CA2132366C

CA2132366C - Process and an arrangement for the production of a co-extruded product and the product obtained

Info

Publication number: CA2132366C
Application number: CA002132366A
Authority: CA
Inventors: Pierre Dupart; Osvaldo Geromini; Minas Zafiropoulos
Original assignee: Societe des Produits Nestle SA
Current assignee: Societe des Produits Nestle SA
Priority date: 1993-10-08
Filing date: 1994-09-19
Publication date: 2004-07-13
Anticipated expiration: 2014-09-19
Also published as: GR3034342T3; AU7296094A; ATE193804T1; CA2132366A1; NO943750L; EP0647410B1; NO943750D0; DE69424913T2; ZA947020B; JPH07184621A; NO310956B1; JP3665372B2; NZ264540A; AU697220B2; DE69424913D1; ES2148262T3; PT647410E; DK0647410T3; EP0647410A1

Abstract

The invention relates to a process for the production of a co-extruded product comprising an outer envelope arid a filling. The arrangement comprises an extruder (1), a co-extrusion head (2), a moulding unit (4) and a cooling system (21).

Description

z~.3~366 This invention relates to a process and an arrange-ment for the production of a ca-extruded product compri-sing an outer envelope and a filling. The invention also relates to the co-extruded product comprising an outer envelope of uniform thickness and a liquid, semi-liquid or powder-form inner filling.
Processes far the production of co-extruded products are already known. EP 487 757 relates to a process for the production of a co-extruded product with an outer envelope based on cereals.
The disadvantage of this process is that the outer envelope of the product obtained does not have a uniform thickness because the moulding time of the product is boo short to guarantee such a result. This is troublesome above all in cases where it is intended to produce a product of which the filling is liquid, semi-liquid or in the form of a powder.
Composite praduc~s comprising an outer envelope and an inner filling are alto known, for example from EP 178 187, EP 88 574 and EP 487 757. Tn these patents, the products in question comprise outer envelopes based on cereals with moisture contents of 8 to 10% by weight.
With moisture contents of this order, the products in question are not difficult'-to keep at ambient tempera ture.
The problem addressed by the present invention was to provide a process for the produat~on of a co-extruded product with a 'liquid; semi-liquid' or powder-form inner filling which would minimize the risks of obtaining a product whose'~filling might run or be visible from the outside.
The process according to the invention would be useable both in human and in animal nutrition., Another object of the invention was to provide an arrangement for carrying out the process.

The present invention relates to a process for the production of a co-extruded product comprising an outer envelope and a filling, in which the outer envelope is extruded and the filling is delivered to the exit of the extrusion die to form a co-extruded strand which then enters a moulding unit where it is moulded by a pressure roller and the product obtained is cooled. In the extrusion step, the outer envelope is subjected to extrusion cooking.
According to one aspect of the present invention there is provided coextruded product comprising an outer envelope having a uniform thickness and an inner liquid, semi-liquid or powdered filling, wherein the outer envelope based on textured meat or fish has a moisture content comprised between 20 and 40% by weight and additionally contains phosphoric acid, an additive to lower the water activity to a content comprised between 3 and 5% by weight, an anti-mould product and an antioxidant, and the filling represents between 30 and 40 of the total volume and consists of a mixture based on a product chosen from animal fat having a melting point of 35°C, vegetable fat having a melting point of 35°C and powdered yeast.
According to a further aspect of the present invention there is provided process for obtaining a coextruded product as defined above, wherein the outer envelope is extruded at a temperature between 120 and 200°C and the filling is delivered to the outlet from the extrusion die so as to form a coextruded rope which then passes into a forming unit for carrying out moulding at a temperature of the order of 70°C
over a period of the order of a second by a pressure roller and the product obtained is air cooled to a temperature between 20 and 70°C, the forming unit being of the type comprising an outer ring equipped with dies, eccentrically positioned with respect to a crown body also equipped with a die, both the outer ring and the crown body being mounted for rotation and driven by a single motor.

