GB2306289A

GB2306289A - Chocolate forming

Info

Publication number: GB2306289A
Application number: GB9522162A
Authority: GB
Inventors: Stephen Thomas Beckett; Mark Jury; Malcolm Robert Mackley
Original assignee: Societe des Produits Nestle SA; Nestle SA
Current assignee: Societe des Produits Nestle SA; Nestle SA
Priority date: 1995-10-30
Filing date: 1995-10-30
Publication date: 1997-05-07
Also published as: ZA969086B; CO4750769A1; UA41400C2; SG81902A1; JPH1056970A; GB9617652D0; MY115857A; AR004525A1; GB9522162D0

Abstract

A process for forming an extruded fat-containing confectionery material which comprises feeding the fat containing confectionery material 14 into an extrusion devices 10 and applying pressure to the fat-containing confectionery material in a substantially solid or semi-solid non-pourable or non-flowable form upstream of a flow constriction whereby the temperature, pressure, contraction ratio and extrusion rate are such that the fat-containing confectionery material is extruded substantially isothermally and remains in a substantially solid or semi-solid non-pourable or non-flowable form and which has a temporary flexibility or plasticity characterised in that, while the extruded product 22 exhibits the temporary flexibility, passing the extruded product between the nip of a pair of counter-rotating rollers 18 provided with corresponding circumferential depressions 19 to plastically form the extruded product into the shape 23 conforming to the shape of the nip and releasing the formed product from the nip of the pair of rollers.

Description

CHOCOLATE FORMING The present invention relates to the forming of chocolate into a desired shape more particularly to a process for forming of chocolate in a solid or semi-solid state.

One method of forming chocolate into a desired shape is by moulding. Moulding of chocolate is normally carried out in the liquid state by casting, i.e. pouring the molten chocolate into a mould followed by cooling. The moulded chocolate is usually demoulded quite easily after cooling, due to the thermal contraction of the chocolate as it sets, giving a product with an attractive glossy surface.

However, the disadvantages of conventional chocolate moulding are the requirement for cooling tunnels which consume space and time, the product cannot be wrapped directly because of the cooling step and it is not possible to achieve exact weight control. The formation of the chocolate centres for "Smarties" (RTM), currently involves the use of rollers which also require a very high cooling capacity.

In our co-pending EP-A-93114251.7 we describe a process for plastically extruding a fat-containing confectionery material which comprises feeding the fat containing confectionery material into an extrusion device and applying pressure to the fat-containing confectionery material in a substantially solid or semi-solid nonpourable form upstream of a flow constriction whereby the temperature, pressure, contraction ratio and extrusion rate are such that the fat-containing confectionery material is extruded substantially isothermally and remains in a substantially solid or semi-solid non-pourable form to produce an axially homogeneous extruded product and which has a temporary flexibility or plasticity enabling it to be physically manipulated or plastically deformed e.g. it can be bent, twisted or forced into a mould. EP-A-93114251.7 also describes an injection moulding process where the temporary flexible extruded product is injection moulded under pressure at a temperature below the normal melting point of chocolate. This injection moulding process is substantially isothermal and subsequent cooling is therefore unnecessary so that the product is suitable for demoulding immediately after the injection moulding is complete. However, because a subsequent cooling is not necessary, thermal contraction does not necessarily occur and, in some circumstances, demoulding and obtaining a high quality surface finish may be difficult to achieve.

We have now found, surprisingly, that it is possible to form the solid or semi-solid non-pourable or non-flowable extruded chocolate into a variety of shapes by passing the extruded chocolate between the nip of a pair of counterrotating rollers from which the shaped chocolate is easily released and has an attractive smooth surface.

Accordingly, the present invention provides a process for forming an extruded fat-containing confectionery material which comprises feeding the fat containing confectionery material into an extrusion device and applying pressure to the fat-containing confectionery material in a substantially solid or semi-solid non-pourable or nonflowable form upstream of a flow constriction whereby the temperature, pressure, contraction ratio and extrusion rate are such that the fat-containing confectionery material is extruded substantially isothermally and remains in a substantially solid or semi-solid non-pourable or nonflowable form and which has a temporary flexibility or plasticity, characterised in that, while the extruded product exhibits the temporary flexibility, the extruded product is passed between the nip of a pair of counterrotating rollers provided with corresponding surface depressions to plastically form the extruded product into the shape conforming to the shape of the nip and releasing the formed product from the nip of the pair of rollers.

