a protein isolate.

8. A composition according to claim 6 or claim 7, in which said vegetable protein material is derived from soybeans.

9. A composition according to any one of claims 5 to 8, in which the meat content of said composition is at least 10% by weight.

10. A composition according to claim 9, in which said meat content is at least 50% by weight.

11. A composition according to any one of claims 1 to 4, in which the protein content of said composition is 100% meat.

12. A composition according to any one of the preceding claims, in which said acid phosphate is an acid salt of pyrophosphoric acid or orthophosphoric acid.

13. A composition according to claim 12, in which the salt is the sodium or potassium salt.

14. A composition according to claim 12, in which said salt is sodium acid pyrophosphate.

1 5. A composition according to any one of the preceding claims, in which the amount of said acid phosphate is at least 0.3% by weight, based on the weight of the meat.

16. A composition according to claim 1 5, in which the amount of said acid phosphate is at least 0.5% by weight, based on the weight of said meat.

17. A composition according to any one of the preceding claims, in which the amount of said acid phosphate does not exceed 3% by weight, based on the weight of said meat.

18. A composition according to claim 17, in which the amount of said acid phosphate does not exceed 1% by weight, based on the weight of said meat.

1 9. A composition according to any one of claims 1 to 14, in which the amount of said acid phosphate is from 0.3 to 0.7% by weight, based on the weight of said meat.

20. A composition according to claim 1, substantially as hereinbefore described with reference to any one of the foregoing Examples.

21. A process for preparing a meat composition according to any one of the preceding claims, which comprises impregnating said fresh meat with said acid phosphate.

22. A process according to claim 21, in which said impregnation is effected by injection, mixing, massaging or tumbling.

23. A process according to claim 21, substantially as hereinbefore described with reference to any one of the foregoing Examples.