Description

The present invention relates to a method and an apparatus for covering edible products, in particular for pan coating said products. Although the invention relates to the coating of edible products in general, for the sake of convenience specific reference will be made in the present description to pan coating, which represents the preferred embodiment of the invention.

Prior art

Products covered with sugar-based coverings or coatings, consisting of an edible central part and an edible outer part called the sugar coating, are well known.

The central part can consist of hard-boiled or chewy candy, chewing gum, almonds or other nuts, or chocolate.

The outer part mainly consists of sugar, which is increasingly often replaced by polyalcohols and other additives.

The finished product (center plus coating) is usually called dragee.

Method and ingredients

According to the pan coating method, the a number edible central parts, also called the centres or cores (the term which will be used hereafter in this description), are loaded into a machine called the coating pan, the essential element of which is a portion called "drum" that is usually cylindrical, onion shaped, or the like. Said coating pan drum rotates on its axis placed horizontally during the coating procedure, hence is also called "rotatable drum".

A suitable amount of sugar syrup is applied to quantity the cores while the coating pan drum rotates. The syrup, usually consisting of water, sugar and typically binders, such as gum arabic and maltodextrin, is dispersed uniformly over the surface of the cores due to the friction between them during rotation; in the hard coating technique, after a suitable time, the moisture is evaporated with an airstream, while the syrup crystallises on the cores.

To facilitate crystallisation, and consequently water evaporation, crystallising agents, usually in the form of an impalpable powder, are applied to the wet syrup in one or more of the layers making up the coating.

This procedure can be summed up in the following stages:

a) introduction of a quantity of edible cores to be coated into the rotatable drum of a coating pan, and start of drum rotation.

b) introduction into said drum on to the cores of material for coating said cores, in the form of liquids (syrups) and powder;

c) blowing of air into the drum and simultaneous suction from it of air mixed with powder, stages b) and c) being repeated at least once (in practice up to 50 times), until a coating of the desired weight and thickness, consisting of a plurality of layers, is obtained. Flavourings and colorants are typically added to the syrup.

According to the conventional technique, pan coating can be divided into four sequential steps following loading of the cores into the drum. Each step can consist of a plurality of repetitions of the above-mentioned stages b) and c). Said steps differ in terms of the constitution of the syrups, the use of powder and other process conditions:

1. Gum-coating: in this first step, the syrup applied is particularly rich in binders such as gum arabic or gelatin, in order to bind the rest of the sugar- coating to the core. This step is optional.

2. Engrossing: in this second step the syrup has fewer binders than in the previous step, but is richer in sugar or a sugar substitute. In this step, powder is also usually applied.

3. Smoothing: the syrup is more dilute in this step, than in the preceding ones, usually with few or no binders. The purpose is to give the dragee a smooth finish. Powder is not generally used. This part is also optional, but in practice is used in most industrial processes.

4. Polishing: in this last step syrup is not used, but a polishing agent such as carnauba wax, shellac or candelilla, to give the product a glossy finish and protect it against humidity.

Finally, the coated (sugar-coated) products (dragee) are unloaded from the coating pan and sent for subsequent processing.

To obtain sugar-free products, polyalcohols such as sorbitol, xylitol, isomalt, maltitol, mannitol or lactitol are used, either alone or in combination with one another. The method of obtaining the coating is substantially the same as for sugar-coated products.

Further information on conventional sugar-coating systems will be found in "The Science & Art of Candy Manufacturing", CD. Barnett, Magazines for Industry Inc. (1978) Chapter 10.

A particular embodiment of the present invention relates to sugar-free chewing gum. Information on the state of the art will be found in "Sugar Confectionery Manufacture", 2nd edition, E.B. Jackson ed., (1999), Chapter 12, and Silesia confiserie Manual no. 4, J.A. Merl, K.W. Stock (1996) Silesia Gehard Hanke KG ed.

When making chewing gum pellets according to the prior art, a chewing gum is made comprising a core formed by a gum base to which one or more sweeteners are added; the chewing gum centre is then covered with a coating based on one or more layers of sugar or other sweeteners. The stage of application of said coating is technically known as "pan coating", and the chewing gum thus obtained is called "panned chewing gum" "chewing gum dragee" or "pellet gum".

