The present invention relates to an edible composition, particularly to an edible composition useful as a barrier to the migration of a foodstuff component, such as a fat.

In composite foodstuffs, such as composite confectionery items, it may be desirable to prevent the migration of a component of one element into the other element. For example, in the case of a confectionery item comprising a core with a relatively high soft fat content, such as a praline core, and a coating such as chocolate, it may be desired to prevent migration of fat from the core into the coating. In the case of a chocolate coating, migration of fat into the chocolate coating can lead to the formation of a fat bloom on the surface of the coating; although the bloom is harmless, it is aesthetically undesirable. Fat migration may also adversely affect the texture of a confectionery product; for example, chocolate into which fat migrates may soften.

It has been proposed, for example in EP-A-O 547 551 , to provide a barrier against moisture migration in the form of a film of starch. Although such a film may be effective as a barrier, it is a solid layer within the foodstuff and is detectable during consumption of the foodstuff, with a deleterious effect on the taste and texture properties of the foodstuff.

It has been desired, therefore, to provide a barrier composition for use in foodstuffs which has little or no effect upon the organoleptic properties of the foodstuff and is effective to prevent migration of a component from one element of the foodstuff to another. According to the invention there is provided a barrier composition for use in foodstuffs comprising from 1% to 40% by weight of starch having a degree of polymerisation of no more than 90 and from 40% to 90% by weight of a plasticizer for the starch, the ratio of starch to plasticizer being no more than 1 :1.5.

The type of starch employed is not believed to be of particular importance; for example, the amylase/amylopectin ratio of the starch is not believed to be important. It is preferred that the degree of polymerisation (DP) of the starch is no lower than 5, more preferably no lower than 10, but starches having lower DP values may be used. The starch may be a modified starch.

A preferred plasticizer is glycerol. Other preferred plasticizers include dihydric alcohols, such as ethylene glycol and propylene glycol. Preferably, the starch to plasticizer ratio is no more than 1 :3, preferably no more than 1 :4, more preferably no more than 1 :6, still more preferably no more than 1 :8. Preferably, the ratio is no less than 1 :20, more preferably no less than 1 :12, more preferably no less than 1 :10.

The barrier composition preferably includes up to 40% by weight of a bulking agent, which may impart a desired flavour to the composition. A preferred bulking agent is fructose. Other preferred bulking agents include other mono- and di-saccharides. Other edible components which do not significantly affect the viscosity of the composition may be used as bulking agents.

The barrier composition may include up to 10% by weight of water. The water content affects the viscosity of the barrier composition and can be used to control it. The barrier compositions of the invention are liquid at the point at which they are applied to the foodstuff, so that conventional confectionery manufacturing techniques such as enrobing or the so-called triple shot deposition technique can be used to apply them. Preferably, the viscosity of the barrier compositions of the invention at the point of application is from 5Pa s to 600Pa-S, preferably from 10OPa-S to 400Pa-S. Viscosity measurements are made on an Advanced Rheometer AR100 parallel plate rheometer at a constant shear rate of 1000Pa, using a 40mm flat (0 ^° ) steel probe and a gap of 1mm, at 25°C.

The invention also provides a composite foodstuff comprising first and second foodstuff elements having different fat compositions and/or contents from each other and a barrier composition according to the invention between them. The elements may contain different fats, different amounts of fat or both. Preferably, the first element is a core and the second foodstuff element is a coating around the core; more preferably, the core has a higher liquid fat content than the coating.

Preferably, the first element is a soft fat based core, such as a confectionery cream (not necessarily a dairy cream). A typical confectionery cream has a composition as follows: at least 25% soft fat comprising at least 20% liquid fat at 2O ⁰ C (that is, a higher proportion and a softer fat than cocoa butter in chocolate); an emulsifier such as lecithin or PGPR; and other bulking ingredients such as sugar or other mono- and di- saccharides, polyols, skimmed milk powder or other food ingredients. Preferably, the second foodstuff element is a fat based coating such as a coating of chocolate, a chocolate compound (a chocolate flavour material not conforming to the usual definition of chocolate, usually containing less cocoa butter than chocolate or no cocoa butter) or a chocolate equivalent (a material containing little or no chocolate but with similar flavour and texture). In a particularly preferred foodstuff, the coating is chocolate. The invention also provides a method of making a barrier composition according to the invention comprising dissolving the starch in the plasticizer and heating the solution, preferably at between 120 ⁰ C and 160 ⁰ C. If water is to be added, it is added with the plasticizer. The bulking agent is preferably added after the starch has dissolved.

The invention will be further described by way of example, with reference to the drawings in which:

Figure 1 shows a cross section through a confectionery product according to the invention; Figure 2 shows schematically a first apparatus for making the confectionery product of Figure 1; and

Figure 3 shows schematically a second apparatus for making the confectionery product of Figure 1. The invention will be described in part with reference to the manufacture of a chocolate coated praline having a soft fat based core. It will be readily appreciated that the invention finds application in other foodstuffs where a barrier to liquid fat is required, particularly a barrier to liquid fat migration from a high liquid fat content element of the foodstuff.

