EP1103467A1

EP1103467A1 - Method and apparatus for packaging crystalline fat-containing products

Info

Publication number: EP1103467A1
Application number: EP00204205A
Authority: EP
Inventors: Johannes Van Pijkeren
Original assignee: Friesland Brands BV
Current assignee: FrieslandCampina Nederland BV
Priority date: 1999-11-29
Filing date: 2000-11-27
Publication date: 2001-05-30
Also published as: NL1013694C2

Abstract

The invention relates to a method for packaging a product which is plastic in the preparation, wherein this plastic product is packaged in amounts of 2-50 kg, preferably of 5-25 kg, in a foil which at least consists of a heat-sealable material and which foil is applied around the product to be packaged, so that the foil completely encloses the product, and which foil is thereafter sealed using heat, whereafter the packaged product is cooled and stored in a conventional manner. The invention also relates to a packaged product and packaging apparatus.

Description

This invention relates to a method for packaging crystalline fat-containing products and essentially foods, as well as thus packaged products, and a packaging apparatus to be used therein. In particular, the invention relates to a packaging method for fat-containing products in bulk packages, for instance intended for sale to the professional large consumer, specifically in the catering industry, the bakery industry, and other food processing industries. Usually, a bulk package in these sectors is understood to refer to packaged units of a weight between 2 and 50 kg, and preferably between 5 and 25 kg.
The fat-containing products to which the invention is directed are fat-rich foods in which the fat fraction is the characteristic component and determines the dominant properties. Often, the fat fraction consists of fats which are wholly or partially solid at temperatures below 45°C and preferably below 40°C, so that at room temperature the product as a whole is substantially solid or thick-viscous, but in the production has the form of a plastic mass. Examples of such products are butter, margarine, chocolate and chocolate products, and all kinds of pastes.
The most well-known and common package for such fat-containing products, such as butter, margarine or chocolate products, for bulk consumption is a cardboard box, for instance a cardboard box having dimensions of, for instance, 30x40x25 cm, in which, for instance, 25 kg of butter can be packaged. A characteristic packaging process, such as that of packaging butter in a bulk package, comprises the following steps. In a packaging line, a normally formed box is set up, which is open at the top. Pulled above the open box is a sheet of foil, such as a sheet of paper provided with a wax layer or a sheet from a suitable plastic material. Next, the foil is pressed into the box by means of the filling nozzle (which has a shape especially adapted for that purpose), whereafter, while simultaneously moving the filling nozzle up, the fat-containing product is metered into the box.
For this process to proceed properly, the consistency of the fat-containing food must be within pre-set and known limits, lest the supply of the product to the filling machine and the metering thereof into the boxes should lead to any malfunctions or other problems, while moreover, in the case of products like butter and chocolate, the homogeneity and the eventual processing properties of the product are also (partly) determined by that.
To that end, before being filled into any package, such fat-containing products which have the form of a plastic mass in the production, are, as a rule, cooled, preferably in a scraped heat exchanger, and subsequently passed through a rest tube. In other words, the fat-containing products are produced as hot mass, but before being filled into any package, this plastic mass is to be converted to a mass which can be molded in the packaging machine, be metered, and wrapped in the paper mentioned earlier, or the plastic film. Thereafter, the masses shaped, for instance, into blocks or slabs, are packaged in cardboard boxes, or stacked loosely on a pallet with a protective cardboard or plastic around and over them.
This current packaging method, in which the fat-containing foods are packaged in a foil in a cardboard box, has inherent disadvantages. Thus, relatively much packaging material is needed, the packaging material has a low heat conduction, additional operations are needed in unpacking, and hygienic risks may be involved, in particular contamination and decay on the surface of the food. Overcoming these disadvantages is what the invention contemplates, while maintaining the characteristic product structure and the properties of use of the fat-containing products for the processer and while maintaining the conventional method of preparation, in any case proceeding in line with the conventional manner of preparation.
More particularly, it is important that for the known applications of fat-containing foods in the industrial sectors indicated earlier, the product that is used in any application has the proper processing properties. Playing an essential role here are consistency, texture, strength, elasticity, viscosity and homogeneity of the product. In addition to, obviously, the product composition and the manner of preparation, the processing temperature and the storage conditions are highly important for such crystalline fat-containing products. Moreover, in bulk packages, also a constant post-treatment of the packaged product is necessary for a constant quality.
This problem is presently elaborated further with butter and chocolate as examples. These examples are not intended to be limiting; in fact, they hold in general for fat-containing foods which are produced on an industrial scale as plastic mass and in practice are offered as (halfhard) product in a non-hermetically closed package.
