FOODSTUFF

Abstract: The invention provides a canned foodstuff comprising discrete chunks, the chunks comprising a food material and being substantially free of intervening liquid, gel or other matrix material. Preferably, the chunks are of a leavened foodstuff comprising a gelled mixture comprising meat protein. The invention also provides a method of making a foodstuff comprising forming a mixture of meat protein and a gelling system and leavening the mixture while gelling it.

Description: FOODSTUFF The present invention relates to a novel foodstuff, and more particularly to a petfood, and to methods of making the novel foodstuff. There are three different types of canned petfood widely available at present. The first consists of meat chunks in a thick gravy; the second consists of meat chunks in a jelly; and the third consists of meat chunks in a meat loaf or mousse. The present invention is a novel style of canned pet food, and a method of making it. In accordance with the present invention, there is provided a canned foodstuff comprising discrete chunks of a gelled mixture comprising meat protein, the chunks having a sponge-like internal texture and being substantially free of intervening liquid, gel or other matrix material. Preferably, there is no more than 10% by weight of the can contents intervening liquid, gel or other matrix material. In the can each chunk is supported by and in direct contact with neighbouring chunks. The absence of a surrounding medium enables the chunks to be emptied from the can cleanly, leaving the inside substantially free of unwanted residues. Furthermore, on removing the contents from the can, the discrete chunks are free- running and separate easily. This is quite different to the petfoods with meat chunks in jelly or mousse which must be mashed, or at least broken up, to produce bite-sized pieces. It has been established from feeding tests analysed using conventional mapping techniques that groups of one species of animal, such as cats, having common feeding preferences can be identified. Feeding tests conducted with canned foodstuffs according to the present invention indicate that some of these groups of cats show a marked preference for the foodstuffs of the present invention over conventional canned petfoods, which typically contain around 20% by weight of can contents of free liquid or gel. Preferably, the chunks comprise between 65 and 85%, preferably between 70 and 80%, by weight water. In accordance with a second aspect of the invention there is provided a method of making a food stuff comprising: forming a mixture of meat protein and a gelling system and leavening the mixture while gelling it. Preferably, a chemical leavening agent is included in the mixture and is activated while the mixture is gelled. Alternatively, leavening may be by gas injection, fermentation and whipping. If a chemical leavening agent is employed it is preferably added at from 0.1% to 1.5%, more preferably from 0.3% to 0.8%, by weight of meat protein. As the mixture gels, the chemical leavening agent releases gas giving rise to an expanded product having a sponge-like texture. Preferably, the gelling system is thermally activated, although other gelling techniques may be employed by using, for example, an alginate gel. A preferred thermally activated gelling systems comprise starch or protein. In one embodiment of the seςond aspect of the invention, a chemical leavening agent is activated by heat. A preferred thermally-activated chemical leavening agent for nutritional purposes is potassium hydrogen carbonate. In an alternative embodiment, the chemical leavening agent is activated by a change in pH, in which case the preferred chemical leavening agent is calcium carbonate. The change in pH may be effected by adding a slow release acid such as sodium aluminium phosphate to the mixture. If whipping (mechanical aeration or gas injection) is employed to leaven the mixture, it is preferred that a protein stabiliser such as eggwhite or blood plasma is added to the mixture, preferably in an amount of from 1% to 5% by weight of meat protein. In a preferred method using fermentation to leaven the mixture, yeast is blended through a mixture of meat purέe and wheat flour. The mixture is allowed to stand to achieve the onset of fermentation, after which it is heat gelled and further treated, if necessary. Preferably, chunks of the gelled mixture are sealed in a container with some liquid or gel, and the contents of the container heated so that substantially all the liquid or gel is absorbed by the chunks. Heating the container results in absorption of the liquid or gel -and causes the chunks to expand. In an especially preferred arrangement the gelled mixture is cut into chunks which are then sealed in the container; the expansion effect during heating can be used to produce a sealed container filled to the brim with chunks which are pressing against each other. The amount of liquid or gel sealed into the can with the chunks can be such that after absorption of the liquid or gel there is no free liquid or gel in the can. Alternatively, the amount of liquid or gel can be such that a small amount of free liquid or gel remains in the can after absorption, there being preferably no more than 10%, more preferably no more than 5%, and most preferably no more than 2% by weight of can contents of free liquid or gel. In accordance with another aspect of this invention, there is provided a leavened foodstuff comprising a gelled mixture comprising meat protein. Preferably, the gelled mixture further comprises starch. In one embodiment, the gelled mixture contains at least 60% by weight water. A semi-moist product having a water content of about 30% is also envisaged. Alternatively, dehydrating the foodstuff enables the water content of the gelled mixture to be reduced to between 5 and 10% by weight. The leavened nature of the foodstuff facilitates water removal and subsequent rehydration when the foodstuff is to be used. Dehydration can be used to preserve the foodstuff for long periods. In an especially preferred form, the leavened foodstuff has a surface texture resembling that of cooked meat, particularly a red meat. The presence of wrinkle-like features on the surface of the foodstuff gives the impression of a natural product. The invention will be understood in greater detail from the following examples of specific embodiments thereof: Example 1 A foodstuff is made as follows: A dough is formed by mixing 85g of meat puree with I5g of flour and about 0.5g of potassium hydrogen carbonate. The mixture is heated to a centre temperature of 90°C to initiate gelling and the release of carbon dioxide gas, while being shaped into a rope. The gas evolves as the mixture gels results in a leavened product. When firm, the rope is cut into bite-sized chunks. The chunks contain about 60% by weight water and, on cooling, develop a wrinkled texture reminiscent of cooked meat on surfaces exposed in the rope. About 210g of the chunks are sealed inside a 400ml can with about 160g of water. The canned foodstuff is then retorted at 129°C for 59 minutes, thus ensuring that the meat derivatives are fully cooked. During retorting, the chunks absorb all the free liquid and expand to fill any spaces in the can. When the can is opened, the impression gained is one of a container packed full of individual chunks. On removing the contents from the can, the chunks separate easily, there being no binder between chunks. The chunks have a water content between 75 and 80 weight percent and a surface texture resembling cooked meat, and the inside of the can is free from unwanted residues. Example 2 An alternative foodstuff is made using 0.5g of sodium bicarbonate in place of the potassium hydrogen carbonate. 0.5g of a slow release acid, sodium aluminium phosphate, is added to the mixture so as to change the pH during gelling. As the acidity increases, the sodium bicarbonate decomposes to release carbon dioxide giving rise to a leavened product. When firm, the foodstuff is further processed in exactly the same way as in Example 1. Example 3 A foodstuff is made in the same way as in Example 1, except that about 190g of the chunks are sealed in the can with about 180g of water. Not all the water is absorbed by the chunks during processing. When the processed can is opened, the impression gained is of a container packed full of individual chunks with a glossy coating of gravy, having a desirable appearance.

