GB2149639A - Food product and method and apparatus for its manufacture - Google Patents

Abstract

A proteinaceous food product particularly a period is made by forming a finely divided mix or emulsion containing proteinaceous materials, adding a water soluble gel-forming agent and forming the mix or emulsion into discrete pieces. Before and/or after forming the pieces the mix or emulsion is treated with a calcium salt. The process is characterized in that the mix or emulsion contains a quantity of dry denatured greaves. Apparatus for carrying out the process is also disclosed.

Description

SPECIFICATION Food product and method and apparatus for its mariufacture Thekinvention relatesto a food product and also to a meEodiancEa,paratusfor its manufacture. The invention is particuiariy concerned with the manufacture of a prnteinaceousfood product in the form of discrete shape-retaining pieces or chunks. The product of the invention is particularly suitable for use as a pet food, particularly a dog or cat food, but is not restricted to such use and has other possible uses.

There are known processesforthe manufacture of proteinaceous food products which have a chunky meat appearance and which are particularly suitable for canning as pet foods. One method of manufacturing formed meat products which subsequently may be canned isto form an emulsion of animal and/or vegetable proteins and subsequently to heat-set the proteins into chunks. The use of heat-setting has a number of disadvantages which include excessive water loss and the loss of soluble proteins. There is also the possibility that heat treatment renders the food less acceptable to animals. Methods of coldforming food products into shape-retaining chunks using a jelled calcium alginate are described in U.K.

Patent Specification No. 1,474,629 and U.S. Patent Specification No.4,348,418.

British Patent Specification No. 1,474,629 discloses and claims a method of cold-forming a proteinaceous food product in the form of discrete shape-retaining pieces which comprises forming a finely divided mix or emulsion containing animal and/or vegetable proteinaceous materials, incorporating a water solu ble alginate in said mixor emulsion,forming the said mixoremulsion into pieces ofthe desired shape and subsequently treating the formed pieces with an aqueous solution ofwatersolublecalcium salt. The British Patent Specification also described the incorporation of a water-insoluble calcium salt into the alginate containing mix or emulsion.In this case the aqueous solution of a water-soluble calcium salt also contains an edible acid. Aftertreatmentwith a solution containing calcium ions, a gelled calcium alginate skin is formed around each piece to encapsulate the proteinaceous material and retain the discrete shape ofthe piece.

It has beenfoundthatfood pieces prepared in accordance with the method of British Patent Specification No. 1,474,629 have a soft, sticky, pasty interior and do not closely resemble meat chunks. In the examples described in Patent Specification No.

1,474,629 the mix contains cereals and/or refined meat meal, which help to absorb water present in the mix, but detractfrom the desired consistency and taste of the product W' tentSpeciftcation No. 4,348,418 discloses and claims a method offorming food products in the fonm of shaperetaining pieces which comprise the steps of:: (a) producing an aqueous slurry of comminuted food material having a water-soluble alginate salt dissolved therein, (b) producing a slurry of a sparingly water-soluble calcium salt including as a retarding agent a member selected from the group consisting of sugar, a monohydricalcohol and a polyhydricalcohol, (c) mixing the slurries of step (a) and (b) for a time period of less than 30 seconds, (d) allowing the resulting mixture of step (c) to gel; and; (e) cutting into piecesthe product of step (d), said water soluble alginate salt being present in an amount of from 0.3 to 5.0 percent by weight of said product.

In practice it has been found that improved chunks prepared by the above process do not have the necessary firm fibrous texture of meat, and are less palatable to animals than meat.

We have surprisingly found that by incorporating dry denatured greaves in the emulsified mix a cold formed chunk may be prepared which has the consistency and texture of solid meat, and which is highly palatable to animals and is also highly nutrious.

Accordingly, we provide a process for preparing a proteinaceous food product in the form of discrete shape-retaining pieces which comprises forming a finely divided mix or emulsion containing proteinaceous materials, adding a water soluble gell forming material to said mix or emulsion, forming the mix or emulsion into discrete pieces and before and/or afterforming said pieces treating the mix or emulsion with a calcium salt, characterised in thatthe mix or emulsion contains a quantity of dry denatured greaves. Suitably, the amount of greaves present in the mixture is between 7 and 30% by weight, and preferably is between 10 and 15% byweight.