2a In cases where it is intended to obtain a product suitable as an animal food, the mixture for the outer envelope which enters the extruder is a mixture of a suspension of textured meat or fish, a flour of cereals and starches and a solution of phosphoric acid and an additive to reduce the water activity.
In the context of the invention, textured meat or fish is understood to be a meat or fish paste in which the functional properties of the proteins have been partly or completely modified by heat treatment, mechanical treatment and by binders during the extrusion step. Meat is understood to be meat from poultry, rabbits, cattle or sheep, meal obtained from carcasses of the animals mentioned or offal.
By offal is meant both lobes of lung and liver or kidneys.
By fish is meant any type of fish and fish meal. In this case, the filling consists of a mixture based on a product selected form vegetable oil, animal oil and yeast powder.
In cases where it is intended to produce a product suitable for human consumption, it is possible above all to make products of which the outer envelope is based on cereals and the filling consists of semi-liquid chocolate, almond paste or cocoa powder. In this case, the outer envelope is prepared from a mixture of flours, water, sugar, salt, colorants and flavouring.
Pastas filled with meat or spheres of cereals filled ~13~366 with cream mar also be produced by the process according to the invention.
The temperature profile of the extruder is between 120 and 200 ° C,: For animal food products, the temperature profile is between 15o and 160°C. For products intended for human consumption, the temperature profile is between 120 and 240°C. The filling is normally introduced at ambient temperature or at a higher temperature. Accord-ingly, the convention provides an extrusion cooking process by which it is possible to obtain a product ready for use. ., When the co-extruded strand issues from the co-extrusion head, it is cooled to a temperature of the order of 70°C:vand moulded for about 1 second.
25 After moulding, the ca-extruded product is cooled to a temperature of 20 to 70°C.
The extruder is operated at a throughput of 150 to s00 kg/h. Where the end product is intended for human consumption,'~he extruder is operated at a throughput of around 150 kg/h whereas, for animal food products, the throughput mad be higher, for example between 300 and 600 kg/h. The rate of travel of the co-ext~uded'strand is of the order of 10' to 4o mjminute>
The present invention also relates to an arrangement for carrying: out he process described above: Tho arrangement according to the invention comprises an extruder, a co-extrusion head, a moulding unit and a cooling system.
This production line is extremely compact and has a length of the-order of 20 m. A twin-screw extruder, for example of the ype manufactured by Clextral or Werner &
Pfleiderer, is used as the extruder. It has a length of 1.2 to 1.8 m.
The co-extrusion head is round with a diameter of the order of 20 mm and comprises a pass~.ge for feeding w the filling substantially to the centre of the paste.
The moulding unit is of the type used in confec-tionery for the production of sweets, comprising an outer ring equipped with dies and positioned eccentrically in relation to a crown similarly equipped with dies, both the ring and the crown being mounted for rotation and driven simultaneously by a single motor in order con-tinuously to ,form the co-extruded product. The two elements are eccentrically positioned to allow entry of 20 the strands, their moulding as such and their expansion.
The co-extruded product issues at a temperature of the order of 70°C, passes onto a distributing belt and, finally, arrives in a cooling system in which it is cooled with ambient air in one or more stages.
25 It is possible by the process and the arrangement according to the invention to produce a co-extruded product free from any risk of running of the filling at high output rates; with no waste and in a highly compact production Line:
20 The present invention also relates to the co-ex-truded products which is storable at ambient temperature and in which the outer envelope has a water content we~:l above 100.
The invention relates to a co-extruded product in 25 which the outer envelope based on textured fish or meat has a moisture content of 20 to 40% and the filling represents 30 to 40% of the total volume and consists'of a mixture based on a product selected'from vegetable ail, animal oil arid yeast powder.
30 In the context of the invention, a storable product is understood to be bne which can be stored for more than 6 months at ambient'temperature in a sealed pack. Unless otherwise indicated, all the percentages are by weight.
The co-extruded product according to the invention 35 is intended for use as an animal food, for example for ~I3~366 domestic animals, such as cats and dogs, and - because it is obtained by extrusion cooking - it is directly ready for use.
the outer envelope of the product according to the 5 invention additionally contains flour of cereals and/or starches, such as wheat starch or potato starch.
