GB2199725A - Improved method and apparatus for recovering chocolate - Google Patents

Abstract

Chocolate is recovered from broken and rejected chocolate biscuits by subjecting the biscuits to heat to melt the chocolate, followed by directing a fluid, eg a curtain of air at the biscuits to wipe the chocolate therefrom and collecting the displaced chocolate for re-cycling. The process may be carried out by trapping the biscuits between a pair of face to face wire conveyor bands, passing the trapped biscuits between infrared heaters above and below the bands, and by applying air jets above and below the biscuits. <IMAGE>

Description

Improved Method and Apparatus for Foodstuff Processing This invention relates to a method of and apparatus for the processing of foodstuff, in particular the recovery of chocolate from, for example, chocolate biscuits, which are of an unsuitable standard to be issued for sale. Such unacceptable standard biscuits, which can include parts of broken biscuits, are referred to hereinater as 11rejects'1 in the interests of simplicity, and unless the context otherwise admits or requires, "rejects'1 means unacceptable standard biscuits or parts thereof.Other articles which have chocolate coating include confectionery, cakes and the like, but in each case the relevant article will have a centre or core, or a portion, in the case for example of biscuits which are half chocolate coated, which is not chocolate or at least is of a different composition from the chocolate coating.

Thus, chocolate biscuits have a biscuit portion and a chocolate coating.

At present, rejects are simply gathered and fed to a grinding apparatus, which grinds and mills the rejects into fine particles of biscuit material and chocolate.

This ground and milled material is returned to the chocolate supply which is used for coating the biscuit portions in the production of chocolate biscuits.

This practise, although widely used in'the chocolate industry, presents a number of shortcomings and disadvantages, amonst which are the following.

1) The basic materials of biscuits are fat, flour, sugar and water. The chocolate material contains fat but the biscuit fat has a lower melting point than the chocolate fat. Biscuits with chocolate coatings containing recycled rejects therefore soften at lower temperature and often melt when held by hand due to the body heat transmitted through the fingers. Again, when milled rejects are included in the chocolate supply, the time it takes for the chocolate to set is increased compared to the time it takes for chocolate material without milled rejects to set.

2) Also, the control of the manufacture of the chocolate material is related critically to temperature, and the inclusion of biscuit fat in the chocolate by recycling the rejects, means that an already difficult manufacturing process is rendered even more difficult. When the process is supervised by a craftsman, the embodiment of milled rejects in the chocolate can be tolerated, as such a craftsman by eye, touch and taste will be able to adjust the control of the manufacture as it proceeds, without producing too much waste, but with the demise of such craftsmen and the increased use of computers for controlling the manufacture, difficulties can arise.

3) Many countries will not accept products with chocolate material containing milled rejects, or at least will not allow such products to be described as "chocolate". In fact the use of milled rejects in the chocolate material has contributed to there not being an internationally accepted standard for chocolate.

4) Any producer who embodies the milled rejects in his chocolate has restriction placed upon him as to how, in his advertising and marketing, he can describe the purity of the chocolate material.

In consequence, the present invention was made because of an examination of how to eliminate the use of rejects in chocolate material, especially for chocolate biscuits, but usable in connection with all chocolate articles having chocolate material to the exterior thereof.

The invention concerns a method and apparatus for recovering the chocolate from such articles and in accordance with the present invention an article having chocolate material to the exterior thereof is heated to soften the chocolate material and the chocolate in softened form is displaced from the article by means of a flow of fluid (which does not affect the chocolate) passing over the article, the displaced chocolate being suitably collected for recovery and re-use.

The said fluid is preferably warm so as not to solidify the chocolate as it is being displaced from the article.

The method may be used on a plurality of articles, for example articles being carried by a conveyor, simultaneously and the said fluid is preferably compressed air directed in the form of a narrow curtain at the articles as they pass the location whereat an air knife issuing said curtain is positioned.

