GB2570933A

GB2570933A - Filling composition for coated food products

Info

Publication number: GB2570933A
Application number: GB1802276.4A
Authority: GB
Inventors: Pillay Adushan; Jan Kelder Reindert; Mtalana Loyiso
Original assignee: Freddy Hirsch Group AG
Current assignee: Freddy Hirsch Group AG
Priority date: 2018-02-12
Filing date: 2018-02-12
Publication date: 2019-08-14
Also published as: AR114367A1; UY38087A; WO2019154883A1; ZA201900853B; GB201802276D0

Abstract

A filling composition for a coated food product comprises animal matter, a protein extender, modified starch, fibre and water. The animal matter may be in an amount from 25 to 60%, the protein extender in an amount from 2 to 7%, the modified starch in an amount from 3.5 to 9.5%, the fibre in an amount from 1 to 4.5%, and the water in an amount from 30 to 60% by weight of the filling composition. The modified starch may be heat-sensitive modified starch and may be derived from potato, maize, tapioca or wheat. Also disclosed is a coated food product comprising a filling composition as described above and a coating material.

Description

FILLING COMPOSITION FOR COATED FOOD PRODUCTS

The present invention relates to filling compositions for use in a coated food product, as well as coated food products comprising the filling composition. The filling compositions are particularly suitable for use in the extrusion filling of coated food products, such as sausages.

Synthetic coatings for food products, such as sausage casings, are well known in the art. Synthetic coatings are typically made from cellulose, though collagen and even plastics may also be used. A disadvantage of these coating materials is that they tend to confer an unnatural and unappealing texture to the outside of a food product and, in some cases, the coating is inedible. This means that synthetic coatings often have to be removed from the food product before consumption, particularly where an imperceptible coating is desirable such as with a skinless sausage. This also adds to the risk of food contamination due to added handling of the food product.

Anionic polymers have been used in synthetic food coatings, such as sausage casings, for some time. Alginate is an edible anionic polymer which is made up of two different uronic acid monomers, namely guluronic acid (G-blocks) and mannuronic acid (M-blocks). Alginate is commonly used to form sausage casings as part of a process in which a solution of alginate is extruded through a circular die around a food product and subsequently treated with calcium chloride (see e.g. WO 2016/027261). During this process, the alginate solution undergoes a gelification process in which matrices of cross-linked alginate chains form. The M-blocks form linear molecular chains (M-M-M-M-M), whilst the G-blocks form folded structures (G-G-G-G). Alternating regions consisting of M- and G-chains form the fundamental alginate structure, which can vary with seaweed type and seasonal climate.

Synthetic coatings are typically added to a filling composition for a coated food product by extrusion. Thus, both a coating material and a filling composition must exhibit suitable properties for successful extrusion. For instance, in the case of coating material, it is essential that the viscosity can be controlled, since too high or two low viscosity can impede extrusion of the coating material onto the filling composition. In the case of the filling composition, it is essential that the mixture is not too mushy or too firm, as this can also reduce the efficiency of the extrusion process, and in some instances render extrusion impossible. Similarly, the consistency of the filling composition must be adequate for the subsequent processing to which an extruded product is typically subjected, e.g.

strengthening of the casing material by immersion in a strengthening solution and/or cooking of the product in a water bath.

Filling compositions for food products such as sausages will often comprise water in an amount of greater than 20 %, and animal matter in an amount of less than 60 % by weight of filling composition, particularly where the sausages are for production on a large economic scale. Given the relatively high moisture content of these products, these filling compositions can be quite soft. However, some consumers prefer a sausage with a firmer texture.

It is also important that a filling composition and a synthetic coating material are compatible with one another, in particular that good adhesion is observed between the filling composition and the coating material on extrusion of a coated food product. If good adhesion is not achieved then bubbles can form under the coating material during cooking, as a result of the moisture that is driven from the filling composition. This is particularly the case when the coated food product is cooked at high temperature e.g. by frying in oil. Bubble formation can be visually unappealing to consumers, as well as enhancing perception of the casing material during eating. In severe cases, the coating material can split, thereby damaging the structural integrity and appearance of the product.

Accordingly, there is a need for a filling composition which is suitable for use with a synthetic coating material in an extrusion process, but which also exhibits a desirable texture for the consumer on eating.

The present invention is based on the unexpected discovery that, by adding a combination of modified starch, protein extender and fibre to a filling composition for a coated food product having a high moisture content, a filling composition may be prepared which is readily extrudable with a synthetic casing material and which also exhibits desirable properties on eating.

Thus, in a first aspect, the present invention provides filling composition for a coated food product, said filling composition comprising, by weight of the filling composition:

animal matter;

protein extender;

modified starch;

fibre; and water.

A method for preparing the filling composition of the present invention is also provided. The method comprises combining:

animal matter;

protein extender;

modified starch;

fibre; and water.

In a further aspect, the present invention provides a coated food product which comprises: a filling composition of the present invention; and a synthetic coating material.

A method for preparing a coated food product is also provided. The method comprises: applying a coating material to a filling composition of the present invention. A coated food product obtainable by said method is also provided.

In a further aspect, the present invention provides a kit comprising: protein extender, modified starch and fibre; and instructions for preparing a filling composition or coated food product of the present invention.

Also provided is the use of a filling composition of the present invention in a coated food product; and the use of a combination of protein extender, modified starch and fibre for improving the extrusion and/or cooking and/or texture properties of a filling composition which comprises water and animal matter.

In a further aspect, an apparatus is provided for preparing a coated food product. The apparatus comprises a tank in which a filling composition of the present invention is held; and a coating device for coating the filling composition with a coating material.

The present invention is based on the discovery that many of the problems previously encountered with preparing coated food products having a filling composition with a high moisture content may be overcome by adding a combination of modified starch, protein extender and fibre to the filling composition. Such coating materials display excellent extrusion, processing and eating properties. In particular, the compositions may be successfully extruded and processed, whilst still providing a pleasing texture to the consumer on eating.