Traditionally prepared butter is subject to different decay possibilities. Upon storage at normal ambient temperature, as a result of the nature and composition of the product and of the conditions during preparation and packaging, a great risk of microbial spoilage will be present, especially also when in the preparation no preservatives are added (or may be added). It is known, for instance, that on the surface of butter fungi develop relatively fast. This is naturally undesired.
Therefore, butter in bulk packages is stored while cooled. Thus, butter can be stored, for instance, for 4-10 weeks at temperatures below 6°C, while for longer storage periods storage at -18°C is preferred. To enable subsequent processing, the product must be heated. This is often accompanied by condensation of moisture from the ambient air on the cold package and on the cold product, This is a serious problem in the food products of the subject type because this can give rise to (an) increased (chance of) fungoid growth.
Butter packaged in the above-described bulk package traverses in this bulk package a particular, slowly progressing cooling process, in order to give the packaged product particular processing properties, which are of use to the large consumer.
The prior art, in addition to disclosing the traditional manner of packaging utilizing the cardboard box with a foil therein, also discloses packages of butter consisting of a single wrap without outer package. That packaging method necessitates forced cooling of the freshly prepared product before packaging takes place. Naturally, when the packaging form does not provide any strength, the product itself must have a certain strength, if only to ensure stackability of the packaging units. In this mode, the advantageous gradual cooling process as mentioned in the preceding paragraph cannot be carried out.
It is also known that in certain cases the fat-containing product is packaged in a foil in an outer box, whereafter the outer box, after the normal and desired cooling process, is removed, to avoid the user having to remove the outer box. It is evident that in this case the above-mentioned heating process prior to processing imposes additional requirements on the handling of the blocks in foil, both in respect of the hygienic measures, because of the risks of contamination and condensation of moisture on the product, and with a view to the consistency of the product ready for processing, which loses a part of its own strength precisely because of the heating. In terms of process, this method is a variant of the normal packaging method for fat-containing products.
For chocolate products, of which chocolate couverture is an example, the storage temperature is extremely important. During storage, crystallized cocoa fat undergoes a reorientation, whereby the attractive appearance obtained directly after preparation changes due to a change of the crystal structure. These changes result in appearance deviations from the desired gloss and structure and are designated by terms such as fat bloom. For the further processing, a heating of the product is desired. To be able to realize this, the product, after unpacking, is heated in a pan until it melts, whereafter processing is possible. It will be clear that this method involves the risk of bacterial, or generally microbial, contamination.
Presently, the invention concerns the packaging of fat-containing products which are plastic during preparation, in a single-use packaging form which obviates the above-outlined disadvantages of the conventional package, it having been found, as a major advantage, that both the preparation and the cooling method and the heating method after storage can remain the same as for the known packaging method utilizing the cardboard box with a foil therein, while the associated heat transport proceeds more readily because of the absence of a cardboard wall (the outer box), which has a clearly insulating influence. This does not yield any danger of contamination of the food. Further, no adaptations in the manner of preparing the product to be packaged are required.
To that end, the invention relates to a method for packaging a product which is plastic during preparation, wherein this plastic product is packaged in amounts of 2-50 kg, preferably of 5-25 kg, in a foil which at least consists of a heat-sealable material and which foil is applied around the product to be packaged so as to enclose that product completely, and which foil is then sealed utilizing heat, whereafter the packaged product is stored while cooled, in the conventional manner.
As a rule, as is customary for conventional packaging forms, the packaged product is cooled to storage temperature by placing the bulk packages, after their being stacked on, for instance, a pallet, in a storage and refrigerated space with an ambient temperature current for the product. The cooling of this storage and refrigerated space occurs in a manner known in the industrial art. Depending on the intensity of cooling, the product stored in this space takes the temperature required for prolonged storage in a period from 2 to 5 days. Butter, for instance, traverses the following temperature scheme: in the preparation, butter is packaged as a plastic mass having a temperature of about 15°C and subsequently placed in a refrigerated space having a temperature lower than 6°C; for prolonged storage, it is required to cool to below -18°C. Chocolate is packaged at a temperature of about 26°C and cooled down to about 18°C.
In a preferred embodiment, the method for packaging a product which is plastic in the preparation is carried out utilizing a forming-filling-closing machine.
The thus manufactured packaging form has the advantage that it is hermetically closed and thus fully excludes the influence of outside air, thus enabling evidently safer work from a hygienic and microbial viewpoint. Moreover, the product cannot locally dry out, which would lead to a disturbance of the physical form.