Preferably, there will be two of said air knives symmetrically arranged above and below a horizontal plane along which the articles travel. The air knives are preferably arranged so that the air curtains issue at an angle to said plane and in displacing the chocolate from said articles in fact wipe or ripple the chocolate against the direction of travel of the articles. The chocolate therefore accummulates and drops off the trailing ends of the articles and falls through a wire band conveyor belt on which the articles are supported, and is collected in a collecting tray from whence it can be recycled to a chocolate enrober supplying the chocolate material to said article.

The air knives are preferably mounted for angular, height and lengthwise position adjustment to accommodate different types of articles.

The articles are preferably held between two of said wire bands arranged face to face whilst the chocolate in being displaced therefrom, and the environment surrounding the chocolate displacement area preferably is maintained at an elevated temperature to keep the displaced chocolate fluent.

By using two knives it is ensured that chocolate material at the top and bottom of the articles is displaced and recovered and of course if the articles have chocolate coating on one side only, no step need be taken to ensure that all of the articles face in the same direction.

Tests with the method on rejects have shown that 80% of the chocolate material can be recovered, the remaining 20% being in fact absorbed into the pores in the biscuit material. This biscuit material can, because it has such a low chocolate content, be recycled into the biscuit supply side of the process.

The chocolate material of the articles may be heated by passing the articles under and over heat sources such as infra red heat sources.

An embodient of the present invention will now be described, by way of example, with reference to the recovery of chocolate material from chocolate coated (one side or all over) biscuit rejects, and with reference to the accompanying drawings wherein:- Fig. 1 is a plan view of a chocolate material recovery plant; and Fig. 2 is a diagrammatic side view of the recovery system of the plant of Fig. 1.

Referring to the drawings, in Fig. 1 a chocolate material recovery plant is shown, and comprises sieve input station 10, a vibratory feed station 12 and a chocolate recovery station 14. Chocolate biscuit rejects from which the chocolate is to be recovered by the plant shown in Fig. 1 are placed in the sieve stage 10 so that loose crumb portions of biscuit in the reject batch will fall through the sieve and can be collected and removed from the system and the rejects when they reach the chocolate material recovery stage 14 should be as crumb free as possible. From stage 10, the rejects pass to stage 12 in which the rejects are vibrated, further to assist removing crumbs which may be sticking to the reject biscuits, and in addition the rejects are spread out, preferably so as to be out of contact with each other. It should be mentioned at this stage that the rejects are suppor-ted on a wire band of the type conventionally used in chocolate processing plants comprising parallel wire strip portions with spaces therebetween through which molten chocolate can pass.

Fig. 2 shows the chocolate material recovery stage 14 in greater detail. The direction of movement of the biscuit rejects of which one is illustrated at 16 and another at 18, is indicated by the arrow 20. The said wire band is shown at 22 and the biscuit rejects rest on the upper reach 24 thereof.

In the first section of the chocolate material removal stage 14, the rejects 16 are carried between upper and lower light and heat sources 26 and 28 which serve to soften the chocolate coating on the biscuit reject 16.

As the rejects 16 pass progressively through the space between the sources 26 and 28, so the chocolate coating softens until it reaches such a viscosity that it can in fact be wiped off the biscuit material of the reject which is precisley what is done in the second portion of the chocolate material removal stage 14.In that second stage, a second wire band 30 is brought into utilisation, and a lower reach 32 thereof is caused to engage the upper side of the reject 16 or in the case of Fig. 2 reject 18 and whilst the rejects are so held by the band reaches 24 and 32 and travel as indicated by arrow 20, curtains of air are applied from air knives 34 and 36 at an appropriate angle 38 to the horizontal plane in which the rejects travel so as to wipe the chocolate material such as that indicated by reference numerals 40 and 42 from the upper and lower surfaces of the reject 16 (assuming that the rejects are covered top and bottom with a chocolate coating).