Claims: C AIMS 1. A canned foodstuff comprising discrete chunks, the chunks comprising a food material and being substantially free of intervening liquid, gel or other matrix material. 2. A canned foodstuff according to claim 1 containing no more than 10% by weight of the can contents intervening liquid, gel or other matrix material. 3. A canned foodstuff according to claim 1 or 2 in which the chunks are of a gelled mixture comprising meat protein. 4. A canned foodstuff according to claim 1, 2 or 3 in which the chunks have a sponge-like internal texture. 5. A canned foodstuff according to any of claims 1 to 4 in which at least some of the pores in chunks contain liquid. 6. A canned foodstuff according to any of claims 1 to 5 in which the chunks comprise between 65 and 85%, preferably between 70 and 80%, by weight water. 7. A canned petfood according to any of claims 1 to 6 for which at least one group of cats having a common feeding preference for conventional cat foodstuffs shows a preference over conventional canned petfood for cats. 8. A leavened foodstuff comprising a gelled mixture comprising meat protein. 9. A leavened foodstuff according to claim 8 in which the gelled mixture further comprises starch. 10. A leavened foodstuff according to claim 8 or 9 in which the gelled mixture further comprises residue from an activated chemical leavening agent. 11. A leavened foodstuff according to claim 5, 6 or 7 in which the gelled mixture comprises at least 5% by weight water. 12. A leavened foodstuff according to claim 11 in which the gelled mixture comprises at leaat 30% by weight water. 13. A leavened foodstuff according to claim 12 in which the gelled mixture comprises at least 60% by weight water. 14. A dehydrated leavened foodstuff according any of claim 8 to 11 in which the gelled mixture comprises no more than 10% by weight water. 15. A leavened foodstuff according to any of claims 8 to 14 having a surface texture resembling cooked meat. 16. A canned foodstuff according to any of claims 1 to 7 wherein the chunks are according to any of claims 8 to 13 or to claim 15 when dependent from any of claims 8 to 13. 17. A method of making a foodstuff comprising: forming a mixture of meat protein and a gelling system and leavening the mixture while gelling it. 18. A method according to claim 17 in which the mixture is gelled by heating. 19. A method according to claim 18 in which the gelling system comprises starch. 20. A method according to any of claims 17 to 20 which comprises forming a mixture of meat protein, a gelling system and a chemical leavening agent, and gelling the mixture while activating the chemical leavening agent. 21. A method according to claim 20 in which the chemical leavening agent is added in an amount of from 0.1% to 1.5% by weight of meat protein. 22. A method according to claim 21 in which the chemical leavening agent is added in an amount of from 0.3% to 0.8% by weight of meat protein. 23. A method according to claim 20, 21 or 22 in which the chemical leavening agent is activated by heating. 24. A method according to any of claims 20 to 23 in which the chemical leavening agent is a hydrogen carbonate of an alkali metal. 25. A method according to claim 24 in which the alkali metal is potassium. 26. A method according to any of claims 20 to 25 in which the chemical leavening agent is activated by a change in pH. 27. A method according to claim 26 in which the chemical leavening agent is calcium carbonate. 28. A method according to claim 26 or 27 in which the change in pH is effected by a slow release acid which is added to the mixture. 29. A method according to any of claims 17 to 28 further comprising: sealing the gelled mixture in a container with a liquid; and heating the contents of the container so that the liquid is absorbed by the gelled mixture. 30. A method according to claim 29 further comprising cutting the gelled mixture into chunks before sealing in the container. 31. A canned petfood for which at least one group of cats having a common feeding preference for conventional cat foodstuffs shows a preference over conventional canned petfood for cats. 32. A method of making a foodstuff substantially as hereinbefore described. 33. A leavened foodstuff substantially as hereinbefore described. 34. A canned foodstuff substantially as hereinbefore described.

Inventors: HARFORD STEPHEN, MUSSON GARY DAVID, SPEIRS CHARLES IVIE, WALKER RICHARD JAMES, HARFORD, STEPHEN, MUSSON, GARY, DAVID, SPEIRS, CHARLES, IVIE, WALKER, RICHARD, JAMES
Applicants: HARFORD STEPHEN, MARS UK LTD, MUSSON GARY DAVID, SPEIRS CHARLES IVIE, WALKER RICHARD JAMES, HARFORD, STEPHEN, MARS U.K. LIMITED, MUSSON, GARY, DAVID, SPEIRS, CHARLES, IVIE, WALKER, RICHARD, JAMES
Application year: 1996
Main classification: A23J3
IPC codes: A23K1, A23L1