The modified starch is preferably a heat-sensitive modified starch. Heat-sensitive modified starches are starches in which particular properties are only activated at a certain temperature. In the present case, the heat-sensitive starches are preferably activated to become firmer at certain temperatures. This has the advantage that the filling composition remains soft during extrusion, but firms up on cooking. Preferably, the heat-sensitive modified starches that are used in the present invention are activated at a temperature of greater than 50 °C, preferably greater than 60 °C, and more preferably greater than 70 °C. The heat-sensitive modified starches may be activated at a temperature of lower than 120 °C, preferably lower than 110 °C, and more preferably lower than 100 °C. Thus, the heatsensitive modified starches may be activated at a temperature in the range of from 50 to 120 °C, preferably from 60 to 110 °C, and more preferably from 70 to 100 °C.

The modified starch may be derived from potato, maize, tapioca or wheat. Modified starches derived from potato, maize (e.g. waxy maize) or tapioca are particularly suitable for use in the filling compositions of the present invention.

The modified starch may be starch in which -OH groups have been modified, e.g. esterified or etherified. It will be appreciated that modified starches typically have some, and not all, of the -OH groups modified.

-OH groups in the starch may have been esterified to give a group having the formula: OC(O)Ri, where R> is selected from Ci.₆ alkyl groups. Preferably, FT is a methyl group. Esterification may be carried out using acetic anhydride or vinyl acetate.

-OH groups in the starch may have been etherified to give a group having the formula: -OR₂, where R₂ is a C^e alkyl group or a C^e hydroxyalkyl group. Preferably, R₂ is a hydroxy propyl group. Etherification may be carried out using propylene oxide.

Preferably, the modified starch is starch which has been crosslinked, e.g. using a phosphate compound (e.g. sodium trimetaphosphate or phosphorus oxychloride) or an anhydride (e.g. adipic anhydride).

It will be appreciated that the modified starches used in the filling compositions of the present invention may be modified at their -OH groups and cross-linked.

Preferred modified food starches for use in the present invention include:

• acetylated distarch adipate (EU food additive E1422, a cross-linked starch having esterified -OH groups; e.g. derived from waxy maize such as that sold under the tradename Purity™ HPC);

• acetylated starch (EU food additive E1420, a starch having esterified -OH groups; e.g. derived from tapioca starch such as that sold under the tradename Elastitex™) • hydroxypropyl distarch phosphate (EU food additive E1442, a cross-linked starch having etherified-OH groups; e.g. derived from waxy maize such as that sold under the tradename Firm-tex™); and • Almidon National™ 1317, a cross-linked starch.

Modified starches may be used in the filling composition in an amount of at least 3.5 % by weight, preferably at least 4 % by weight, and more preferably at least 4.5 % by weight of the filling composition. Modified starches may be used in a total amount of up to 9.5 % by weight, preferably up to 8.5 % by weight, and more preferably up to 7.5 % by weight of the filling composition. Thus, the filling composition may comprise modified starches in a total amount of from 3.5 to 9.5 % by weight, preferably from 4 to 8.5 % by weight, and more preferably from 4.5 to 7.5 % by weight of the filling composition.

The filling composition may optionally comprise unmodified starch. The unmodified starch may be derived from potato, maize, tapioca or wheat. Preferably, the unmodified starch is derived from potato. An example of a preferred unmodified starch for use in the filling composition of the present invention is a potato-derived starch sold under the tradename NHance®.

Unmodified starches may be used in the filling composition in an amount of at least 0.75 % by weight, and preferably at least 1.25 % by weight of the filling composition. Unmodified starches may be used in a total amount of up to 4 % by weight, preferably up to 3.5 % by weight, and more preferably up to 3 % by weight of the filling composition. Thus, the filling composition may comprise unmodified starches in a total amount of from 0 to 4 % by weight, preferably from 0.75 to 3.5 % by weight, and more preferably from 1.25 to 3 % by weight of the filling composition.

The ratio of modified starch to unmodified starch in the filling composition may be greater than 1:1, preferably greater than 1.25 : 1, and more preferably greater than 1.5 : 1. The ratio of modified starch to unmodified starch in the filling composition may be up to 10 : 1, preferably up to 8 : 1, and more preferably up to 5 : 1. Thus, the ratio of modified starch to unmodified starch in the filling composition may be from 1 : 1 to 10 : 1, preferably from 1.25 : 1 to 8 : 1, and more preferably from 1.5 : 1 to 5 : 1.

Protein extenders are also used in the filling composition of the present invention. Protein extenders enhance the protein content of the filling composition. Without wishing to be bound by theory, it is believed that the use of protein extenders, at least in part, improves the textural eating properties of the filling composition for the consumer, as well as enhancing the extrusion properties of the filling composition.

The protein extender used in the filling composition may be derived from soya beans. For instance, the protein extender may be a soya isolate or a soya concentrate. As is known in the art, soya concentrate is prepared by removing the fat and water-soluble non-protein components from soya beans. Thus, soya concentrate may contain some carbohydrates and fibre. Soya isolates are prepared by removing all non-protein components from soya beans, and this are substantially carbohydrate and fibre free.

Protein extenders may be used in the filling composition in an amount of at least 2 % by weight, preferably at least 2.5 % by weight, and more preferably at least 3 % by weight of the filling composition. Protein extenders may be used in the filling composition in a total amount of up to 7 % by weight, preferably up to 6 % by weight, and more preferably up to 5 % by weight of the filling composition. Thus, the filling composition may comprise protein extenders in a total amount of from 2 to 7 % by weight, preferably from 2.5 to 6 % by weight, and more preferably from 3 to 5 % by weight of the filling composition. It will be appreciated that these amounts relate to the protein extender that is added to the filling composition during its preparation, and do not include proteins that are added to the filling composition as part of the animal matter.

Fibre is also used in the filling composition of the present invention. It is believed that the fibre, at least in part, improves the structure of the filling composition ‘emulsion’ so that it may be readily extruded. Surprisingly, this effect may be achieved without compromising the eating properties perceived on consumption of the filling composition.

The fibre may be derived from wheat or soya beans. Particularly preferred is fibre derived from soya beans.

Fibre may be used in the filling composition in an amount of at least 1 % by weight, preferably at least 1.5 % by weight, and more preferably at least than 2 % by weight of the filling composition. Fibre may be used in the filling composition in a total amount of up to 4.5 % by weight, preferably up to 4 % by weight, and more preferably up to 3.5 % by weight of the filling composition. Thus, the filling composition may comprise fibre in a total amount of from 1 to 4.5 % by weight, preferably from 1.5 to 4 % by weight, and more preferably from 2 to 3.5 % by weight of the filling composition. It will be appreciated that these amounts relate to the fibre that is added to the filling composition during its preparation, and do not include fibre that has been added to the filling composition as part of the animal matter.

