WO2000062632A1

WO2000062632A1 - A pre-cooked meat product and a process for making the same

Info

Publication number: WO2000062632A1
Application number: PCT/GB2000/001570
Authority: WO
Inventors: Bernard Trevor Matthews; David John Joll; Werner Koppers; Friedrich Buse
Original assignee: Bernard Matthews Plc
Priority date: 1999-04-20
Filing date: 2000-04-20
Publication date: 2000-10-26
Also published as: AU4307600A; GB9909039D0

Abstract

A process for making pre-cooked meat products comprising providing a body of fresh meat, injecting said body with brine, tumbling said body and thereafter cooking said body to a core temperature in the range 65-75 °C to pasteurize the meat. Said brine may comprise 1 to 5 % weight salt, and may be injected into said meat in the amount of 10-40 % by weight of the meat product. Said brine may comprise a fermented milk product such as mild yoghurt having a pH in the range 4.8 - 5.1. In some embodiments, the meat body is cut into individual portions, coated with a dry marinade comprising thickening agents and vacuum-packed prior to cooking. On cooking, water released from the meat is absorbed by the marinade to form a wet marinade and the meat is pasteurized.

Description

A PRE-COOKED MEAT PRODUCT AND A PROCESS FOR MAKING

THE SAME

The present invention relates to a pre-cooked meat product and a process for making such a pre-cooked meat product from fresh meat. The invention has particular reference to spiced and/or marinaded, pre-cooked steaks for barbecuing and/or frying. Many consumers prefer fresh meat products to frozen meat. In particular, there is a substantial market for fresh, spiced or marinaded meat products such, for example, as steaks, which are suitable for barbecuing, grilling, roasting or frying. However, even where such products are prepared and packaged under sterile conditions, they have a limited shelf-life as a result of naturally occurring meatflora within the meat. Fresh poultry and pork meat products, in particular, also present a significant food safety problem, because the meatflora of such kinds of meat often include salmonella and listeria.

Microorganisms within meat can be killed by cooking the meat, and thus the shelf-life and food safety of meat products can be improved by cooking. However, it is often desirable to re-heat such products, and this causes them to dry out which is deleterious to their organoleptic properties; such as juiciness and tenderness. It is an object of the present invention to provide a new and/or improved meat product.

Another object of the present invention is to provide a method of treating fresh meat for the purpose of providing meat products with improved shelf-life and food safety properties.

A further object of the present invention is to provide a pre-cooked product which can be re-heated without significantly impairing the organoleptic qualities of the product as compared with fresh meat cooked for the first time.

Accordingly, the present invention provides a process for making a pre-cooked meat product, which process comprises providing a body of fresh meat, injecting said body with brine, tumbling said body, and thereafter cooking said body to a core temperature in the range 65 to 75°C, to pasteurize the meat.

The invention also provides a pre-cooked meat product that is prepared in accordance with the process of the invention. Said brine may be injected into the body of fresh meat using a multi-needle injector. Typically, the amount of brine added is sufficient to compensate for the amount of water lost on cooking, so that after cooking, the meat product has about the same water content as fresh meat. Thus, when the meat product is subsequently re-heated prior to consumption, it is about as tender and juicy as if it were fresh meat cooked for the first time. In particular, the amount of brine injected into the meat product may be about 10 to 40% by weight of the meat product, typically about 10-25% by weight. After brine-injection, the water-to-meat protein ratio of the meat product may be greater than 4, whilst after cooking, the water-to-meat protein ratio may be less than or equal to 4.

Many different types of multi-needle injectors are commercially available to those skilled in the art to perform the present invention. For instance, said injector may comprise relatively thick needles for injecting viscous brine solutions into the meat, or an injector equipped with tenderising blades may be used. Preferably however an injector with slender needles is used to minimize any damage to the structure of the meat. Said brine may be injected into the fresh meat body at a pressure in the range 1 to 3 bar, depending on the kind of meat and size of needles employed. For poultry meat, such as turkey breast meat, a pressure of about 1.0 - 1.5 bar, e.g. 1.3 bar may be used, whilst for various pork cuts about 1.5 - 2.0, e.g. 1.6 bar, may be employed, using relatively narrow needles.