:Since the product according to the invention has a high~noisture content, the outer envelope must contain a preservative, such as phosphoric acid, an additive to reduce the water activity, an anti-mold agent and an anti~cidant. The additive for reducing the water acti-vity>a.is normally a mixture of glycerol and hydrolysed whey-;and is used in a quantity of 3 to 5%. The phos-phor~ acid is also used in a quantity of 3 to 5%, based on the total weight of the outer envelope. The anti-mold agent, is normally sorbate and citrate of potassium used in a:~~quantity of -0:5 0 1% while the antioxidant is normally BHA (butylhydro~yanisole) or BHT (butylhydrpxy-tolu~ne) in a quantity;'of o.1 to 0.20.
:the filling is liquid, semi-liquid or in the form of a powder. To obtain a liquid or semi-liquid filling, fats;:: milk-based products or meat of a type other than that:~sed for the outer envelope are used.
'::.The filling normally consists of an animal or vege't~ble fat with a milting point of 35°C, for ~xampl'e soybean ail or tallow.
:<:To increase the appetency of the co-extruded product according to the invention, the filling addition2~lly contains from 5 to 20% og yeast.
:The filling may also be in the form of a powder., In this~case, the filling is selected from the following constituents, either individually or in combinotion:
sugar, yeast, milk powder, vitamin, mineral elements.
The shape of the co-extruded product is not criti-cal. Preferably, it is substantially round, oval or elliptical. The co-extruded product is either in a single colour or in several colours and is between 15 and 60 mm in size.
In one particular embodiment, the envelope comprises a mixture of 40 to 60% by weight of textured meat or fish, between 30 and 45% of cereal or starch flour, between 3 and 5% of phosphoric acid and the additive for reducing the water activity, the anti-mold agent and the antioxidant in the quantities mentioned above.
The co-extruded product according to the invention has high appetency and may be made in a variety of shapes in relation to the products currently available on the market. Its major advantage is its elasticity.
The invention is described in more detail in the following with reference to the accompanying drawings, wherein:
Figure 1 diagrammatically illustrates the arrange-ment according to the invention.
Figure 2 diagrammatically illustrates the co-ex-trusion head.
Figure 3 is a section through the product in a first embodiment.
Figure 4 is a section through the product in a second embodiment.
The extruder (1) is charged with the required starting material, for example with flour and a meat suspension for an animal food product. Taking into account the temperature profile, for example of the order of 150 to 160°C, the paste (5) arriving at the co-extru-sion head (2) is cooked. The pumping system (3) delivers the filling (6) through the passage (7) to the centre of the paste (5). A co-extruded strand (8) is obtained and, after adequate profiling, is delivered to a moulding unit (4). This moulding unit is of the UNIPLAST type manufac-tured by the Bosch company and comprises a feed system Trade-mark ~~3~3~6 (9) for the strand and an outer ring system (10) equipped with dies which is positioned eccentrically in relation to a crown (11), both elements being simultaneously rotated by a system (12) effecting the transmission between a motor (not shown) and the crown. The moulding unit operates as follows: the strand (8) enters at (13), is preshaped at (14), separated at (15) and then expanded at (16). The co-extruded product (17) are then ejected at (28) and delivered from a feed channel (19) to the distributing belt (20) and then to the air cooling system (21). This system has three stages. The products (17) are transported by a conveyor belt (22) in the direction of the arrow (A), drop onto the conveyor belt (23j in the direction of the arrow (B) and finally drop onto the conveyor belt (24) in the direction of the arrow (C) where they are ready to be packed in a sealed pack.
The arrangement according to the invention may also be used for making products intended for human consump-tion, such as: cereal-based spheres filled with chocolate.
Referring to Fzg: 3, the co-extruded product compri-ses a meat-based outer envelope (30) having a water content of 28:50 with an aW of 0:86. The inner filling (31) is based'on soybean oil and yeast.
In Fig. 4, the outer envelope (32) is based on fish and has a water content of 27.50 with an aw of 0.86: The filling (33) i~ again based on soybean oil and yeast.
The invention is further illustrated by the follow-ing Examples.
Example 1 This Example relates to an embodiment of the process according to the invention for making an animal food product.
50% by weight of meat suspension is mixed in an extruder with 40% of a mixture of flours and 10% of a suspension of preservative.
The meat suspension is obtained by breaking up loaves frozen to -21°C and then grinding, fine-grinding and mixing in a kneader potassium sorbate, flavouring and antioxidants . The meat used is a 50 : 50 mixture of pig lung and meat.
The flours are obtained simply by mixing potato starch, glucose, blood plasma and wheat gluten.
For the suspension of preservative, phosphoric acid, l0 glycerol and hydrolysed whey are mixed in a kneader.