The ratio, by weight, of protein extender to fibre may be greater than 0.8 : 1, preferably greater than 1 : 1, and more preferably greater than 1.2 : 1.

The filling composition comprises animal matter. The animal matter may comprise red meat (e.g. beef, lamb, goat or bison), pork, poultry (e.g. chicken or turkey), fish or combinations thereof. In preferred embodiments, the animal matter is shredded, minced, pureed or in the form of a paste in the filling composition.

Animal matter may be used in the filling composition in an amount of at least 20 % by weight, preferably at least 25 % by weight, and more preferably at least 30 % by weight of the filling composition. Animal matter may be used in a total amount of up to 60 % by weight, preferably up to 50 % by weight, and more preferably up to 45 % by weight of the filling composition. Thus, the filling composition may comprise animal matter in a total amount of from 20 to 60 % by weight, preferably from 25 to 50 % by weight, and more preferably from 30 to 45 % by weight of the filling composition.

Water may be used in the filling composition in an amount of at least 30 % by weight, preferably at least 35 % by weight, and more preferably at least 40 % by weight, by weight of the filling composition. Water may be used in an amount of up to 60 % by weight, preferably up to 55 % by weight, and more preferably up to 50 % by weight of the filling composition. Thus, the filling composition may comprise water in an amount of from 30 to 60 % by weight, preferably from 35 to 55 % by weight, and more preferably from 40 to 50 % by weight of the filling composition. It will be appreciated that these amounts relate to the water that is added to the filling composition during its preparation, and do not include water that has been added to the filling composition as part of the animal matter.

Particularly preferred filling compositions comprise animal matter, water, protein extender, starch (modified and, if used, unmodified) and fibre in a combined total amount of at least 90 % by weight, preferably et leest 94 % by weight, end more preferably et leest 96 % by weight of the filling composition.

The filling composition will generally comprise further ingredients, such as flavourings (synthetic or natural, e.g. herbs), seasonings, breadcrumbs, oats, vegetable matter, additives etc.

In some embodiments, the filling composition may comprise a calcium compound or a phosphate compound, and preferably both. The use of these components is believed to improve binding of the coating material to the filling composition.

Suitable calcium compounds include CaCI₂, calcium lactate or calcium acetate, with calcium lactate particularly preferred. Calcium compounds may be used in the filling composition in an amount of at least 0.1 % by weight, preferably at least 0.15 % by weight, and more preferably at least 0.2 % by weight of the filling composition. Calcium compounds may be used in a total amount of up to 0.5 % by weight, preferably up to 0.4 % by weight, and more preferably up to 0.3 % by weight of the filling composition. Thus, the filling composition may comprise calcium compounds in a total amount of from 0.1 to 0.5 % by weight, preferably from 0.15 to 0.4 % by weight, and more preferably from 0.2 to 0.3 % by weight of the filling composition.

Suitable phosphate compounds include sodium tripolyphosphate (STPP). Phosphate compounds may be used in the filling composition in an amount of at least 0.01 % by weight, preferably at least 0.05 % by weight, and more preferably at least 0.1 % by weight of the filling composition. Phosphate compounds may be used in a total amount of up to 0.35 % by weight, preferably up to 0.30 % by weight, and more preferably up to 0.25 % by weight of the filling composition. Thus, the filling composition may comprise phosphate compounds in a total amount of from 0.01 to 0.35 % by weight, preferably from 0.05 to 0.30 % by weight, and more preferably from 0.1 to 0.25 % by weight of the filling composition.

The ratio of calcium compounds to phosphate compounds in the filling composition is preferably greater than 1:1, and more preferably greater than 1.5 : 1 by weight.

The filling composition of the present invention may be prepared by a method in which the animal matter, water, protein extender, modified starch and fibre are combined.

In some embodiments, the method for preparing the filling composition comprises the step of combining the dry components (e.g. protein extender, modified starch and fibre), and combining the liquid components (e.g. animal matter and water), and subsequently combining the dry components with the liquid components. The dry components may be premixed before they are combined with the liquid components and/or the liquid components may be premixed before they are combined with the dry components.

The method of preparing the filling composition may comprise the step of mixing the components of the filling composition. Methods of mixing are known in the art. Mechanical mixing methods are preferably used. Suitable devices for carrying out mechanical mixing are readily available.

The filling composition will generally be prepared at a temperature of from 0 to 30 °C, preferably from 2 to 20 °C, and more preferably from 4 to 15 °C.

The filling composition is preferably prepared in batches.

Once the filling composition has been prepared, it may be used as the filling in a coated food product.

The coated food product is preferably a coated moulded food product, in which the ingredients have been processed (e.g. by chopping, shredding or grinding the ingredients). Coated moulded food products include burgers, kebabs and sausages. In preferred embodiments, the coated food product is a sausage, such as a meat sausage. Skinless meat sausages are particularly preferred. Skinless meat sausages are intended to mimic the sensory attributes of traditionally prepared hotdog sausages.

The coated food product may be a raw, partially cooked or cooked food product.

In the coated food products of the present invention, the filling composition is, at least partially, covered by a coating material. Thus, the coating material may cover at least 50 %, preferably at least 70 %, and more preferably at least 90 % of the surface area of the coated food product. Most preferably, all of the surface area of the coated food product is covered with the coating material.

The coating material may have a thickness of at least 50 pm, preferably at least 100 pm, and more preferably at least 150 pm. The coating material may have a thickness of up to

300 pm, preferably up to 250 pm, and more preferably up to 200 pm. Thus, the coating material may have a thickness of from 50 to 300 pm, preferably from 100 to 250 pm, and more preferably from 150 to 200 pm.