Numerous documents of the prior art relate to specific aspects of the sugar-coating process, and to products obtained from syrups of suitable compositions. See, for example, EP 1 ,481 ,597; WO 03/00068 and US 5,248,508.

Powder used in sugar-coating

The impalpable powder added to facilitate crystallisation and drying can consist of a plurality of single or mixed ingredients, or can be constituted by complex formulates.

In sugar-coating, the powder typically consists of milled sugar. In sugar-free coating, the powder can consist of the same sugar substitute as used for the syrup. For example, in maltitol coating, fine maltitol powder of high purity is used, as disclosed by EP 1 ,399,032.

In other cases, sprayed mixtures are used, such as Quick-coat Xylitol®, supplied by Alfred L. Wolff GmbH, Germany, which consists of xylitol and gum arabic.

In other cases solid mixtures are used; for example, IT MI20051005 teaches the use of mixtures of acidifiers, sugar substitutes and anti-caking agents, while US 5,882,707 discloses solid mixtures of carbohydrates, colorants and plasticisers. Coating powders are usually hygroscopic, because typically comprising water soluble sugars, polyols, hydrocolloids (like gum arabic or maltodextrin), alone or in combination thereof and, at the same time, being characterized by the high surface to weight ratio of the fine powders.

Any type of powder can be added, however, even with different purposes; for example, in US 2,304,246, activated carbon powder is added.

Apparatuses for sugar-coating and recycling of coating powder

Apparatuses for the production of coatings are also known. In recent technology, the essential element of these machines, called coating pans or coating machines in technical jargon, is a cylinder or a polyhedron, called the drum, installed with its axis laying orizonthally. The cylinder is equipped with devices to put it in rotation and is referred as "rotatable drum". Said cylinder can also present a plurality of holes designed for the introduction and extraction of air (perforated drum). The cores are loaded into the drum, which is made to rotate during coating operations. The interior of the cylinder is fitted with one or more nozzles for the application of the syrup while delivery and suction outlets for the drying air may be inside or outside the drum (in this case a perforated drum is used). The powder can be applied manually, but in machines of more recent construction the powder is applied with automatic pneumatic, mechanical or combined batching systems.

Examples of the prior art relating to the construction of coating pans are

US 4,586,457, GB 2,249,977 and WO 84/03610. In all these documents, particular importance is placed on the incoming and outgoing air with the aim of maximising the yield of the machinery, but the problem of powder recovery is not considered.

Equally, machinery for recovering powder from air and even recycling powder are known, but are applied to powders, apparatuses and processes substantially different from those to which the present invention relates.

WO 03/028618 describes, among other things, machinery for the production of tablets by compression of powdered material. Suction systems designed to clean the tablet punches of powder residues are fitted to these machines; the aspirated air can be passed through cyclones to recover these powder. The recycled powder has the same composition and granulometry of the fresh powder.

US 2007/0272598 teaches the use of cyclones for recycling powder generated by friction during the stages of transport of plastic granules. The powder extracted by an airstream is collected discontinuously in bins.

US 2007/272598 discloses the use of cyclones to remove contaminants from a flow of particulate material by a stream of air and dispose them in collection devices.

US 6, 129,946 teaches the use of powder mass sensors to meter the quantities of recycled and fresh powder in powder coating apparatuses. The mentioned powder coating apparatuses are not meant to use syrup or to coat food items and the recovered powder has the same composition as the fresh powder.

WO 2008/093190; US 6,080,217; US 5,739,429 describe powder recycling apparatuses to be used in spray coating techniques. In all the documents, food coating is not disclosed. Apparatuses are not conceived as coupled to pan coating of food products which poses peculiar problems and in which recovered powder is different not only in granulometry, but also in composition from the freshly purchased powder. Recycling of hygroscopic powder, like the one used in pan coating of food products is also not disclosed in the cited documents.

Technical problem

The use of powder increases the speed of the pan coating process, which is one of the most time consuming processes in the confectionery field. There is consequently an interest in and a trend towards increasing use of powder. The use of automatic powder diffusion systems for large pan coating machines promoted this trend. The presence of large amounts of cores in modern machines increases the friction between them during pan coating, and controls the roughness caused by the use of excessive amounts of powder. At the same time, however, the friction between the partly coated cores during drying produces more powder.