A major additional advantage is that much less packaging material is needed, so that the packaging costs are lower and the amount of packaging waste is reduced. Also, the absence of a cardboard outer box safeguards the preparer as well as the user against the risk that bacterial contamination or ambient contamination still occur during packing and unpacking.
Incidentally, the prior art discloses methods of packaging butter intended for use by individual consumers in single-use packaging forms. Thus, U.S. Patent 4,648,506 discloses packaging consumer portions of butter in a kind of blister pack, the pack at the same time serving as spreading utensil. Clearly, the eye is here focused entirely on an application intended for the consumer when he wants to provide a sandwich or comparable product with an amount of butter appropriate therefor.
U.S. Patent 4,557,103 describes the packaging of butter in consumer units in foil with the aid of a forming-filling-closing apparatus, whereby the packaged product is cooled as fast as possible with the aid of liquid nitrogen in order to minimize the effects of the heat-sealing of the foil on the packaged product.
In the British patent specification, portions of product, such as cheese and the like, are packed between two layers of foil material which are applied onto each to enclose the portion of product, leaving a number of openings unsealed to allow gas introduced into the package along with air to escape. After this, in a second sealing process, the whole is hermetically closed.
From these publications it is not to be derived in any way that packaging fat-containing foods in a bulk package while maintaining the conventional cooling techniques gives advantages, in particular not because equipment for carrying out the method according to the present invention is not commercially available.
More particularly, the invention relates to the packaging of fat-containing products directly after production with the aid of a so-called forming-filling-closing machine in a hermetically closed plastic sachet, which, for the benefit of the user, is preferably provided with a so-called easy-opening provision. The sachet is formed from plastic film suitable therefor, which can consist of one or more components or layers, as prompted by the wish to create a lesser or higher degree of protection from air and/or light influences. The plastic film material is therefore essentially impervious to moisture and gases.
Incidentally, French patent specification 1,562,131 discloses a method for packaging small amounts of cheese product, and in particular the separate packaging of slices of cheese. In particular, an extrusible cheese product is packed warm in a tube of plastic, whereafter a transversal seal is applied at the top and bottom of the cheese slice. In contrast with the present invention, this does not concern a product which, at room temperature, in any case the temperature of use, contains a high percentage of fat that is solid. A fat-rich product containing a large amount of crystalline fat at room temperature does not, in large amounts, allow of hermetic packaging in the manner as described in the French patent specification mentioned, that is, by simply pressing out the ambient air and possibly product. In addition, according to the invention, no chain of packaging units is formed, since for such purpose the weight amounts per packaging unit are physically difficult to handle, if at all.
Heat-sealable plastic films suitable for use in the invention are known to those skilled in the art and can be selected, for instance, from food-compatible polymer films, such as polyethylene, copolymers of ethylene and other α-olefins, ethylene vinyl acetate polymers as well as mixtures of these polymers. Suitable in particular are commercially available films from ATTANE®, EXACT® and DOWLEX®.
The heat-sealable polymer films can be combined with a variety of types of barrier layers, for instance with films from polyester, nylon, ethylene vinyl alcohol, polyvinylidene dichloride and metallized films. Thus, preferably a material impervious to daylight and/or artificial light can be used.
In a preferred embodiment, the sealed package can be simply opened in that the seals can be pulled loose. In another preferred embodiment, a pouring opening which is easy to open is provided.
A packaging apparatus suitable for practicing the method according to the invention will be further elucidated on the basis of an exemplary embodiment represented in the drawing. In the drawing:
Fig. 1 shows a schematic representation of a packaging apparatus;
Fig. 2 is a section of a package directly after the formation thereof; and
Fig. 3 is a section of a package during storage.
The figures only concern a schematic representation of a preferred embodiment of the apparatus.
Fig. 1 shows a packaging apparatus designed as a forming-filling-closing machine, for packaging in film sachets portions of fat-containing product which is plastic in the preparation. The packaging apparatus comprises a supply line 1 for supplying the product to be packaged. The supply line 1 includes a pump 2 and a valve 3 located downstream thereof. The supply line 1 terminates in a filling pipe 4. The filling pipe 4 is surrounded by a forming collar 5 by which a strip of packaging foil 6 which is supplied from a roll 7 in a supply direction 8 can be guided around the filling pipe 4. The longitudinal edges 10A, 10B of the strip of packaging foil 6 are thereby placed onto each other by the forming collar 5 and connected with each other by means of a first heat-sealing device 9, yielding a tube 11 extending substantially coaxially with the filling pipe 4 and having a longitudinal seal 12 extending in longitudinal direction.
The packaging apparatus is further provided with a second heat-sealing device 13 with which the walls of the tube 11 can be joined together, so that a seal 14 extending in transverse direction of the tube can be provided.