The coating material may have a tensile strength such that the load required to rupture an extruded coating of 100 pm thickness is at least 100 g, preferably at least 150 g, and more preferably at least 200 g. The extruded coating may have a tensile strength such that the load required to rupture an extruded coating of 100 pm thickness is up to 400 g, preferably up to 350 g, and more preferably up to 300 g. Thus, the extruded coating may have a tensile strength such that the load required to rupture an extruded coating of 100 pm thickness is from 100 to 400 g, preferably from 150 to 350 g, and more preferably from 200 to 300 g.

Tensile strength is measured using a Brookfield CT3 texture analyser which is operated with a TA18 sphere (12.7 mm in diameter) and a fixture TA-RT-KIT. The system settings are: test type set as rupture, a test target correction of 50 g, a trigger load of 5 g and a test speed of 1 mm/s.

The coating material is preferably applied to the filling composition in the form of an aqueous coating material.

The coating material preferably comprises a polysaccharide. The polysaccharide may be a neutral polysaccharide, such as cellulose, or an anionic polysaccharide. Anionic polysaccharides are particularly preferred for use in the coating material.

Anionic polysaccharides are understood to contain functional groups which exist in an anionic form at a pH of 7. In preferred embodiments, the anionic polysaccharide used in the aqueous coating material comprises uronic acid monomers. Preferably, the anionic polysaccharide comprises uronic acid monomers selected from guluronic acid and mannuronic acid. More preferably, the anionic polysaccharide is alginate, i.e. a polymer comprising guluronic acid and mannuronic acid monomers.

The alginate is preferably a high-guluronic acid alginate. For instance, the ratio of guluronic acid monomers to mannuronic acid monomers in the alginate may be greater than 1:1, preferably greater than 1.5:1, and more preferably greater than 2:1. The alginate preferably comprises homopolymeric blocks of guluronic acid monomers.

The anionic polysaccharide may also be a pectin (e.g. a low methoxyl pectin) or, more preferably, a combination of an alginate and a pectin.

Anionic polysaccharides may be included in the aqueous coating material in an amount of at least 2 %, preferably at least 2.5 %, and more preferably at least 2.8 % by weight of the coating material. Anionic polysaccharides may be included in a total amount of up to 8 %, preferably up to 6 %, and more preferably up to 4.5 % by weight of the coating material. Thus, the coating material may comprise anionic polysaccharides in a total amount of from 2 to 8 %, preferably from 2.5 to 6 %, and more preferably from 2.8 to 4.5 % by weight of the coating material. These levels of anionic polysaccharide are believed to provide a food product coating that is not overly discernible to the consumer. Where a food product is desired with a ‘skinless’ feel, e.g. a skinless sausage, then anionic polysaccharides are preferably used in a total amount of less than 3.5 % by weight of the coating material.

Preferred coating materials for use with the filling composition of the present invention also contain a plasticiser and an interrupting agent.

Plasticisers are components which soften a coating material. The plasticiser used in the aqueous coating material of the present invention is preferably a polyol, such as a C^w polyol, preferably a C₂.s polyol, and more preferably a C₃.₆ polyol. Suitable polyols include glycerol (propane-1,2,3-triol), propylene glycol (also known as propane-1,2-diol) or sorbitol ((2S,3R,4R,5R)-hexane-1,2,3,4,5,6-hexol). Glycerol is particularly suitable for use in the casing materials of the present invention.

Plasticisers may be included in the aqueous coating material in an amount of at least 8 % by weight, preferably at least 12 % by weight, and more preferably at least 18 % by weight of the coating material. Plasticisers may be included in a total amount of up to 42 %, preferably up to 38 %, and more preferably up to 32 % by weight of the coating material. Thus, the coating material may comprise plasticisers in a total amount of from 8 to 42 %, preferably from 12 to 38 %, and more preferably from 18 to 32 % by weight of the coating material.

Interrupting agents disrupt the spatial orientation of the anionic polysaccharide chains in the coating material. Suitable interrupting agents for use in the coating materials include microcrystalline polysaccharides, such as microcrystalline cellulose, and starches, such as tapioca starch, potato-derived starches and corn starch. Microcrystalline cellulose and tapioca starch are preferably used, with microcrystalline cellulose particularly effective.

Interrupting agents may be included in the aqueous coating material in an amount of at least 0.5 %, preferably at least 1 %, and more preferably at least 1.5 % by weight of the coating material. Interrupting agents may be included in a total amount of up to 8 % by weight, preferably up to 7 % by weight, and more preferably up to 6 % by weight of the coating material. Thus, the coating material may comprise interrupting agent in a total amount of from 0.5 to 8 %, preferably from 1 to 7 %, and more preferably from 1.5 to 6 % by weight of the coating material. Microcrystalline polysaccharides will preferably be used at a lower level than starches, e.g. in a totally amount of up to 2.5 % by weight, with starches preferably used in an amount of at least 4 % by weight of the coating material.

The pH of the aqueous coating material used in the present invention is in the range of from

3.4 to 4.0. For instance, the pH may be in the range of from 3.5 to 3.9, and preferably in the range of from 3.6 to 3.8. In these pH ranges, the anionic polysaccharides exist in the coating material in a partially precipitated state, thereby providing desirable levels of viscosity for extrusion of the coating compositions.

The pH level may be measured using standard methods, for instance by introducing a pH probe which is attached to a pH meter into the aqueous coating material. As is conventional in the art, pH measurements will be taken at 25 °C.

The target pH level may be achieved by using an acid to lower the pH. Suitable acids include organic acids, in particular food grade acids such as citric acid, lactic acid, acetic acid, ascorbic acid and glucono-0-lactone. Citric acid is particularly suitable for controlling the pH level of the aqueous coating material. The acid will be used in an amount suitable to achieve the target pH level.

In order to assist with maintenance of the desired pH level, the coating material may comprise an acidic buffer. The acidic buffer will generally consist of an acid and a metal salt of the same acid, such as a group 1 or group 2 metal salt. Preferably, the buffer is selected from citric acid and sodium citrate; lactic acid and sodium lactate; acetic acid and sodium acetate; and ascorbic acid and sodium ascorbate.

The acidic buffer may be used in the aqueous coating material an amount of at least 0.1 % by weight, preferably at least 0.5 % by weight, and more preferably at least 1 % by weight of the coating material. The acidic buffer may be used in a total amount of up to 10 % by weight, preferably up to 5 % by weight, and more preferably up to 3 % by weight of the coating material. Thus, the acidic buffer may be used in a total amount of 0.1 to 10 % by weight, preferably from 0.5 to 5 % by weight, and more preferably from 1 to 3 % by weight of the coating material.