Due to the excess powder applied to the wet syrup and to the powder generated by the friction between the rotating cores, the suction air draws with it in suspension powder with a more complex composition than the fresh powder introduced according to the prior art, because it also contains components of sugar-coating syrup (flavourings, colouring, intensive sweeteners, etc.).

Said powder, termed "second powder", comprises sugars, polyols, binders, anti-caking agents possibly present in the first powder and different polyols, different binders, flavours, colours, sweeteners and other additives or ingredients present in the coating syrup or in the centre to be coated.

The second powder cannot be vented into the atmosphere due to pollution problems. Traditionally, the air is filtered and the filters cleaned at the intervals required to maintain their efficiency.

Second powder collected in this way cannot be recycled in a modern factory, wherein the same coating apparatus is used to produce products with different flavourings and colouring and different main ingredients (sugar, xylitol, isomalt, maltitol, etc.) in sequence, so the second powder recovered by the filters is in a heterogeneous mixture, and its composition is always different over time.

Moreover, the applicant has found that the second powder has a different particle-size distribution from the originally purchased "fresh powder" introduced into the drum of the coating pan. In particular, said second powder is enriched with fractions having a larger particle size than the starting fresh powder. The use of this second powder would consequently cause quality problems with the appearance of the product, because the coarser particles appear as irregularities ("pimples" in jargon) on the smooth surface of the candy.

Furthermore the second powder should be more sticky and prone to caking than the fresh powder because it is an hygroscopic powder coming from a wet environment, i.e. the wet rotating drum with wet centres covered with a coating syrup which is not yet dried. Its continuous recycling is counterintuitive in that a man skilled in the art could easily anticipate clogging problems in the pipes and distributing system of the recycled second powder.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art.

In particular, one purpose of the invention is to provide a method for coating edible products, able to recycle the powder present in the pan coating air (second powder) efficiently, with financial advantages (less fresh powder to be purchased) and logistical benefits (no storage or disposal).

A further purpose of the invention is to provide a method which achieves the results described above, but at the same time does not reduce the quality of the finished sugar-coated product.

Another purpose of the invention is to build an apparatus for the implementation of said method on an industrial scale, which is simple and cheap to manufacture.

Description

Said aims are achieved, according to the invention, with the characteristics of the annexed independent claims.

Advantageous embodiments of the invention are described in the dependent claims.

Description of method

The method for coating edible products according to the invention involves the recovery of the pan-coating second powder present in the air aspirated from the coating-pan drum, and its reintroduction into the pan-coating drum in subsequent powder application stages during the completion of pan-coating.

According to a preferred aspect of the present invention, after recovery from the air, the method also involves continuous sieving of the second powder and discarding of powder with a particle size greater than that desired, while second powder fraction of the desired particle size is sent to the coating- pan drum.

The recycled second powder is usually insufficient to provide the total quantity of powder which needs to be introduced into the drum at each stage of use. The missing part of that total quantity consists of fresh powder, which added to with the recycled second powder. A preferred form of embodiment of the present invention includes a stage at which recycled second and fresh purchased powder are combined to form the total quantity required before reintroduction into the drum.

In a different embodiment, the applicant has surprisingly found that, despite the different composition, granulometry and water content, the recycled second powder and fresh powder can be applied sequentially, one after the other, in the drum, until the total quantity is reached, without any union or premixing stage between the two. If the total quantity of powder required in a certain powder application stage is sufficiently low to be fulfilled by the recycled second powder, then all the applied powder at that stage can be constituted by recycled second powder. This is in contrast to the prior art focusing on the control of the ratio between fresh and recycled powder.

The present invention also relates to a method of diverting the powder to a collection point before introduction into the drum. Said method is used when necessary, for example on change of product or washing, to empty the recycling line. Said method preferentially involves discontinuous collection in small food-grade containers, so that second powder originating from pan- coating of different products are not mixed. The second powder thus discontinuously recovered (a very small fraction of the total powder recovered continuously) can be reused when coating of the same type of product resumes.