Counter-rotating rollers suitable for use in the process of the present invention are commonly used in the food and pharmaceutical industry for a range of products, e.g.

boiled sweets, chocolate lentils (Smarties centres), biscuits and drug capsules. The cavity formed by the two corresponding circumferential depressions of the rollers may be almost any desired shape, provided there are no "negative angles" which would prevent the shaped product from releasing from the cavity, e.g. spherical, ovoid, discoid or cubic. In addition, the surface of the cavity may be engraved or embossed with any desired pattern which is to be imparted to the surface of the fat-containing confectionery material.

It should be understood that the temporary flexibility or plasticity of the extruded product enables the product to be physically manipulated or plastically deformed before it loses its flexibility or plasticity, so that it may completely fill the cavity in one piece without leaving gaps or without crumbling in the cavity.

The details of the extrusion of the fat-containing confectionery material are described in our co-pending EP A-93l122Sl.7 whose disclosure is hereby incorporated into the present specification.

By "substantially isothermally" in this invention we mean that the temperature of the fat-containing confectionery material remains substantially unchanged under the conditions of the extrusion from the input to the outlet of the flow constriction and during forming if there is no external heating or cooling means: the use of external heating or cooling means is not excluded as long as the material being extruded remains in a substantially solid or semi-solid non-pourable or non-flowable state throughout the extrusion and forming. In other words, the temperature of the fat-containing confectionery material is not caused to increase substantially by the extrusion or forming process itself.

The fat-containing confectionery material may be, for instance, plain, white or milk chocolate or chocolate substitutes containing direct cocoa butter replacements, stearines, coconut oil, palm oil, butter or any mixture thereof; nut pastes such as peanut butter and fat; praline; confectioner's coatings used for covering cakes usually comprising chocolate analogues with cocoa butter replaced by a cheaper non-tempering fat; or "Caramac" comprising non-cocoa butter fats, sugar and milk.

The forming temperature may be from as low as 0 C to about 35"C depending on the composition, particularly the amount and type of fat present. When plain chocolate is used as the extruded feed material, the forming temperature may be from 10 to 34"C, more usually from 15 to 32"C, preferably from 18 to 30"C and more preferably from 200 to 27"C. In the case of white chocolate, the forming temperature may be from 5" to 28"C, more usually from 15 to 27"C, preferably from 17 to 26"C and more preferably from 19 to 2500. In the case of milk chocolate, the forming temperature may be from 5"C to 300C, more usually from 15"C to 28"C, preferably from 18 to 270C and more preferably from 20 to 26"C. It should be understood that, in this invention, when the chocolate is formed at a temperature from 280 to 34"C it is in a solid or semi-solid non-pourable or non-flowable state after being previously set hard in contrast to chocolate which has not been previously set hard such as recently tempered chocolate which is usually still pasty and pourable or flowable at such temperatures.

The formed product emerges from the nip of the counterrotating rollers as a series of shaped sweets which are normally and advantageously held together by a thin web of fat-containing confectionery material, e.g. having a thickness of from 50 to 100 microns. The presence of this web helps to pull or demould the sweets from the cavity surface of the rollers. It is not essential to have a web holding the sweets together. However, if there were no web, in order to obtain separated sweets, the rollers would have to be held together under a very high pressure and this would lead to increased wear of the rollers in a continuous operation.

The rollers may, if desired, be cooled, for instance by means of the circulation of a cooling medium e.g. water through the central axis of each roller. However, because the fat-containing confectionery material is substantially solid or semi-solid and, therefore, already at a relatively low temperature, e.g. below about 35or, a high cooling capacity is not required. However, a slight cooling, e.g.

by up to 5oC, may improve the release of the shaped product from the cavity by preventing sticking.

After emerging from the nip of the counter-rotating rollers, the series of shaped sweets held together by the thin web is advantageously treated to remove the web, for example, by feeding into a rotating cylindrical sieve to remove the web by a tumbling action to leave separate sweets. The sweets may then be packed or fed to a further downstream process.