As brine may be used any liquid comprising free water to replace the water that is cooked-out of the meat during cooking. In some embodiments, water alone may be used. Preferably however the brine comprises salt and water; said brine may contain about 1 to 5% by weight salt, for example 2%wt, 3%wt or 4%wt.

In other embodiments, said brine may comprise a liquid fermented milk product such, for example, as yogurt, buttermilk, soured cream milk, soured milk or fermented whey having a mild pH which is selected such that, when mixed with the meat, the pH of the product does not fall too close to the isoelectric point of the meat. To this end, the overall pH of the product should be not less than 5.0, and is preferably at least 5.5. The pH of the fermented milk product that should be used to ensure that the pH of the product falls within these ranges will obviously vary depending on how much fermented milk product is incorporated into the product. However, the fermented milk product will typically have a pH of 4.8 or more, typically 4.8 - 5.1. By maintaining the pH of the product as a whole above the isoelectric point of the meat, the loss of moisture and water from the product during cooking is minimised

Preferably, the fermented milk product comprises yogurt. Said product may be injected with a mild yogurt that is prepared in the traditional manner, but is used in the process of the invention before fermentation is fully completed. Thus, after inoculation of a milk mixture with a suitable starter culture (s), the pH may be monitored until it reaches a desired value. The mild yogurt produced as a result is then made ready for use in the method of the present invention.

Prior to injection, the yogurt may be treated to destroy the yogurt cultures and any other bacteria present in the yogurt. In some embodiments, fermentation of the yogurt may be quenched by cooling the yogurt to a temperature in the range -2 to 6°C, preferably about -1°C. The yogurt may be cooled rapidly with liquid nitrogen or using a plate-heat exchanger. Alternatively, the yogurt may be heated to a temperature in the range 65 to 70°C, for instance by using a heat exchanger instead of cooled.

In order to assist in controlling accurately the pH of the yogurt to be injected into the meat piece, slow-working yogurt starter cultures are preferably used. Such slow-working yogurt cultures may comprise L.acidophilus, Bifidobacteria, and S . thermophilus . Further, the yogurt is preferably stirred continuously before use to allow accurate pH control.

In accordance with the invention, mild buttermilk may be made from the residual milk that remains after conventional butter-churning, that is separation of the milk-fat (butter) from the remaining milk substances. Said residual milk may be soured using suitable starter cultures such, for example, as Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, Leuconostoc mesenteroides subsp. cremoris and/or Lactococcus lactis subsp. diacetylactis until a desired pH is reached. Alternatively said buttermilk may be made by first souring whole milk to the desired pH with suitable starter cultures, and then quenching fermentation and churning to separate the buttermilk from the milk-fat (butter) .

Said soured creamed milk in accordance with the invention may be made by souring whole milk with a high fat content using suitable starter cultures, for example Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis and/or Leuconostoc mesenteroides subsp. cremoris to a desired pH of 4.8 or more.

Soured milk, including curd milk, may be made by fermenting whole milk having a normal fat content. Whey is a by-product of cheese manufacture in which whole milk is fermented using suitable cheese starter cultures, such as Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis and/or Leuconostoc mesenteroides subsp. cremoris in the presence of a curdling enzyme such, for example, as rennet. Once the desired pH is reached, the fermentation may be quenched and the cheese allowed to set. Once the mass has set, the cheese may be crushed mechanically, and the liquid whey extracted from the remaining solid cheese component.

In some embodiments, the fermented milk product of the present invention may comprise two or more different components, in which case it is only necessary that the overall pH of the fermented milk product is within the desired range.

In some embodiments, the fermented milk product may comprise an edible, alkaline additive to neutralise the acidity of the fermented milk product. Said alkaline additive may comprise, for example carbonated soda and/or ammonium carbonate. Phosphates and/or citrates could also be used to stabilise the mixture.