In a preferred embodiment of the present invention, the method of second powder continuous recycling is applied simultaneously with methods which involve treating the air introduced into the drum, and allow the air temperature, relative humidity and air quantity to be controlled.

The control of these parameters can be effected with known means and apparatuses. Quantity of air can not be determined in absolute numbers but must be correlated to the dimensions and shape of the coating drum.

The applicant has found that, by controlling the mentioned parameters, the second powder does not clog the pipelines and does not clog in the recovery apparatus.

Description of apparatus

The air with the second powder, aspirated from the rotatable drum of the coating pan is introduced into one or more devices for continuous extraction of the powder. Said devices comprise, for example, continuous filters, cyclones and the like.

Similar devices include drum filters fitted with continuous suction devices similar to those marketed by the Osprey Corporation and described in US 5,679, 136, which, however, must be adapted to non-fibrous particulate matter. Alternatively, cassette filters fitted with a continuous cleaning system using a counterflow of air (Dantherm filtration), or polygonal filters cleaned electromechanically on a continuous or semi-continuous basis, can be used. However, these filters have the drawback of retaining the powder on surfaces which cannot be 100% cleaned continuously, with the result that different second powders, derived from different coating fresh powder and syrups, contaminate one another. Moreover, the creation of compact layers of powder means that aggregates build up, so the difference between the particle size of the fresh powder and the recycled second powder increases.

In a preferred embodiment of the present invention, the devices are one or more cyclones which can be configured in series or in parallel. Their number and size depend on the amount of the outgoing airflow (suction) from the coating-pan drum and the suction power downstream of it, and on the desired efficiency of second powder separation from air.

Said cyclones are fitted with continuous or semi-continuous outlets for the powder that collects in the cone. Said outlet means are known to one skilled in the art, and allow discharge of the product without placing the base of the cyclone cone in communication with the environment. The applicant has found that cyclones do not compact the second powder, and minimise contamination between second powder of different compositions which are separated at different times, because they do not have absorbent parts. It is also possible to make the cyclones entirely of steel, thus allowing cleaning with water if necessary.

The outgoing air from the cyclones is conveyed to a suction pump, and can be filtered before emission into the atmosphere, as the process of elimination through cyclones can still leave a fraction of particularly fine dust in the air.

The second powder recovered from the air can be advantageously sent to continuous sieving machines that reject excessively coarse particle sizes.

The second powder, preferably the fine second powder output from the sieving machine, is conveyed continuously and reintroduced into the coating-pan drum during successive repetitions of the stage of powder application of the same pan-coating process.

The second powder recovered downstream of the cyclone towards the coating-pan drum can be conveyed by any means designed for the purpose, including conveyor belts, bucket elevators, screws and the like. A particularly preferred method is pneumatic conveyance, which will be described in the detailed description in the next few paragraphs. The technical expert will note that whatever the embodiment, for the purpose of the present invention the conveyor system must minimise the time between recovery of the powder and its reintroduction into the drum.

In this way the recycled second powder is applied to the product with which it has been in contact and from which it originated, in the case of excess powder which was not anchored or partially anchored to the cores and was removed by the airstream, or powder originating from friction between the building coating of the cores or between the cores and the walls of the rotating drum during air drying. In any case the recycled second powder does not have the same composition as the fresh powder, being contaminated from all the other ingredients present in the coating, some of which vary considerably between products.

Ingredients typically part of the second powder which are absent in the fresh powder are: food colours (like natural, artificial, colouring foodstuff), flavours (like peppermint, spearmint, fruit, strawberry, vanilla and the like). The fresh powder can be devoid of binders, while the second powder is usually contaminated by the binders present in the coating syrup. The binders are usually hydrocolloids like gum arabic, gum talha, maltodextrin, gelatin alone or in combination thereof. The fresh powder usually comprise one sugar or sugar alcohol (e.g. one of sucrose, xylitol, isomalt, maltitol, mannitol, sorbitol), the second powder may be contaminated with one or more sugar or sugar alcohol, different from the one originally contained in the fresh powder and derived from the core or from the coating syrup. The fresh powder is usually dry, the second powder comes from a moist environment, because the fresh powder is spread onto the centres when they are wet with the coating syrup, which contains water. A a consequence, the second powder might carry more water than the first powder. The presence or prevision of increased water content together with hydrosoluble and hydrophilic components like the mentioned sugars and polyols, further to hydrocolloids makes the use of second powder counterintuitive, because problems of clogging or soiling or caking of parts of the recovery apparatus might be easily anticipated, as well as problems of distribution using automated powder distribution apparatuses.