The three components described above are separately introduced into a Clextral BC 72 extruder. The zones of the extruder are at temperatures of 22, 28, 140 and 160°C. The meat and the flour are introduced into the extruder at a rate of 125 kg/h while the preservative suspension is introduced at a rate of 25 kg/h.
A filling consisting of a mixture of soybean oil and yeast is used to increase appetency. The filling is delivered to the co-extrusion head at a rate of 25 kg/h.
The filled strand issues at a rate of Z5 m/minute and is cooled by the circulation of water around the strand (double-jacket cooler). It has a diameter of 20 mm. The strand is then delivered to a UNIPLAST 160 moulding unit which rotates at a variable speed according to the speed at which the co-extruded strand arrives.
The co-extruded products are then cooled in a three-level belt cooler.
An output of 30o kg/hour is obtained.
The appetency tests carried out with these products produced better results compared with the products currently available on the market.
Example Z
This Example relates to an embodiment of the process according to the invention for making products intended * Trade-mark ~~3z~~s for human cax~umption. In this case, the outer envelope comprises 80%-of cereals, 10% of sugar and 10% of water and is subjected to extrusion cooking at 160°C.
The filling consists of 80% of chocolate and 20% of ground almonds. The co-extruded strand issues at a rate of 15 m/minut~.
Example 3 The filling of the co-extruded product contains 77%
of soybean o~.l~, 20% of yeast, an antioxidant, sorbate and citrate of p~ot'assium and lecithin. This filling makes up 35% of the plume of the product.
The outer envelope comprises 40% of a dry mixture of potato starch., glucose, blood plasma and wheat gluten, 50% of a suspension of pig lung and meat and 10% of a suspension 3~ased on phosphoric acid as preservative and glycerol and: hydrolysed whey as an additive for reducing the water ac~.tivity.
Exa~~9le 4 The filling of the co-extruded product is the same as in Example 3.
The outer envelope comprises 400 of a dry mixture of potato starch, glucose, blood plasma and wheat gluten, 50% of a suspension of sardines and 10% of a suspension of phosphoric acid, glycerol and hydrolysed whey.
Ex~np7.e 5 The filling of the co-extruded product is the same as in Example 3.
The outer envelope comprises 40% of a dry mixture of wheat, potata starch, blood plasma, wheat gluten and glucose, 500 of a suspension of pig lung and meat, chicken tissue and autolysate and 10% of a suspension of phosphoric acid, glycerol and hydrolysed whey.

~~~~~ss Exaangle 8 The outer envelope is the same as in Example 5 while the filling consists of 50% of yeast powder and 50% of sugar.

Claims

1. Coextruded product comprising an outer envelope having a uniform thickness and an inner liquid, semi-liquid or powdered filling, wherein the outer envelope based on textured meat or fish has a moisture content comprised between 20 and 40% by weight and additionally contains phosphoric acid, an additive to lower the water activity to a content comprised between 3 and 5 % by weight, an anti-mould product and an antioxidant, and the filling represents between 30 and 40 of the total volume and consists of a mixture based on a product chosen from animal fat having a melting point of 35°C, vegetable fat having a melting point of 35°C and powdered yeast.

2. Coextruded product according to claim 1, wherein the outer envelope additionally contains cereal or starch flour.

3. Coextruded product according to claim 1 or 2, wherein the filling contains soya oil.

4. Coextruded product according to claim 3, wherein the filling contains between 5 and 20% by weight of yeast.

5. Coextruded product according to any one of claims 1 to 4, wherein the filling is a powder, chosen from amongst the following constituents: sugar, yeast, milk powder, vitamins and mineral elements.

6. Coextruded product according to any one of claims 1 to 5, wherein in the outer envelope textured meat or fish represents between 40 and 60% by weight, cereal or starch flour between 30 and 45% by weight, phosphoric acid and the additive for lowering the water activity between 3 and 5% by weight, the anti-mould product between 0.5 and 1% by weight and the antioxidant between 0.1 and 0.2% by weight.

7. Process for obtaining a coextruded product according to any one of claims 1 to 6, wherein the outer envelope is extruded at a temperature between 120 and 200°C and the filling is delivered to the outlet from the extrusion die so as to form a coextruded rope which then passes into a forming unit for carrying out moulding at a temperature of the order of 70°C over a period of the order of a second by a pressure roller and the product obtained is air cooled to a temperature between 20 and 70°C, the forming unit being of the type comprising an outer ring equipped with dies, eccentrically positioned with respect to a crown body also equipped with a die, both the outer ring and the crown body being mounted for rotation and driven by a single motor.

8. Process according to claim 7, wherein the components of the outer envelope are mixed in the extruder.

9. Process according to claim 7 or 8, wherein a throughput of 150 to 600 kg/h is used together with a rate of travel of the coextruded rope of the order of 10-40 m/min.