If only one side is coated, then the chocolate will be removed as indicated by reference 40 or reference 42 as the case may be. As the rejects 18 continue to travel past the knives 34 and 36, so the chocolate material is wiped clear of the reject and falls through the upper reach 24 of belt 22 into a collecting tray 44 in which the lower reach 46 of the band 22 travels as indicated by the direction of arrow 48. The movement of this reach in fact feeds the chocolate to a chocolate recovery outlet 50.

The rejects 18 stripped of the chocolate coating emerge at the location 52 and then as indicated by arrow 54 are discharged to a conventional grinding and milling machine in which they are ground and milled to produce material which can be re-cycled to the biscuit supply side of a chocolate biscuit manufacturing plant.

The air which issues from the knives 34 and 36 is in the form of a narrow curtain extending for the width of the bands 22 and 30 (which are of equal width) and the air is heated in order to ensure that the displaced chocolate 40 and 42 will not solidify before reaching the outlet 50. In fact it may be desirable to maintain the whole of the environment surrounding the recovery stage 14 at an elevated temperature in order to prevent the chocolate solidification.

The angularity of the knives 34 and 36 can be adjusted as required as can the position of the knives in vertical and horizontal directions, and the knives are indpenedently adjustable.

The screen 54 is provided to prevent chocolate splashings from reaching the heat sources 26 and 28.

The knives 34 and 36 are preferably totally enclosed in suitable casings in order to maintain the elevated temperature of the air and the air flow should be set so as to give high volume low velocity output. The width of the air curtain may be of the order of 1 or 2 mm.

The chocolate material on the rejects must be heated to a sufficient temperature, for example in the order of 300C to achieve the fluency necessary, but the heating should not be so high as to burn or carmalise the chocolate.

Using infra red heat sources 26 and 28 the speed of the belt 22 may be arranged so that a temperature of approximately 300C is achieved at the end of the run through the heat sources when the run takes of the order of half a minute.

The recovered chocolate can be returned and mixed with the chocolate being used for the production of chocolate coated articles, provided that the recovered chocolate is returned as quickly as possible and certainly before the elapse of a period which is in fact relatively long (of the order of two weeks).

By using the method according to the present invention, a producer will be applying to his articles always chocolate of the same consistency, and he can claim a much higher purity for the chocolate coatings. This should enable him to supply his chocolate coated articles to a much wider range of territories, and control of the production can be automated much more readily than when milled rejects are returned to the chocolate supply.

Claims (10)

1. A method of recovering chocolate from chocolate coated articles wherein an article having chocolate material to the exterior thereof is heated to soften the chocolate-material and the chocolate in softened form is displaced from the article by means of a flow of fluid (which does not affect the chocolate) passing over the article, the displaced chocolate being suitably collected for recovery and re-use.

2. A method according to claim 1, wherein the said fluid is warm.

3. A method according to claim 1 or 2, wherein a plurality of articles are treated simultaneously and wherein the articles are carried on an open mesh conveyor.

4. A method according to claim 3, wherein said fluid is compressed air and is directed in the form of a narrow curtain at the articles as they pass the location whereat an air knife issuing said curtain is positioned.

5. A method according to claim 4, wherein there are two of said air knives symmetrically arranged above and below a horizontal plane along which the articles travel.

6. A method according to the claim 5, wherein the air knives are arranged so that the air curtains issue at an angle to said plane and in displacing the chocolate from said article in fact wipe or ripple the chocolate against the direction of travel of the articles.

7. A method according to claim 5 or 6, wherein the air knives mounted for angular, height and lengthwise position adjustment to accommodate different types of articles.

8. A method according to any of claims 2 to 7, wherein the articles are held between two wire band conveyors arranged face to face whilst the chocolate is being displaced therefrom.

9. A method according to any preceding claim, wherein the environment surrounding the chocolate displacement area is maintained at an elevated temperature to keep the displaced chocolate fluent.

10. Apparatus for recovering chocolate from chocolate coated articles comprising heating means for heating the chocolate coated articles to soften the chocolate material, means for displacing the chocolate when in softened form from the articles, such means creating a flow of displacement fluid, and collection means for coollecting the displaced chocolate for recovery and re-use.