Said brine for injection may further comprise other flavourings, particularly spices. Said other flavourings and spices may constitute up to about 10% by weight of the brine. After injection, the body of meat is tumbled to distribute the brine evenly throughout the meat. Preferably, the meat is tumbled gently for 15 to 45 minutes, typically about 30 minutes. Care should be taken to avoid overtumbling of the meat product. The objective of cooking is to pasteurise the meat, and so the actual temperature and duration of cooking depends on the kind of meat being used. Preferably, the meat is cooked to a final core temperature in the range 66 to 72°C, dependent on muscle type. Obviously, if the product is not cooked sufficiently, there is a risk that not all the meat flora will be killed. On the other hand, if the meat is cooked to too high a temperature, then the meat will dry out too much on subsequent re-heating. In some embodiments, the core temperature of the meat body may be increased step-wise by increasing the cooking temperature in a series of stages. Each cooking stage may be calculated to elevate the core temperature of the meat by about 5-15°C, preferably 8-12°C. Thus a body of fresh meat may first be cooked in accordance with the invention to provide a core temperature of about 38-42°C. Once that core temperature has been stably achieved, the core temperature may be raised to about 58-62°C. Finally, the core temperature may be increased to about 71-72°C. In some embodiments, the body of meat may comprise a single portion sized steak which may be cooked individually in a full-steam environment or with dry heat. Alternatively, said body of meat may comprise sufficient meat to make two or more steaks. Said meat body may be wrapped, packaged or placed in a mould prior to cooking, and then removed from said wrapping, packaging or mould after cooking and out into individual steak portions.

After cooking, the meat product may be allowed to cool before packaging for retail. Such cooling and packaging should take place in a "high risk" sterile environment. Optionally, the individual, cooled steaks can be treated with a marinade, sauce or spice mixture prior to packaging.

In some embodiments, the meat may be coated with a dry marinade prior to cooking, which marinade is adapted to absorb water released from the meat during cooking to form a wet marinade. Said dry marinade may include a thickening agent, such, for example, as corn starch.

In a particularly preferred aspect of the present invention, the body of meat may be cut as necessary after tumbling into portions of desired weight; optionally treated with one or more ingredients selected from marinades, seasonings, spices and organoleptic agents; vacuum-packed; and thereafter cooked as mentioned above in the vacuum packaging. Said portions may be individual-sized meat portions. Said portions of desired size may be packaged individually or collectively to provide a predetermined number in each pack. Said portions may be packed into vacuum pouches. After cooking, the pouches are allowed to cool and may then be labelled for retail. Those skilled in the art will appreciate that by cooking the steaks in their final packaging under vacuum, the risk of microbial recontamination of the meat is eliminated, thereby obviating the need to provide a "high risk" sterile handling area which is expensive to maintain.

Furthermore, said portions may be treated prior to sealing and cooking with a marinade, preferably a dry marinade, comprising a thickening agent which is adapted to absorb water subsequently released during cooking to form a wet marinade.

All types of meat, including pork, beef, turkey and chicken can be processed using the process of the present invention. Said body of meat may comprise one or more natural cuts of meat from an animal, such as whole muscle cuts, chops and steaks as well as reformed (or "reconstituted") steaks. In particular, the process of the invention can be applied to extruded whole muscle or extended meat, such as poultry meat. Said body of meat may alternatively comprise an assemblage of chunks and/or slices of whole muscle or extended meat formed into a shaped body by moulding under pressure, preferably at low temperature. Following is a description by way of example only with reference to the accompanying drawing of embodiments of the present invention in effect. In the drawings: Figure 1 is a flow diagram of a process in accordance with a first embodiment of the present invention.

Figure 2 is a flow diagram of another process in accordance with a second embodiment of the present invention. Figure 3 is a flow diagram of yet another process in accordance with a third embodiment of the present invention.