The water soluble gell-forming agent may be a water soluble alginate, for example sodium alginate or a water soluble pectin. Suitably, the formed pieces containing the water soluble alginate are dipped in a bath containing an aqeous solution of a water soluble calcium salt. Alternatively, or in addition, it is possible to add a sparingly soluble calcium salt e.g. calcium sulphate, into the emulsion or mix before formation of the pieces. The calcium reacts slowly with the setting agent and causes the subsequently formed pieces to set into shape-retaining chunks.

The gell-forming agent may comprise a water soluble pectin alone. The pectin may be either a low methoxy pectin ora high methoxy pectin. If a low methoxy pectin is used then treatment with calcium ions will be required for gell formation. If a high methoxy pectin is used it is necessary to use sugar to causethe pectin to gel. The sugar may be added to the other ingredients forming the emulsion.

In accordance with a further embodiment of the invention, the gell-forming agents comprises a mixture of an alginate and a pectin. If, the pectin used is a low methoxy pectin both the alginate and pectin are caused to gell by contact with a calcium salt. We have surpisinglyfound that by using such a mixture, the pectin will acttofirm up the centre ofthe chunkwhile the alginate forms a gell skin around the outside ofthe The drawing(s) originally filed were informal and the print here reproduced is taken from a later filed formal copy.

chuck. The reason forth is is that the alginate reacts quickly with the calcium to form the outer skin, while the pectin reacts more slowly, but continues to set aftertheformation ofthe outer skin to firm the centre ofthe chunk. This setting will be accelerated if the chunksare heated during canning. If a high methoxy pectin is used with the alginate, it is necessary to add sugar to the emulsion, butthis has the advantage that less calcium salt is required. Another advantage of using a mixture of alginate and pectin isthatthe dwell time in the bath of solution of calcium salt is reduced thus speeding-up the process.

Ithas beenfoundthat byusing dry denatured greavesthe mixture may contain a relatively high proportion ofwaterwhich is absorbed by the dry denatured greaves andthe drygreaves also givethe chunks an improved meaty texture and flavour, and is highly nutrious. It has also been found advantageous to use guar gum in the mixture. It has been found that guar gum stiffens the mixture, increases viscosity and allows the material to move more easily through the forming apparatus. It also assists in retaining moisture in the formed pieces especially if the pieces are canned.

The examples described in U.S. Patent Specification No.4,348,418 disclose the use of wet greaves.

However, these do not offer the same advantages as the dry denatured greaves ofthe invention. The dry denatured greaves ofthe invention is prepared by dry cooking fatty animal tissue, drying the cooked tissue and while the tissue is still hot extracting thefatfrom the tissue using mechanical pressure. The residual dry denatured greaves is crispy with a good aroma and a palatable taste. It also has a long shelf life and can be stored without refrigeration. In contrast, wet greaves is formed by extracting the fat by rendering while steam cooking. The water moisture is retained in the residual tissue. Wet greaves has a bland taste and aroma. Further ittendsto become rancid very quickly and must be stored under refrigeration.

In a preferred method according to the invention the proteinaceous material including dry denatured greaves is formed into an emulsion and is pumped through a forming machine which includes a forming die comprising at least one reciprocating apertured plate which moves relative to a second apertu red plate suchthatthe emulsified material passing through the apertures in the two plates is formed into discrete chunk shaped pieces. Preferably, the chunks are collected in a bath containing an aqeous solution of a water soluble calcium salt The chunks float in the bath and are conveyed along the bath by means of a plurality of paddles to preventthe chunks from accumulating into a solid mass.

In accordance with a second aspect, the invention provides apparatus for prepa ring a proteinaceous food product intheform of discrete shape-retaining pieces or chunks, the apparatus comprising means for holding a mixture of comminuted proteinaceous materials, a pump or other suitable means for conveying the emulsion to a forming machine, the forming macing including a die intheform ofatleast one reciprocating plate containing a plurality of apertures which is movable relative to at least a second plate also containing a plurality of apertured, the apertures in one plate coinciding with the apertures in the other plate during the relative movements of the plate whereby the emulsion is extruded in the form of discrete pieces which form into shaperetaining chunks.

One embodiment of a method and apparatus of the invention is hereinafter described with reference to the accompanying drawings, wherein: Fig. is a side elevation of a commercially available meat mixing machine; Fig. 2 is a side elevation offorming apparatus of the invention; and Fig. 3 shows a detail of the apparatus of Fig. 2.