Since a range of different properties are desirable in a coated food product, then one or more further ingredients may be included in the coating material to help achieve these properties. Examples of one or more further ingredients include smoke derivatives, hydrocolloids and insoluble fibres. Hydrocolloids are particularly suitable for use in the casing compositions of the present invention.

Suitable smoke derivatives include liquid smoke. The use of smoke derivatives in the coating material is desirable because of the flavour that they impart on to the coating. Smoke derivatives may also catalyse hydrolysis of the alginate chains so that texture of the casing is shortened. Smoke derivatives may also be used to increase the viscosity of the coating material.

Smoke derivatives may be included in the aqueous coating material in an amount of at least 1 % by weight, preferably at least 2 % by weight, and more preferably at least 3 % by weight of the coating material. Smoke derivatives may be included in an amount of up to 10 % by weight, preferably up to 8 % by weight, and more preferably up to 5 % by weight of the coating material. Thus, the coating material may comprise smoke derivatives in an amount of from 1 to 10 % by weight, preferably from 2 to 8 % by weight, and more preferably from 3 to 5 % by weight of the coating material.

However, in many embodiments, the level of smoke derivatives is preferably limited since they may lead to an undesirable increase in viscosity in the coating material. Thus, the amount of smoke derivatives included in the aqueous coating material may be limited to less than 3.5 % by weight, preferably less than 1 % by weight, and more preferably less than 0.5 % by weight. In some embodiments, smoke derivatives may even be absent from the coating material.

Suitable hydrocolloids include hydrocolloidal vegetable gums, and preferably guar gum. Other suitable hydrocolloidal vegetable gums include tara gum and locust bean gum. Hydrocolloids may be useful for increasing the viscosity of the coating material.

Hydrocolloids may be included in the aqueous coating material in an amount of at least 0.1 % by weight, preferably at least 0.25 % by weight, and more preferably at least 0.4 % by weight of the coating material. Hydrocolloids may be included in an amount of up to 1 % by weight, preferably up to 0.75 % by weight, and more preferably up to 0.6 % by weight of the coating material. Thus, the coating material may comprise hydrocolloids in an amount of from 0.1 to 1 % by weight, preferably from 0.25 to 0.75 % by weight, and more preferably from 0.4 to 0.6 % by weight of the coating material.

Suitable insoluble fibres include cellulose fibres other than microcrystalline cellulose, citrus fibres and collagen. Insoluble fibres in the coating material may be useful for increasing the viscosity of the coating material.

Insoluble fibres may be included in the aqueous coating material in an amount of at least 0.5 % by weight, and preferably at least 1 % by weight of the coating material though, in preferred embodiments, insoluble fibres will not be used as preferred viscosity levels are already achieved in the coating material. Insoluble fibres may be included in an amount of up to 10 % by weight, preferably up to 5 % by weight, and more preferably up to 3 % by weight of the coating material. Thus, the coating material may comprise insoluble fibres in an amount of from 0 to 10 % by weight, preferably from 0.5 to 5 % by weight, and more preferably from 1 to 3 % by weight of the coating material.

Other ingredients that may be present in the coating material include chelating agents. Suitable chelating agents include phosphates such as sodium hexametaphosphate. Colourings and flavourings, e.g. spices, may also be included in the coating material.

The coating material is applied to the filling composition in the form of an aqueous composition. Water may be used in the aqueous coating material in an amount of at least 50 %, preferably at least 60 %, and more preferably at least 70 % by weight of the coating material.

The aqueous coating material may have a viscosity of at least 20 Pa s, preferably at least 25 Pa s, and more preferably at least 30 Pa s at 5 °C. The coating material may have a viscosity of up to 80 Pa s, such as up to 70 Pa s and preferably up to 60 Pa s at 5 °C. Thus, the aqueous coating material may have a viscosity of from 20 to 80 Pa s, such as 25 to 70 Pa s, preferably from 30 to 60 Pa s at 5 °C. These viscosities are preferred for extrusion of the coating material.

Viscosity is measured in Pa s using a Brookfield R/S-CPS+ Rheometer (cone and plate) which is operated with an external temperature control system at 5 °C, with a C25-1 spindle utilizing a sample volume of 0.08 ml. The system settings are: CSR setting, with a shear time of 120 s but a measuring point at 60 s under linear point distribution with the shear rate parameter selected, with a start and end value set at 20 s'¹, and a distribution measuring points number of 60. The measuring temperature is set to 4 °C.

The aqueous coating material used in the present invention may be prepared by a method in which the anionic polysaccharide (preferably in an anhydrous form), plasticiser and interrupting agent are combined in the presence of water, and the pH of the coating material is adjusted so that it is in the range of from 3.4 to 4.0.

In some embodiments, the water is combined with components of the composition that are in liquid form (e.g. plasticisers) and subsequently combined with the dry components of the composition (e.g. powdered anionic polysaccharide and interrupting agent). Preferably, the method for preparing the coating material comprises the step of pre-mixing the dry components (e.g. anionic polysaccharide and interrupting agent) and pre-mixing the liquid components (e.g. water and plasticiser), and subsequently combining the dry and liquid components.

The step of forming the coating material may comprise the step of mixing the water, anionic surfactant, plasticiser, interrupting agent and any additional ingredients. Methods of mixing are known in the art. High shear mixing is preferably used. Suitable devices for carrying out high shear mixing are readily available.

Once the components of the coating material have been mixed, the viscosity of the coating material may increase over time. Thus, the coating material may be prepared over a period of greater than 10 minutes, preferably greater than 30 minutes, and more preferably greater than 1 hour. Whilst an increase in viscosity may be observed in these periods, it is generally preferable for the viscosity of the coating material to reach a steady state. Thus, in preferred embodiments, the coating material may be prepared over a period of greater than 3 hours, and preferably greater than 6 hours, such as 8 or 10 hours, and such as for a period of greater than 12 hours.

The coating material will generally be prepared at a temperature of from 10 to 40 °C, preferably from 15 to 30 °C, and more preferably from 20 to 25 °C.

The coating material is preferably prepared in batches.