Example 1 With reference to Figure 1, a body of meat is provided of a size and weight sufficient to provide at least two, and preferably more, individual steak portions. Said meat may be selected from pork, beef, turkey or chicken meat, and the meat may comprise a natural, "butcher's" cut of meat, e.g. whole muscle meat, or reformed meat. For the purpose of this example, however, a cut of whole muscle, turkey breast meat is employed. Said meat piece is injected with a "spicy brine" solution using a Schroder Pokelinjektor N120, available from Helmut Schroder GmbH of Esch 11, 33824 Werther, Germany. The spicy brine is injected into the turkey breast meat at a pressure of about 1.3 bar, and the amount of spicy brine added is about 25% by weight of the meat portion. Said spicy brine is formulated as follows

Water 91.1%wt

Salt 3.0%wt Barbecue flavour 0.3%wt

Liquid paprika 0.9%wt

Smoke flavour 0.4%wt

Garlic extract 0.1%wt

Green pepper 0.2%wt Dextrose 4 . 0%wt

100%wt

The injected meat is then gently tumbled for about 30 minutes to distribute the spicy brine substantially uniformly throughout the meat body.

After tumbling, the meat body is packaged into a pouch or casing, or placed in a mould. Said pouch, casing or mould may be perforated to allow water cooked-out of the meat to escape. The product is then cooked for sufficient time to provide a core temperature in the range 66 to 71°C.

The meat product is then transferred to a sterile "high risk" area H, where it is allowed to cool, and the pouch casing or mould is removed. After cooling, the meat body is cut into individual steaks, and optional marinade or spice mixtures may be added to the meat, which is then packaged and labelled.

Example 2

With reference to Figure 2, a body of meat is injected with spicy brine and gently tumbled as described in Example 1 above.

After tumbling, the meat is cut into individual steaks, and then cooked using dry heat or a full-steam environment to provide a core temperature within the meat of 66 to 71°C. The meat is then transferred to a high risk area and allowed to cool. After cooling, additional marinade or spice mixtures may be added to the meat, which is then packaged and labelled as before.

Example 3

A body of whole muscle turkey meat is injected with about 10% wt spicy brine and gently tumbled as described above in Example 1. In this example, said spicy brine is formulated at follows :-

Water 88,50%wt Salt 5,50%wt Liquid paprika 0,90%wt

Smoke flavour 0,50%wt

Garlic extract 0,10%wt

Green pepper 0,20%wt

Lemon flavour 0,30%wt

Dextrose 4,00%wt

100,00%wt Injection rate 10%wt addition. After tumbling, the meat is cut into individual portions and coated with a dry marinade composed of spices and thickeners. Said marinade has the following formulation:-

Mesquito glaze 70%wt

Corn starch 30%wt

The marinade is applied to the steaks at a rate of about 50g of glaze per 1,-kgs steak. A suitable mesquito glaze comprising spices, sugars, modified starch, salt and vegetable fat is available commercially from Arnold/Versteegen

The coated steaks are then packed in vacuum packages suitable for retail and are cooked in the pouches according to the following regime :- Step 1: Cooking at 50°C to a core temperature of about 0°C.

Step 2: Cooking at 65°C to a core temperature of about 60°C. Step 3: Cooking at 75°C to a final core temperature of 72°C.

The thickener binds the water released during cooking, and the dry marinade turns into a wet marinade coating the steaks.

After cooking the pouches are allowed to cool and are then labelled and dispatched.

Example 4 A body of whole muscle turkey meat is injected with about 10% wt of mild yogurt spicy brine and gently tumbled in accordance with Example 3 above. In this example, the spicy brine is formulated as follows :-

Mild yogurt (pH -5. 1 ) 75, - kg

Salt 11 , - kg

Green pepper 1 , 3 kg Whey powder 1,7 kg

Seasoning (Jumbo Brat, Raps) 11,- kg

100,- kg

The injected meat is then gently tumbled, coated with a dry marinade mix, packaged, cooked/pasteurised, cooled and labelled as described in Example 3.

By adding about 10-25% by weight spicy brine to a turkey breast meat body as described in the above examples, the water-to-meat protein ratio of the product is increased to above . The amount of water added is approximately equal to the amount of water lost during subsequent cooking, so that when the final product is re-heated before consumption, it has a similar tenderness and juiciness to a previously uncooked piece of fresh meat. The presence of salt in the brine assists in retaining the added water in the meat. On cooking, the water-to-meat protein ratio is reduced to 4 or less. Cooking of the meat body to a core temperature of 66 to 71°C is sufficient to kill substantially all meat flora, including salmonella and listeria, thus improving the shelf-life and food safety of the product of the invention. Said meat product may be reheated by barbecuing, grilling, roasting or frying.