Referring to the drawings, a mixture typically containing dry denatured greaves, crushed bone, liver, sodium alginate, guar gum, sodium benzoate and water is finely mixed in an automatic meat mixing machine 1, as shown in Fig. 1. This machine is commercially available from K. Schnell and carries out the functions of mixing the ingredients, bowl chopping and emulsifying. Mixing, chopping and emulsifying are preferably carried out under part-vacuum. This allows waterto be brought into the mixture more quickly butyet prevents a large amount of air being incorporated in the emulsion. The presence of a small amount of air is desirable to enable the formed chunks to float as described below.The mixture is formed into an emulsion in the mixing machine and is passed into a holdingtankintheform of a hopper2 (see Fig. 2).

Fromtheholdingtanktheemulsion isfedtothe hopper3ofa monopump4.Thepump4pumpsthe emulsion, under a pressure of about 20 to 25 p.s.i., through a pipe 5to a forming die 6. The pipe 5 is provided with a pressure-relief valve (not shown). If there is a build up of pressure in pipe 5 the relief valve will open to recycle the emulsion to the hopper 3.

The die 6forformingthe chunks is shown in more detail in Figure 3. It comprises a fixed die plate 7 formed with a plurality of apertures 8. A second plate 9, having apertures 10, isslidable horizontally relative to the fixed plate 7. The plate 9 is moved by means of a reciprocating drive of an electric motor 11. During the travel ofthe plate 9 relative to the fixed plate 7, the holesin each plate will coincide to allow emulsion to be extruded in the form of pieces or blobs. The size of the piece extruded can be determined by controlling the speed of reciprocation of the plate 9 and the pressure in pipe 5. These parameters will largely determine the length of the piece extruded. The width or diameter of the piece extruded is determined by the size the holes in the plateandthese may be changed as desired.

The extruded pieces fall into a bath 12. The bath contains a solution of a water soluble calcium salt. The pieces or chunks float on the surface ofthe solution and are conveyed along the bath by means of paddles 13 which are driven by an endless chain 14.

The gelled chunks are removed from the bath for further processing.

The formed chunks may,forexample, be frozen or canned. Ifthe chunks are canned for use as a dog orcat food the chunks are preferably mixed with a textured vegetable protein, e.g. a soya protein. A matrix is also added to the canned chunks. The matrix may comprise a gravy made from minced meats. Suitably a heat-setting gel is added which is caused to set when heat is applied during canning.

The invention is further illustrated by the following examples, which are for exemplification only and are not intended to be limiting. All parts shown are parts by weight.

EXAMPLE 1 A mixture containing: Drygreaves 12% Crushed bone 12% Liver 6% Sodium alginate 1.2% Guargum 0.8% Sodium benzoate 0.3% Water & ye 67.7% was mixed using a chopping action for 30 secs- 1 minute and passed through a 3mm plate. The slurry was passed through a chunk forming machine under pressure and the chunks were allowed to drop into a bath containing calcium chloride (1 - 20%). The chunks were conveyed along the bath using paddles and a belt conveyor. After 10 mins. chunks made a skin strong enough to withstand processing. After2 hours the centres of chunks had solidified.

EXAMPLE 2 A mixture containing: Drygreaves 15% Bone 10% Liver 5% Sodium alginate 1.2% Guargum 0.8% Water 66.2% Sodium Benzoate 0.3% Calcium Sulphate 0.5% Tetra sodium pyrophosphate 0.025% was prepared as in Example 1.

EXAMPLE 3 A mixture was prepared containing: Dry denatured greaves 15% Crushed bone 10% Liver 5% Amidated Low Methoxyl Pectin 2% GuarGum 2% Water & ye 66% The mixturewas treated as in Example 1. The pectin requires only a brief contact with the calcium choloride forsetting to begin so that the dwell time in the bath can be low. The pectin has a slow response to calcium so that setting continues slowly on removal from the bath. If the chunks are canned setting will be accelerated by heating during canning.

EXAMPLE 4 A mixture containing: Dry denatured greaves 12% Crushed bone 12% Liver 6% Sodium alginate 1.0% L.M. Pectin 0.5% GuarGum 0.8% Sodium benzoate 0.3% Water & ye 67.4% The mixture was treated as in Example 1. The alginate reacted quickly with the calcium to form a skin on the outside ofthe chunk, while the pectin reacted more slowly within the chunk to form up the centre of the chunk.