The forming process of the present invention is much easier to control and there is significantly improved weight control consistency when compared with normal shell moulding using molten chocolate. In addition, in contrast to most other chocolate moulding processes, the final product does not require cooling after the forming has occurred. Moreover, the formation of chocolate centres for "Smarties" (RTM) may be carried out without the requirement for the high cooling capacity of the current roller system.

As stated above, in EP-A-93114251.7 chocolate is injection moulded directly into a metal or plastics mould. However, if cold injection moulding is used as described therein, the resulting product does not consistently release due to the lack of contraction in the mould. The current invention overcomes these disadvantages by the use of the counterrotating rollers which prevents the chocolate from sticking to the cavity surface formed by the two corresponding circumferential depressions of the rollers.

The rollers may be made of a suitable rigid material such as metal, e.g. steel or a plastics material, e.g.

polycarbonate.

The final shape of the formed product depends on the shape of the cavity and its surface features.

The present invention will now be further described by way of example only with reference to the following drawings in which Figure 1 illustrates an apparatus for carrying out the process of the present invention.

Referring to the drawing, an extrusion device 10 comprises a hydraulically driven ram 11, a barrel 12 having an internal diameter of 25 mm, a hopper 13 containing chocolate buttons 14, a feed opening 15 and an extrusion die 16 with a nozzle 17 having a cross-section of 5 mm diameter. A pair of counter-rotating rollers 18 are provided with circumferential depressions 19 which correspond at the nip to form a cavity 20 downstream of which is a cylindrical sieve 21 rotating on its horizontal axis.

In operation, the chocolate buttons 14 are fed through the feed opening 15 into the barrel 12 and the hydraulic ram 11 is advanced at a pressure of 80 bars and at a temperature of 23 C. A semi-solid non-pourable rod 22 of chocolate of 5 mm diameter is extruded through the nozzle 17 which is then fed into the nip of the counter-rotating rollers 18 where it passes through the cavity 20 and is formed and then released from the cavity as a series of shaped sweets 23 held together by a web 24 of chocolate. On passing through the rotating sieve 21, the web 24 is removed by a tumbling action and the chocolate sweets 25 are separated and released for packaging or further processing.

Claims

1. A process for forming an extruded fat-containing confectionery material which comprises feeding the fat containing confectionery material into an extrusion device and applying pressure to the fat-containing confectionery material in a substantially solid or semi-solid nonpourable or non-flowable form upstream of a flow constriction whereby the temperature, pressure, contraction ratio and extrusion rate are such that the fat-containing confectionery material is extruded substantially isothermally and remains in a substantially solid or semisolid non-pourable or non-flowable form and which has a temporary flexibility or plasticity characterised in that, while the extruded product exhibits the temporary flexibility, passing the extruded product between the nip of a pair of counter-rotating rollers provided with corresponding circumferential depressions to plastically form the extruded product into the shape conforming to the shape of the nip and releasing the formed product from the nip of the pair of rollers.

2. A process according to claim 1 characterised in that the formed product emerges from the nip of the counter-rotating rollers as a series of shaped sweets.

3. A process according to claim 2 characterised in that the series of shaped sweets are held together by a thin web of fat-containing confectionery material.

4. A process according to claim 1 characterised in that the surface of the cavity formed by the two corresponding circumferential depressions of the rollers is engraved with a pattern.

5. A process according to claim 1 characterised in that the rollers are cooled

6. A process according to claim 1 characterised in that the rollers are cooled by means of the circulation of a cooling medium through the central axis of each roller.

7. A process according to claim 5 characterised in that the rollers are cooled by up to 50C.

8. A process according to claim 3 characterised in that the series of shaped sweets held together by the thin web is treated to remove the web.

9. A process according the claim 3 characterised in that the series of shaped sweets held together by the thin web is treated by feeding into a rotating sieve to remove the web by tumbling action.

10. A formed fat-containing confectionery material whenever prepared by a process according to any of the preceding claims.

11. A process for forming an extruded fat-containing confectionery material substantially as hereinbefore described with reference to the drawings.