A chocolate coated praline 10 according to the invention, shown in Figure 1 , comprises a praline core 12 as the first element and a chocolate coating 14 as the second element. Since the liquid fat content of the praline core is higher than that of the chocolate coating, in a conventional chocolate coated praline fat would migrate from the core to the coating, leading to the formation of an undesirable fat bloom on the surface of the coating and softening of the coating. In the chocolate coated praline of the invention, a layer 16 of the barrier composition of the invention is disposed between the praline core 12 and the chocolate coating 14. The barrier layer 16 prevents migration of fat from the core 12 to the coating 16, so that the chocolate coated praline 10 may be stored without the formation of bloom on the coating.

Barrier compositions according to the invention may be made as follows:

The starch component is dissolved in the plasticizer by heating them together at from 120 ⁰ C to 160 ⁰ C in a in a jacketed vessel with a low shear propeller mixer until the solution clears (this typically takes up to 10 minutes depending on the quantities and the vessel used). The water content, if any, is reduced by this heating. Any bulking agent employed is added to the heated solution. The solution is then cooled to ambient temperature. Low shear mixing is preferred to high shear mixing to avoid reducing the degree of polymerisation of the starch. Table 1 shows exemplary barrier compositions according to the invention. In the table:

HPS is thinned hydroxypropylated starch;

GLY is glycerol;

SUC is sucrose;

FRU is fructose. CRY is Crystal-Tex626 (trade mark), a tapioca dextrine product supplied by National

Starch & Chemical; and

GLU13 is Glucidex12 (trade mark), a maize maltodextrine product supplied by Roquette Freres having a DE (dextrose equivalency) of 12, corresponding to a DP (degree of polymerisation) of about 16. Table 1

The barrier compositions of the invention are relatively viscous liquids when prepared. They can be applied to a foodstuff element by any method used in the preparation of foodstuffs to coat such a liquid into a substrate. Preferred methods include enrobing and the triple shot deposition method.

The application of barrier compositions according to the invention will be further described, by way of example, with reference to the preparation of chocolate coated pralines; generally spherical cores of praline with a thin chocolate coating, of the type shown in Figure 1. It will be appreciated that the barrier compositions can be applied to other foodstuff elements and by other application techniques.

Example 1 ; enrobing:

Praline cores are prepared by mixing 27.5% by weight icing sugar and 22.5% by weight skimmed milk powder in a Hobart mixer. To this mixture, 24.8% by weight of molten soft fat at 30 ⁰ C is slowly added with mixing to form a dry paste. The dry, crumbly paste is refined in a roller refiner until the particle size is reduced to no more than about 14μm. A further 24.7% by weight of the molten fat is added to the paste, with mixing to produce an homogenous liquid paste. The paste is refrigerated until use. The outer coating used in the preparation of the coated pralines is conventional milk chocolate made having the following composition: sucrose 54% cocoa butter 22.7% whole milk powder 13% cocoa liquor 10% lecithin 0.25% vanillin 0.05%

The chocolate is refined to a particle size below 14μm.

A barrier composition for use in the preparation of the coated pralines by an enrobing technique is made by adding 11.3% by weight thinned hydroxypropylated starch (C*AraSet 75701 (trade mark) , supplied by Cargill pic) is added to 59.3% by weight of glycerol and heated to 150 ⁰ C to dissolve the starch. 29.4% by weight fructose is added to the solution, which is then cooled to 30 ⁰ C. The barrier composition has a viscosity of 145Pa s at 25°C measured as described above.

To the praline made as described above is added 5% by weight sunflower oil and 10% by weight wafer inclusions, based on the weight of praline, before use to make coated pralines. Coated pralines according to the invention may be made on an enrobing apparatus 20 of the type shown schematically in Figure 2. Cores of the praline are formed by introducing the praline paste from a paste hopper 22 sequentially into a plurality of moulds 24 (of which four exemplary moulds are shown in Figure 2) in the surface of a mould drum 26 rotating in the direction shown by the arrow in Figure 2. The core paste is introduced into a mould 24 when the mould is at its highest point; the filled mould is carried by the drum to its lowest point, at which point the moulded core is released onto a continuous belt 28 (the upper run only of which is shown in Figure 2). The cores 30 are conveyed on the belt 28 onto a first continuous mesh belt 32 (the upper run only of which is shown in Figure 2) which conveys the cores through a curtain of the barrier composition, at about 30 ⁰ C to about 50°C, released from a barrier hopper 34 above the mesh belt 32 to coat the core with the barrier composition. The drum 26 is cooled so that the surfaces of the cores 30 are at about -10 ⁰ C as they pass through the curtain of barrier composition. The thickness of the barrier composition coating is brought down to about 0.5mm in any suitable way, such as by application of an air knife 36 operating at up to about 5 bar. At this stage, the temperature of the barrier coated cores is about -5°C and the barrier composition is sufficiently solidified on the cores to allow the barrier coated cores to be transferred to the next stage of the manufacturing process while maintaining an even, continuous barrier coating.. The barrier coated cores are then carried by the first mesh belt 32 to a second continuous mesh belt 38 (the upper run only of which is shown in Figure 2) which conveys them through a curtain of the liquid tempered milk chocolate, at about 28 ⁰ C, released from a chocolate hopper 40 to provide an outer coating of chocolate. The thickness of the chocolate coating is brought down to about 6mm by application of an air blower 42, operating at up to