Once the coating material has been prepared, it is preferably homogenised before it is used e.g. in an extrusion process. This is because, during the preparation of the coating material, pockets of insoluble anionic polysaccharide (in which many of the anionic moieties on the polysaccharide chain have been protonated) and soluble anionic polysaccharide (in which few of the anionic moieties on the polysaccharide chains have been protonated) may form. Homogenisation distributes protonated anionic polysaccharide in the form of insoluble particles throughout the coating material. The viscosity of the coating material may reduce as a result of homogenisation.

Homogenisation may be carried out by mixing the coating material, e.g. using a mechanical mixer, a bowl cutter, vacuum blending, or ultrasonification. Slow blending, e.g. for a period of at least 8 hours, may also be used. Other mixing methods will be known to the person of skill in the art and may also be used. Where vacuum blending it used, the homogenisation process may be carried out for a period of at least 10 minutes, preferably at least 20 minutes, and more preferably at least 30 minutes. Vacuum blending may be carried out at a temperature of from 1 to 8 °C, preferably from 2 to 6 °C, for instance at about 4 °C. In order to remove air, the vacuum setting is preferably set high, e.g. at its maximum.

The coated food product of the present invention may be obtained by a method in which the coating material is applied to the filling composition of the present invention.

The coating material may be applied to the filling composition in an amount of at least 0.5 % by weight, preferably at least 1 % by weight, and more preferably at least 2.5 % by weight of the filling composition. The coating material may be applied to the filling composition in an amount of up to 20 % by weight, preferably up to 10 % by weight, and more preferably up to 5 % by weight of the filling composition. Thus, the coating material may be applied to the filling composition in an amount of from 0.5 to 20 % by weight, preferably from 1 to 10 % by weight, and more preferably from 2.5 to 5 % by weight of the filling composition.

The coating material may be applied to the filling composition using methods that are known to the skilled person. In preferred embodiments, the coating material is extruded and applied to the filling composition.

The filling composition is preferably co-extruded with the coating material, though it will be appreciated that the coating material may be first extruded and subsequently applied to a filling composition. In some embodiments, the coating material may be extruded through a circular die which encircles the co-extruded filling composition. This is particularly preferred when the food product is a sausage, since the coating material may be extruded on to the outside surface of the sausage filling.

Extrusion may take place at a linear speed of at least 0.05 m/s, preferably at least 0.1 m/s, and more preferably at least 0.5 m/s. Extrusion may take place at a linear speed of up to 5 m/s, preferably up to 4.5 m/s, and more preferably up to 3.8 m/s. This, extrusion may take place at a linear speed of from 0.05 to 5 m/s, preferably from 0.1 to 4.5 m/s, and more preferably from 0.5 to 3.6 m/s. An advantage of the present invention is that the coating material may be extruded at relatively high speeds without compromising the integrity of the coating. Thus, in some embodiments, the coating material is extruded at a linear speed of greater than 1 m/s.

Once the filling composition has been coated, the coating material may be strengthened by contacting the coated food product with group 2 metal ions. Without wishing to be bound by theory, it is believed that group 2 metal ions may act as ionic cross-linkers between the chains of the anionic polysaccharide. The group 2 metal ions are believed to interact with negatively charged groups that are present in the anionic polysaccharide. Group 2 metal ions are particularly effective at strengthening forms of alginate which comprises homopolymeric blocks of guluronic acid monomers.

The coating material may be strengthened by contacting the coated food product with a solution containing group 2 metal ions, for instance by immersing the coated food product in the solution or by spraying the solution onto the coated food product.

The group 2 metal ions are preferably selected from calcium ions, barium ions and magnesium ions. Calcium ions are generally preferred due their common use in food products. Suitable solutions for strengthening the casing include calcium chloride solutions. Suitable solutions may comprise group 2 metal salts in an amount of at least 5 % by weight, and preferably at least 10 % by weight of the solution.

In some embodiments, the method for preparing a coated food product comprises cooking the coated food product, preferably after it has been strengthened using group 2 metal ions. For instance, the coated food product may be steamed, boiled, fried, or smoked. Preferably, the food product is cooked at a temperature of greater than 50 °C, and more preferably greater than 60 °C. The food product may be partially cooked, or fully cooked.

The coated food product, optionally once cooked, may be further processed by at least one of drying, chilling (e.g. at a temperature of between 1 and 10 °C), and freezing (e.g. at a temperature of less than -5 °C).

Once the coated food product has been prepared, it may be packaged. In some embodiments, the coated food product will be packaged as a single article. Generally, however, at least two, preferably at least four, and more preferably at least six coated food products will be included in a package.

Thus, a coated food product of the present invention may be in a dried, chilled, frozen and/or packaged form.

The present invention provides kits which may conveniently be used for preparing the filling composition and the coated food products disclosed herein.

In an embodiment, the kit may comprise: protein extender, modified starch and fibre; and instructions for preparing a filling composition or coated food product of the present invention.

In embodiments, the kit further comprises a polysaccharide, and preferably a plasticiser and an interrupting agent; and instructions for preparing a coating material.

The kit may comprise one or more further ingredients of the filling composition or coating material as described herein.

In preferred embodiments, the components of the kit are provided in anhydrous form.

As mentioned above, the present invention is based in part on the discovery a combination of protein extender, modified starch and fibre may be used for improving the extrusion and/or cooking and/or texture properties of a filling composition comprising water, e.g. in an amount of at least 30 % by weight of the filling composition, and animal matter.

An improvement in extrusion properties is observed if the filling composition can be extruded at a higher rate, without compromising form. An improvement in cooking properties may be observed as a reduction in the deformation during cooking. Good texture properties are observed on eating where the filling composition exhibits firm, but not hard, texture.

The present invention also provides the use of a filling composition of the present invention in a coated food product.

The coated food product of the present invention may be prepared using an apparatus which comprises: a tank in which the filling composition of the present invention is held; and a coating device in which the filling composition is coated with a coating material, such as a coating material described herein.

The tank may have a volume of greater than 1 L, preferably greater than 5 L, and more preferably greater than 10 L. A tank of this size enables batch-wise production of the filling composition.

In preferred embodiments, the filling composition of the present invention may be prepared in the tank. A water inlet may also be present on the tank to provide water for the filling composition.