Recycling the second powder on the same growing coating of the cores during the repetition of powder application in the same coating process (stage b) is, therefore, the only way of preventing contamination between products, while maintaining a constant composition of the coated product.

The applicant has surprisingly found that using the apparatus of the present invention no problem of clogging or soiling or caking of the second powder occurs in parts of the recovery apparatus. No problem of distribution using automated powder distribution apparatuses has been experienced.

Fresh powder may be added to the recovered second powder to provide the total quantity of powder needed for coating. The powders can be combined in a loading hopper into which recycled second powder and fresh powder are introduced, but not necessarily mixed. Said combination of fresh powder and recycled second powder can then be applied in the coating-pan drum by any method (see description below), including manual batching with the traditional scoops, although it is preferable to employ an automatic apparatus that uses a flow of compressed air to convey the powders from the powder batching hopper to the rotating drum, and a shaft batcher with a plurality of nozzles to ensure uniform distribution of the combined powders along the whole length of the coating-pan drum.

Alternatively, the powders can be combined directly in the coating pan, applying measured amounts of recycled second powder and fresh powder in succession via an apparatus consisting of:

a) a pneumatic batching unit, which takes up the recycled second powder from a hopper on a load cell, measures by weight difference the amount of recycled second powder introduced in real time, and communicates the amount remaining to the next part b); b) a second pneumatic batching unit for fresh powder, which takes up the fresh powder from a second hopper on a load cell, and monitors the amount of fresh powder added to the drum until the desired total weight of combined powders is reached.

At some particular stages it may be necessary to eliminate the powder present in the recycling apparatus without necessarily introducing it into the coating-pan rotatable drum. These stages coincide with washing or changes of product. For this purpose, the apparatus claimed in the present invention optionally includes recycled powder diversion points upstream of the coating- pan rotatable drum. Said diversion can consist simply of a diverter valve upstream of the cyclones described above, which diverts the air with the second powder still in suspension towards a suction pump fitted with filters that prevent it from being emitted into the atmosphere. Alternatively, said diversion can consist of a diverter gate valve downstream of the cyclone that directs the powder discontinuously towards a collection point. Alternatively, said diversion can consist of suction of the powder downstream of said cyclones, which conveys the powder to a cyclone that discharges it discontinuously without reintroducing the powder into the drum.

Further characteristics of the invention will appear more clearly from the detailed description of the preferred embodiments that follows, illustrated in the single annexed drawing, which is a schematic drawing of a pan-coating integrated with a recycling apparatus according to the invention.

Detailed description of a preferred embodiment of the invention

The drawing in annexed figure 1 shows different rectangles drawn to indicate the various units of the apparatus according to the invention.

In particular, rectangle C generically indicates the coating-pan unit, rectangle B indicates an air treatment unit before air introduction into the coating pan, rectangle D is a final filtration unit for the aspirated air, rectangle A is the powder recycling unit according to the invention, and finally, rectangle Al enclosed in rectangle A is the powder launch unit.

In the annexed figure, number 1 generically indicates a coating pan which is known in itself, and therefore not further described, for coating of edible products. In the present case, coating pan 1 is fitted with a cylindrical rotatable drum 30 which is caused to rotate around its own horizontal axis, but this is not mandatory for the purpose of the present invention, in that coating pan 1 can have any other known configuration.

Cores 31 of the product to be coated are loaded into drum 30, which in coating pans of more modern design has a perforated mantle. Cores to be coated lie on the lower part of the drum forming a "bed" of cores, when the drum is rotating the bed is skewed/biased toward the direction of rotation and the centres are continuously tumbled one over the other. Drum 30 is equipped internally, according to known technology, with nozzles for the application of the syrup, which are usually fitted to a shaft lying approximately on the drum axis The drum has and delivery inlets and suction outlets for the drying air, indicated by arrows Fl and F2 respectively. In particular, a pump 2, for sending air to coating pan 1 in the direction of arrow Fl , is necessary.