EXAMPLE 5 A mixture containing: Drygreaves 15% Bone 10% Liver 5% Sodium alginate 1.2% Guargum 0.8% Water 66.2% Sodium Benzoate 0.3% Calcium Sulphate 0.5% Tetra sodium pyrophosphate 0.025% was passed through a 3 cm plate into trays and allowed to set (typically 5 minutes to 1 hour). Slabs were diced into suitable shapes.

EXAMPLE 6 A mixture containing: Drygreaves 20% GuarGum 2% Sodium alginate 1.5% Sodium benzoate 0.3% Water 76.2% was treated as in Example 1.

EXAMPLE 7 A mixture containing: Drygreaves 20% GuarGum 2% Sodium alginate 1.5% Sodium benzoate 0.3% Water 76.2% was treated as described in Example 5.

Claims (24)

1. A process for preparing a proteinaceous food product in the form of discrete shape-retaining pieces which comprises forming a finely divided mix or emulsion containing proteinaceous materials, adding awatersoluble gel-forming agent to said mix or emulsion,formingthe mix or emulsion into discrete pieces and before and/or afterforming said pieces, treating the mix or emulsion with a calcium salt, characterized in that the mix or emulsion contains a quantity of dry denatured greaves.

2. A process as claimed in claim 1 wherein the amount of greaves present in the mixture is between 7 and 30% byweight.

3. A process as claimed in claim 2 wherein the amount of greaves present in the mixture is between 10 and 15% byweight.

4. A process as claimed in any preceding claim wherein the water-soluble gel-forming agent is a water-soluble alginate.

5. A process a claimed in claim wherein the water-soluble alginate is sodium alginate.

6. A process as claimed in any preceding claim wherein the formed pieces are dipped in a bath containing an aqueous solution of a water-soluble calcium salt.

7. A process as claimed in any preceding claim wherein a sparingly soluble calcium salt is added to the mix or emulsion before the formation ofthe pieces.

8. A process as claimed in claim 10 wherein the sparingly soluble calcium salt is calcium sulphate.

9. A process as claimed in any one of claims 1 to 3 wherein the water-soluble gel-forming agent is a water-soluble pectin.

10. A process as claimed in claim 9 wherein the water-soluble pectin is a low methoxy pectin.

11. A process as claimed in claim 9 wherein the water-soluble pectin is a high methoxy pectin.

12. Aprocessasclaimed in claim 1 whereinthe gel-forming agent comprises a mixtureofanalginate and a pectin.

13. A process as claimed in claim 12 wherein the alginate and low methoxy pectin are caused to gel by contact with a calcium salt.

14. Aprocessasclaimed ineitherofolaims 11 or 12wherein the high methoxy pectin is caused to gel by the addition of sugar.

15. A process as claimed in claim 12 wherein the formation of a gel is accelerated by heating.

16. A process as claimed in any preceding claim wherein guar gum is used in the mix or emulsion.

17. A process according to anyone ofthe preceding claims wherein the proteinaceous material including dry denatured greaves is formed into an emulsion and is pumped through aforming machinewhich includes a forming die comprising at least one reciprocating apertured plate such that emulsified material passing through the apertures in the two plates is formed into discrete chunk-shaped pieces.

18. A process as claimed in claim 18 wherein the chunk-shaped pieces are collected in a bath containing an aqueous solution ofa water-soluble calcium salt and the chunks floating in the bath are conveyed along the bath by means of a plurality of paddles.

19. An apparatusforpreparing a proteinaceous food product in the form of discrete shape-retaining pieces or chunks comprising means for holding a mixture ofcommunited proteinaceous materials, a means for conveying the mixture to a forming machine, the forming machine including a die in the form of at least one reciprocating plate containing a plurality ofapertureswhich is movable relative to at least a second plate also containing a plurality of apertures, the apertures in one plate coinciding with the apertures in the other plate during the relative movements of the plate whereby the emulsion is extruded in the form of discrete pieces which form into shape-retaining chunks.

20. A proteinaceous food product suitable for use as a petfood comprising a mixture of dry denatured greaves, crushed bone, liver and guar gum, in the form of discrete, gelled shape-retaining chunks, in which the gel has been formed by the action of a water soluble gel-forming agent.

21. An apparatusfor preparing a proteinaceous food product substantially as described herein with reference to the accompanying drawings.

22. Aproceesforpreparing a proteinaceous food product substantially as described herein with reference to the Examples.

23. A proteinaceous food product substantially as described herein with reference to the Examples.

24. Aproteinaceousfood productwheneverprepared by a process as claimed in any one of claims 1 to 19 and claim 22.