2 bar. The surfaces of the coated pralines are at about 15°C at this stage. They are carried by the second mesh belt 38 to another continuous belt 44 (the upper run only of which is shown in

Figure 2) into a refrigeration zone 46 where their temperature drops to about 10 ⁰ C, after which they are removed from the belt for packaging and storage. The process is conducted so that the ratio of core to chocolate in the finished coated product is about 3:2.

After storage for 32 weeks at 20°C, there was no apparent fat bloom on the surface of the coated pralines and the chocolate coating had not softened. The wafer inclusions remained crisp.

Example 2; triple shot deposition: A barrier composition is made by adding 12.8% by weight of thinned hydroxypropylated starch (C*Araset 75701 (trade mark), supplied by Cargill pic) to a solution of 54.5% by weight of glycerol in 4.8% by weight of water and heating the mixture to 150 ⁰ C to dissolve the starch in the glycerol solution. 27.9% by weight of fructose is added, and the mixture cooled to 30°C.

Coated pralines were made using a Winkler & Dϋnnebier Sϋβwarenmaschinen GmbH WDS 163.02 depositor. A triple shot depositor 50 is shown schematically in Figure 3. The praline, barrier composition and liquid tempered chocolate are supplied to three separate hoppers 52a, b, c respectively. The praline and the chocolate coating have the same compositions as those of Example 1. The praline, barrier composition and liquid tempered chocolate are led from the hoppers through respective pipes 54a, b, c to, respectively, the inner 56a, middle 56b and outer 56c of three concentric deposition nozzles in the machine, and deposited into moulds 58 passing continuously on a belt 60 under the nozzles 56a, b, c to form coated pralines having a praline core, a barrier coating and an outer chocolate coating. The flow of each component is interrupted and timed so that the praline core is coated by the barrier composition and the barrier composition is coated by the chocolate as the materials enter a mould 58 to form coated pralines 62. The moulds may be cooled to accelerate setting of the chocolate coating. The coated pralines are removed from the moulds for packaging and storage.

In this example, the temperatures of the materials in the hoppers 52a, b, c and in the nozzles 56a, b, c were held between 27°C and 31 ⁰ C. The flow to the nozzles was adjusted to produce chocolate coated pralines consisting of 33% by weight praline, 50% by weight of chocolate and 17% by weight of barrier composition. Performance of the chocolate coated pralines according to the invention made by the triple shot deposition process was compared with that of reference chocolate coated pralines of similar composition but without the barrier layer; the ratio of core to chocolate coating was the same in both samples The hardness of the chocolate coating of the pralines of the invention increased continuously over the 32 weeks (at 18°C over which they were studied, whereas the hardness of the chocolate coating of the reference pralines decreased markedly over the first three weeks and then remained stable. This indicates that fat has migrated from the core of the reference pralines into the chocolate coating, softening it, and that this has not occurred in the coated pralines of the invention. The hardness of the chocolate coating was determined as follows:

The product, stored at 18C°, is placed in a cabinet at 20 ⁰ C at least 2 hours prior to measurement to temper. Texture analyser (Stable Microsystems Ltd TA2XTi) with a 45° steel cone was used to measure chocolate shell hardness. The probe test speed was set to 1 mm/s. The force at 1 mm penetration of the probe into the chocolate coating was recorded. The results were as follows:

Time/weeks Invention/N Reference/N

3 0.43 0.27

6 0.46 0.27

15 0.53 0.26

32 0.62 0.25

It is apparent from the results that the chocolate coating of the reference pralines decreased slightly over the 32 week storage period, as would be expected because of the effect of liquid fat migrating into the coating from the core. It is also seen that the chocolate coating of pralines of the invention hardened over the same period, indicating that no fat migrated from the core into the coating.

It was also noted that the stability of the chocolate coating of the coated pralines of the invention is superior to that of the reference pralines. Heat stability comparisons were made at 15 and 32 weeks after manufacture. The pralines according to the invention were stable at 35°C, whereas the reference pralines collapsed at this temperature.

It will be seen that the invention provides a barrier composition for foodstuffs which has little or no effect upon the organoleptic properties of the foodstuff and is effective to prevent migration of a component from one element of the foodstuff to another, and foodstuffs incorporating such a barrier composition, and a method for making such a barrier composition.