In a preferred form of embodiment, air Fl is generated by a unit, represented by rectangle B, designed to control its temperature, humidity, quantity as well as purity from oil droplets, dust or other contaminants which may spoil the food product quality. The temperature of the incoming air is varied to optimise drying at the various coating stages, and can range, for example, from 15°C to 35°C. Humidity is maintained at low levels (such as 2 g/kg). The applicant has found that, by maintaining adequate incoming air (Fl) conditions, like temperature from 15°C to 35°C and humidity lower than 4 g/kg, the powder in the outgoing air (F2) continues to flow freely, although it mainly consists of hygroscopic compounds such as hydrocolloids and polyalcohols, and although the air carries with it all the humidity evaporated from the bed of wet cores into the rotating drum (30) through which it passes.

The first powder can be introduced into cylindrical chamber 30 in any way, the annexed figure reports an arrow F3 for the introduction thereof, as will be described in more detail below.

The air mixed with the second powder aspirated from rotating drum 30 by a suction pump 4 is conveyed to a first cyclone 3, wherein the powder deposited on the base passes through a butterfly valve 5 and is collected in a container 6 from which, via a further butterfly valve 7, it is emitted into an airstream (arrow F4). When the butterfly valve 7 is closed, the butterfly valve 5 is opened, and when the butterfly valve 7 is opened, the butterfly valve 5 is closed. With this apparatus the cyclone is substantially continuously emptied, while being kept sealed toward the environment and thus continuously operating.

The air stream F4passes through a filter 8, and is sent to a rotating sieve

9 which discards the coarse powder, collecting it in a container 10. Said rejected coarse powder typically has a particle size greater than 1000 μ, preferably greater than 400 μ, and even more preferably greater than 100 μ.

In a further preferred embodiment of the invention, the sieve operates through continuously rotating meshes and is designed to work in a pneumatic system with closed flow. In particular the sieve receives the flux F4 with the recovered second powder through a pipe connected through an air tight flange; the body of the sieve, housing the rotating meshes is also airtight; a first air proof outlet is connected to a pipe that redirects the flux F4 containing the sieved second powder toward a further cyclone; a second air proof outlet is connected to the container 10 receiving the rejected coarse powder. The preferred sieve operates continuously while assuring the high hygiene required by food application. The sieved part of the second powder, which has particle size lower than 1000 μ, preferably lower than 400 μ, and even more preferably lower than 100 μ, together with the air carrying it, is aspirated by a pump 13 and conveyed to a second cyclone 1 1 with incorporated filter. From cyclone 1 1 , the second powder with the desired particle size passes through a butterfly valve 12 and a diverter gate valve 14, to be sent alternatively to 16 or into one or more waste powder containers 15, whenever there is a change of product under processing. Containers 15 are preferably food-grade containers, and can be stored to reuse the second powder in the first compatible coating process.

Hopper 16 has the possibility to reintegrate the second powder with fresh powder and acts as a small powder reservoir for the following powder batching apparatus.

Alternatively, air flow F4 can originate not from filter 8, but from a vent in the wall of the conical portion of cyclone 3, a vent in air blowing pipeline F l , a vent in air suction pipeline F2, or combinations thereof. As will be evident to the skilled person, the three methods of supplying airstream F4 require a different balance of the suction power of pump 13. However, the origin of flow F4 in cyclone 3 or in the pipes of Fl or F2 has the advantage of maintaining the second powder in a air flow at controlled temperature and humidity.

Arrow F5 directed towards hopper 16 indicates the possible supplementation of fresh powder to the recovered second powder. In this preferred embodiment, the method of conveying the recovered second powder from cyclone 3 to the hopper 16 consists in pneumatic transport, and is preferred for speed and hygiene, because it can be built as a closed system preventing contact of the recycled second powder with the environment and its contaminants.