The apparatus may further comprise a mechanical mixer. The mechanical mixer may be used to mix the components of the filling composition. The mechanical mixer may be introduced into the tank to mix the filling composition. Alternatively, the tank may be coupled to a mechanical mixer and the filling composition passed from the tank to the mechanical mixer.

The apparatus further comprises a coating device, such as an extruder. The coating device is used to coat the filling composition with the coating material preferably using a method disclosed herein.

The apparatus may further comprise a strengthening station, in which the coating of the coated food product is strengthened by contacting the coated food product with group 2 metal ions preferably as described herein.

The present invention will now be illustrated by way of the following examples.

Examples

Example 1: Screening of filling compositions

An existing high moisture filling composition was used in a high-throughput extrusion process. The extrusion profile was poor, because the filling composition was too soft. Further deformation of the sausages was observed during cooking in a water bath. This was also believed to be due to the softness of the filling composition. The texture of the product on eating was also deemed too soft.

filling compositions were prepared on a small scale. The filling compositions were based on the commercially available filling but contained varying quantities and types of protein extender, additives, starch, fiber and spice pack as shown in Figure 1.

The filling compositions were tested for their ability to be co-extruded with a cellulose casing.

The filling compositions were also tested for their hardness (maximum force required to compress a food between the molars, indicating the brittleness of the food), cohesiveness (an indication of the strength of internal bonds making up the body of the food), springiness index (the recovery properties of a food with 1 representing a completely elastic material and 0 representing a completely viscous material) and chewiness (an indication of the energy required to chew a solid food to a state where it is swallowable). Each filling composition was tested 5 times and an average taken. The measurements were obtained on a CT3™ texture analyzer (BROOKFIELD AMETEK) using the following settings:

Probe	TA4/1000 perspex cylinder (38.1 mm D, 20 mm L)
Sample dimensions T est type T est target Target value Hold time	Cylinder, 15 mm D, 125 mm L Compression Distance 7.5 mm 0 sec
Trigger load Test speed Cycle count	4.5 g 1.0 mm/sec 2

The filling compositions were also assessed fortheir eating quality.

The results of the experiments are shown in Figure 1.

Compositions C1 to C3 formed a poor filling emulsion compared to the Original, and so were not put forward for extrusion. Composition EF1 was not extrudable, and composition EF2 was barely extrudable though the structure did improve on cooking. Compositions EF3 to

EF6 successfully extruded, but EF3 lacked elasticity, EF4 was too pasty I grainy, and EF5 and EF6 were too doughy on eating. Compositions EF7 to EF12 both extruded well and had good eating properties. In particular, EF7 extruded well but lacked a little chewiness, while EF8 exhibited slightly improved chewiness, EF9 and EF10 extruded well but exhibited some doughiness on eating. Composition EF11 extruded well and exhibited a pleasing texture. Composition EF12 gave a firm extrudable product with poorer eating than some of the other compositions. Compositions EF13 and EF14 were extremely mushy in texture. Composition EF15 gave similar properties to EF11, but with a less good, mushier, texture.

Based on the results, it was determined that compositions comprising a modified starch, protein extender and fiber exhibited the best combination of properties for a filling composition for a coated food product, with EF11 exhibiting the most promising properties of the compositions screened.

Example 2: Refinement of the filling composition

Further filling compositions were prepared and tested in the same manner as those of Example 1, but with co-extrusion into two alginate-based casing materials: one containing a glycerol plasticiser and a microcrystalline cellulose interrupting agent, and one containing a glycerol plasticiser and a tapioca starch interrupting agent. Details of the compositions and results of the testing are shown in Figure 2.

Composition EF16 exhibited excellent extrusion properties, but slightly poorer eating than EF11. Composition EF16 in which Elastitex™ was used in place of Purity™ exhibited good extrusion properties but slightly poorer eating than EF16. Where N-Hance® was used in place of Purity™, EF16 was far too firm and too dry, thereby suggesting that a modified starch is necessary for the optimum balance of extrusion and texture properties. Composition EF11, but with more fibre, exhibited very good extrusion and eating properties. Composition EF 11, but with more fibre and Almidon National™ 1317 in place of Firm-tex™, also exhibited very good structure for extrusion and eating properties.

Example 3: Further compositions

Two further filling compositions were prepared and tested using a modified method. The filling compositions were based on EF11, but with Almidon National™ 1317 or a combination of Almidon National™ 1317 and N-Hance® in place of Firm-tex™. Details of the compositions and results of the testing are shown in Figure 3.

Both filling compositions exhibited excellent extrusion and eating properties. The composition which contained Almidon National™ 1317 in combination with N-Hance®, i.e. an unmodified starch, was the slightly softer of the two compositions and exhibited the superior eating properties. The softening in the filling composition containing N-Hance® is believed to be as a result of the lower quantity of soy concentrate, fibre and modified starch, though the softening was largely compensated for by the use of N-Hance®.

Claims

1. A filling composition for a coated food product, said filling composition comprising:

animal matter;

protein extender;

modified starch;

fibre; and water.

2. The filling composition of Claim 1, wherein the filling composition comprises:

the animal matter in an amount of at least 25 %;

the protein extender in an amount of at least 2 %;

the modified starch in an amount of at least 3.5 %;

the fibre in an amount of at least 1 %; and water in an amount of at least 30 %, by weight of the filling composition.

3. The filling composition of Claim 2, wherein the filling composition comprises:

the animal matter in an amount of from 25 to 60 %;

the protein extender in an amount of from 2 to 7%;

the modified starch in an amount of from 3.5 to 9.5%;

the fibre in an amount of from 1 to 4.5%; and water in an amount of from 30 to 60%, by weight of the filling composition.

4. The filling composition of any of Claims 1 to 3, wherein the modified starch is a heatsensitive modified starch.

5. The filling composition of any of Claims 1 to 4, wherein the modified starch is derived from potato, maize, tapioca or wheat, and preferably from potato, maize or tapioca.

6. The filling composition of any of Claims 1 to 5, wherein the modified starch is starch in which -OH groups have been modified, e.g. esterified or etherified.

7. The filling composition of Claim 6, wherein the -OH groups have been esterified to give a group having the formula: -OC(O)Ri, where R> is selected from Ci.6 alkyl groups, and is preferably a methyl group.