The packaging apparatus is further provided with transport means (not shown) with which the strip of packaging foil 6 can be incrementally displaced in the foil supply direction 8 after the lower end of the tube 11 has been heat-sealed by means of the second heat-sealing device 13 to form a bag. The bag-shaped end is then filled, by way of the filling pipe 4, with a portion of product, for instance a portion 16 of 25 kg of product, by operating the pump 2 and/or the shutoff valve 3 by means of a control 15 to allow a portion 16 to flow from the supply line 1 to the filling pipe 4. With the aid of the supply line 1, the product can here be supplied directly after being manufactured, so that the product flows from the filling pipe 4 without special heat treatment or cooling step.
During the inflow of the portion 16 into the bag-shaped end of the tube 11, a gas, such as for instance carbon dioxide gas, can be supplied with the aid of a supply line 17, by means of which the ambient air present in the bag-shaped end of the tube 11 can be expelled. To that end, the supply line 17 can advantageously be arranged coaxially between the forming collar 5 and the filling pipe 4, so that the displacement gas can be supplied via the space between the filling pipe 4 and the supply line 17, and the ambient air can be discharged via the space between the supply line 17 and the forming collar 5.
After a portion of product 16 has been introduced into the bag-shaped end of the tube 11, and the ambient air has optionally been displaced with displacement gas, the second heat-sealing device 13 is operated through the control 15. A sachet 18 is thereby formed, in which a portion of product 16 is hermetically packaged. Simultaneously, with the seal 14, a new bag-shaped end is formed on the tube 11. After the strip of packaging foil 6 has been moved by the transport means in the foil supply direction 8 over a distance corresponding to the length of one sachet 18, the sachet 18 is separated from the tube 11 by cutting the seal 14 with the aid of a cutting device 19. Simultaneously, the pump and/or the shutoff valve is operated again by the control to release a portion 16.
Referring to Fig. 2, there is shown that directly after forming the package, a space 20 filled with gas is present between the portion of product 16 and the foil wall 21 of the sachet 18. When the space 20 is filled with a gas which can be absorbed or otherwise taken up at least partly, but preferably completely, by the portion of product 16, what is achieved is that the space 20 filled with gas can shrink in the course of time and that the foil wall 20 can cling tightly, at any rate more tightly, to the portion 16. This is represented in Fig. 3.
It is noted that the packaging apparatus may also be designed in different ways. Thus, the second heat-sealing device 13 may be of twin design, or with a single heat-sealing device 13 two transverse seals extending at a mutual interspace may be provided, which are cut loose by means of the cutting device 19. Further, the heat-sealing device 13 may be reciprocated in the supply direction 8 to take care of the transport of the sachets and/or the strip of foil 6. Further, advantageously, supporting means may be provided for supporting the package (to be formed) 18. To that end, advantageously, the longitudinal axis of the filling pipe 4 and the forming collar can be arranged substantially horizontally, or at least partly horizontally, so that the sachets 18 can be formed in a lying orientation and during forming can be supported to reduce the tensile strain on the strip of foil.
Such variations are understood to fall within the scope of the invention as set forth in the claims.
In a particular embodiment, as described, the air left in the sachet formed is displaced by a non-oxidative gas, preferably of a composition such that this gas is largely taken up by the fat phase present, so that the package practically becomes a vacuum-pack form, which provides additional protection from oxidation and possible growth of microorganisms at the interface of product and air.
Thus, in a preferred embodiment of the method according to the invention, for the purpose of completely closing the foil, air which, along with the product to be packaged, is enclosed by the foil is displaced by a non-oxidative gas. The non-oxidative gas then preferably has a composition such that it is largely taken up into the fat phase present. It is preferred that the non-oxidative gas consists for at least 75%, and preferably completely, of carbon dioxide. Thus, it has been found that butter can take up carbon dioxide in an amount corresponding to the volume of the butter.
For butter, it has been found that when CO₂ is introduced into the foil, the number of germs, in particular of fungi, per gram of butter is less than 10 after 4 weeks' storage at 20°C, while this number is more than 100 germs per gram of product for butter packaged without displacement of gas. Thus the invention makes it possible to reduce the risk of fungoid growth to the extent where butter can be stored at least one to two weeks - in a closed package - at a temperature of 12-18°C, which is an overt advantage.
The dimensioning of the heat-sealed foil, i.e. the sachet, is chosen such that the filled packaging units can be stacked on a pallet in interlocking patterns, so that the absence of an inherent structure due to the still relatively soft consistency of the freshly packed product does not present any problem in stacking.
If desired in the distribution and/or sale, the sachet-packed units can still be provided, per pallet, with a protective sleeve of a material suitable therefor. To be considered here is, for instance, an envelope from corrugated board.
Presently, the invention will be further described in and by the following, non-limiting examples.