In accordance with Examples 3 and 4, the steaks are pre-cooked in their final packaging under vacuum. Thus the risk of recontamination of the meat after cooking is eliminated without requiring special sterile handling facilities.

Claims

Claims : -

1. A process for making a pre-cooked meat product, which process comprises providing a body of fresh meat, injecting said body with brine, tumbling said body and thereafter cooking said body to a core temperature in the range of 65-75°C to pasteurize the meat.

2. A process as claimed in claim 1, comprising injecting said body with brine using a multi-needle in ector.

3. A process as claimed in claim 1 or claim 2, comprising adding sufficient brine to the meat body to substantially compensate the water lost on cooking.

4. A process as claimed in claim 1, claim 2 or claim 3, comprising injecting said meat body with about 10-40% weight brine.

5. A process as claimed in any preceding claim wherein after brine-injection, the water-to-meat protein ratio of the meat product is greater than 4.

6. A process as claimed in any preceding claim, wherein after cooking the water-to-meat protein ratio is less than or equal to 4.

7. A process as claimed in any preceding claim, wherein the brine comprises 1 to 5% weight salt.

8. A process as claimed in any preceding claim, wherein said brine comprises a liquid fermented milk product having a pH selected such that, when mixed with the meat, the overall pH of the product is at least 5.0.

9. A process as claimed in claim 8, wherein said fermented milk product has a pH in the range 4.8 - 5.1.

10. A process as claimed in claim 8 or claim 9, wherein said fermented milk product is selected from one or more of mild yoghurt, buttermilk, soured cream milk, sour milk and fermented whey.

11. A process as claimed in any of claims 8 to 10, wherein said brine comprises mild yoghurt.

12. A process as claimed in any preceding claim, wherein said brine comprises up to about 10% weight other flavourings.

13. A process as claimed in any preceding claim wherein said injected body of meat is tumbled gently for 15 to 25 minutes.

14. A process as claimed in any preceding claim wherein the meat is cooked to a final core temperature in the range of 66-72°C.

15. A process as claimed in any preceding claim wherein the core temperature of the meat body is increased step-wise by increasing the cooking temperature in a series of stages.

16. A process as claimed in claim 15, wherein each cooking stage is calculated to elevate the core temperature of the meat by about 5 to 15°C.

17. A process as claimed in any preceding claim wherein the body of meat comprises a single portion size steak which is cooked individually in a full steam environment or with dry heat.

18. A process as claimed in any of claims 1 to 16, wherein said body of meat comprises sufficient meat to make two or more steaks, said meat body being wrapped, packaged or placed in a mould prior to cooking and then removed from said wrapping, packaging or mould after cooking and cut into individual steak portions.

19. A process as claimed in claim 17 or 18, wherein the meat product is allowed to cool in a "high-risk" sterile environment before final packaging.

20. A process as claimed in claim 19, wherein the individual, cooled steaks are treated with a marinade, sauce or spice mixture prior to packaging.

21. A process as claimed in any of claims 1 to 16, comprising: cutting said body of meat as necessary after tumbling into portions of desired weight; vacuum-packaging said portions; and thereafter cooking said portions in said vacuum-packaging.

22. A process as claimed in claim 21, wherein after cooking the vacuum packaging is allowed to cool and is then labelled.

23. A process a claimed in any preceding claim, wherein said meat portions are treated prior to cooking with one or more ingredients selected from the marinade, seasonings, spices and organoleptic agents.

24. A process as claimed in any preceding claims, wherein said meat is treated prior to cooking with a marinade comprising a thickening agent adapted to absorb water released during cooking.

25. A process as claimed in claim 24, wherein the meat portions are treated with a dry marinade adapted to absorb water lost on cooking to form a wet marinade .

26. A pre-cooked meat product that is manufactured in accordance with a process as claimed in any of claims 1 to 25.