8. The filling composition of Claim 6, wherein the -OH groups have been etherified to give a group having the formula: -OR2, where R2 is a C^e alkyl group or a C^e hydroxyalkyl group, and is preferably a hydroxy propyl group.

9. The filling composition of any of Claims 1 to 8, wherein the modified starch is starch which has been crosslinked, e.g. using a phosphate compound (e.g. sodium trimetaphosphate or phosphorus oxychloride) or an anhydride (e.g. adipic anhydride).

10. The filling composition of any of Claims 1 to 9, wherein the modified starch is selected from:

acetylated distarch adipate;

acetylated starch;

hydroxypropyl distarch phosphate; and Almidon National™ 1317.

11. The filling composition of any of Claims 1 to 10, wherein the composition comprises the modified starch in an amount of from 4 to 8.5 % by weight, and preferably from

4.5 to 7.5 % by weight of the filling composition.

12. The filling composition of any of Claims 1 to 11, wherein the composition further comprises unmodified starch in an amount of from 0 to 4 % by weight, preferably from 0.75 to 3.5 % by weight, and more preferably from 1.25 to 3 % by weight of the filling composition.

13. The filling composition of Claim 12, wherein the ratio of modified starch to unmodified starch in the filling composition is from 1 : 1 to 10 : 1, preferably from 1.25 : 1 to 8 : 1, and more preferably from 1.5 : 1 to 5 : 1 by weight.

14. The filling composition of any of Claims 1 to 13, wherein the protein extender is derived from soya beans, and preferably is a soya isolate or a soya concentrate.

15. The filling composition of any of Claims 1 to 14, wherein the protein extender is used in an amount of from 2.5 to 6 % by weight, and preferably from 3 to 5 % by weight of the filling composition.

16. The filling composition of any of Claims 1 to 15, wherein the fibre is derived from wheat or soya beans, and preferably is derived from soya beans.

17. The filling composition of any of Claims 1 to 16, wherein the fibre is used in an amount of from 1.5 to 4 % by weight, and preferably from 2 to 3.5 % by weight of the filling composition.

18. The filling composition of any of Claims 1 to 17, wherein the ratio, by weight, of protein extender to fibre is greater than 0.8 : 1, preferably greater than 1:1, and more preferably greater than 1.2 : 1.

19. The filling composition of any of Claims 1 to 18, wherein the animal matter comprises red meat, pork, poultry, fish or combinations thereof.

20. The filling composition of any of Claims 1 to 19, wherein the animal matter is shredded, minced, pureed or in the form of a paste.

21. The filling composition of any of Claims 1 to 20, wherein the animal matter is used in an amount of from 25 to 50 % by weight, and preferably from 30 to 45 % by weight of the filling composition.

22. The filling composition of any of Claims 1 to 21, wherein water is used in an amount of from 35 to 55 % by weight, and preferably from 40 to 50 % by weight of the filling composition.

23. The filling composition of any of Claims 1 to 22, wherein animal matter, water, protein extender, starch (modified and unmodified) and fibre together make up at least 90 % by weight, preferably at least 94 % by weight, and more preferably at least 96 % by weight of the filling composition.

24. The filling composition of any of Claims 1 to 23, wherein the filling composition further comprises a calcium compound and/or a phosphate compound.

25. A method for preparing a filling composition of any of Claims 1 to 24, said method comprising combining the following components:

animal matter;

protein extender;

modified starch;

fibre; and water.

26. A coated food product which comprises a filling composition according to any of Claims 1 to 24; and a coating material.

27. The coated food product of Claim 26, wherein the coating material comprises a polysaccharide, and preferably an anionic polysaccharide.

28. The coated food product of Claim 27, wherein the coating material comprises alginate.

29. The coated food product of any of Claims 26 to 28, wherein the coating material further comprises a plasticiser and an interrupting agent.

30. The coated food product of any of Claims 26 to 29, wherein the coating material is an aqueous coating material, preferably having a pH in the range of from 3.4 to 4.0.

31. The coated food product of any of Claims 26 to 30, wherein the coating material is obtainable by a method comprising:

(a) maintaining a coating material comprising an anionic polysaccharide at a pH of from 3.4 to 4.0 to increase its viscosity; and (b) homogenizing the coating material.

32. A method for preparing a coated food product, said method comprising:

applying an aqueous coating material to a filling composition as defined in any of Claims 1 to 24.

33. The method of Claim 32, wherein the aqueous coating material is as defined in any of Claims 27 to 31.

34. The method of Claim 32 or Claim 33, wherein the coating material is applied to the filling composition in an amount of from 0.5 to 20 % by weight, preferably from 1 to

10 % by weight, and more preferably from 2.5 to 5 % by weight of the filling composition.

35. The method of any of Claims 31 to 34, wherein the filling composition is co-extruded with the coating material.

36. The method of any of Claims 31 to 35, wherein the method further comprises:

strengthening the coating material by contacting the coated food product with group 2 metal ions.

37. The method of Claim 36, wherein the group 2 metal ions are selected from calcium ions, barium ions and magnesium ions, and preferably are calcium ions.

38. The method of any of Claims 31 to 37, wherein the method further comprises:

cooking the coated food product.

39. A coated food product obtainable by a method according to any of Claims 31 to 38.

40. A kit comprising:

protein extender, modified starch and fibre; and instructions for preparing a filling composition as defined in any of Claims 1 to 24 or a coated food product as defined in any of Claims 26 to 31.

41. The kit of Claim 40, wherein the kit further comprises:

a polysaccharide, and preferably a plasticiser and interrupting agent; and instructions for preparing a coating material as defined in any of Claims 27 to 31.

42. The kit of Claim 40 or Claim 41, wherein the components of the kit are in an anhydrous form.

43. Use of a filling composition according to any of Claims 1 to 24 in a coated food product.

44. Use of a combination of protein extender, modified starch and fibre for improving the extrusion and/or cooking and/or texture properties of a filling composition comprising water and animal matter.

45. An apparatus for preparing a coated food product, said apparatus comprising:

a tank in which a filling composition according to any of Claims 1 to 24 is held; and a coating device for coating the filling composition with a coating material.