The recycled second powder present in hopper 16, possibly combined with fresh powder, is introduced into a powder batching hopper 18, as indicated by arrow F6, and sent to coating pan 1 via an ejector 19 and a compressor 20, following the path of arrow F3 previously introduced. The recycled second powder, possibly combined with fresh powder, is applied to product 31 through a distribution shaft fitted with suitable nozzles in such a way that the powder is evenly distributed along the whole length of drum 30.

The aspirated second powder is then recycled continuously and reintroduced into drum 30 in real time, in the immediately following pan-coating stages, while coarser powder is discharged to reject container 10. At each change of product, the recovered second powder is discharged into container 15.

A series of tables containing examples 1 to 21 follows.

Table I shows examples 1 to 7 of powder which can be used at the engrossing step.

TABLE I

Powder usable for coating (%)

Powder Powder Powder Powder Powder Powder Powder

Ingredient example example example example example example example

1 2 3 4 5 6 7

Milled sugar 20 79

Rice starch 80

Impalpable

100 39

isomalt powder

Xylitol on gum

arabic,

100 64

impalpable

powder

Maltitol

impalpable 100

powder

Gum arabic

60 35 20 powder

Anti-caking

1 1 1 agent Table II shows examples 8 to 12 of syrups which can be used at the engrossing step.

TABLE II

Engrossing syrups usable in coating (%)

Syrup Syrup Syrup Syrup Syrup

Ingredient

example 8 example 9 example 10 example 11 example 12

Sugar 39,5

Isomalt 65 - - -

Xylitol - 75 - -

Maltitol - - 64 -

Sorbitol - - - 73

Water 28 19 24,29 40 23

Gum arabic 1 5 10 20

Titanium dioxide 5 - 1 3

Allura red - 0,001 0,01 -

Mint flavouring 0,5

Orange

1 - - - flavouring

Strawberry

- 0,999 - - flavouring

Mango/peach

- - 0,7 - flavouring

Tutti Frutti

- - - 1 flavouring

Aspartame

0,02 0,015 0,03 0,01

(% excess weight) Table III contains examples 13 to 17 of syrups which can be used at the smoothing step.

TABLE III

Smoothing syrups usable in coating (%)

Syrup Syrup Syrup Syrup Syrup

Ingredient example example example example example

13 14 15 16 17

Sugar 70

Isomalt 60 - - -

Xylitol - 65 - -

Maltitol - - 64 -

Sorbitol - - - 63

Water 35 32.999 30 30 32

Gum arabic 0 2 4,99 0

Titanium

5 - 1 5 dioxide

Allura red - 0,001 0,01 -

Table IV shows, with examples 18 to 21 , a comparison between sugar- coating compositions with powder recycling according to the invention (examples 18 and 20) and conventional sugar-coating compositions without recycling (examples 19 and 21), indicating the saving on the purchase of fresh new powder. TABLE IV

Coating composition - % of dry matter

Example 19 Example 21

Example 18 Example 20

Ingredient (non- (non- (inventive) (inventive)

inventive) inventive)

40 40 60 60 bulking syrup

example 10 example 10 example 9 example 9

25 25 25 25 smoothing syrup

example 15 example 15 example 14 example 14 fresh powder 20 35 8 15 purchased example 3 example 3 example 2 example 2 recycled second

15 7

powder

< 0.1% < 0.1% < 0.1% < 0.1% other coatings (polishing (polishing (polishing (polishing wax) wax) wax) wax)

% saving on purchase of fresh powder

Example 21

Example 18 Example 19 Example 20

(non- (inventive) (non-inventive) (inventive)

inventive)

- 43% 0 - 47% 0

The advantages of the invention clearly appear from the details set out above: it allows continuous recycling of pan-coating second powder and consequently a financial saving in the use of the pan-coating unit, as well as a lower environmental impact.

Although the preceding description mainly referred to hard coating, the method and apparatus according to the invention can be used to coat any edible product, not necessarily to form a hard crust.

The invention is obviously not limited to the particular embodiment previously described and illustrated in the annexed drawing; numerous modifications of detail can be made which are within the reach of the skilled person (for example, additional compressed air outlets for washing, visual warnings, automatic control systems), while still remaining in the ambit of the innovation, as defined in the annexed claims.