Example 1

In the above-described forming-filling-sealing machine, 2 kg of butter was brought onto a polyethylene film having dimensions of 36x40 cm. The butter was enclosed by the film, leaving a beam-shaped piece of butter in a polyethylene sachet. This packed product was found to be properly stackable and, after a conventional manner of cooling and after 14 days' storage while cooled at 6°C and subsequent reheating to processing temperature, possessed the normal properties desired by the processer. This meant that the strength of this product was identical to that of the same product when packed in the conventional package, i.e., wrapped in polyethylene film in cardboard outer box. Also with regard to other product characteristics, such as taste, deformability, elasticity and moisture distribution, no deviations in comparison with the traditionally packed butter were observed.

Example 2

In the above-described forming-filling-sealing machine, 15 kg of couverture chocolate was brought onto a polyethylene film having dimensions of 84x38 cm. The chocolate was enclosed by the film, leaving a block-shaped portion of chocolate in polyethylene sachet. It was found that - using a water bath - this product could be heated in the package to the processing temperature. By perforating the package at a specific point priorly provided for that purpose, use of the product was possible without it needing to be exposed prematurely to the environment.

Claims

A method for packaging a product which is plastic in the preparation, wherein this plastic product is packaged in amounts of 2-50 kg, preferably of 5-25 kg, in a foil which at least consists of a heat-sealable material and which foil is applied around the product to be packaged, so that the foil completely encloses the product, and which foil is thereafter sealed using heat, whereafter the packaged product is cooled and stored in a conventional manner.
A method according to claim 1, wherein the packaging step is carried out using a forming-filling-closing machine.
A method according to any one of the preceding claims, wherein, for the purpose of the complete closure of the foil, air which, along with the product to be packaged, is enclosed by the foil is displaced by a non-oxidative gas.
A method according to claim 3, wherein the non-oxidative gas is of a composition such that it is largely taken up by the fat phase present.
A method according to claim 3 or 4, wherein the non-oxidative gas consists for at least 75%, and preferably completely, of carbon dioxide.
A method according to any one of the preceding claims, wherein a foil is used with at least one of the foil layers being impervious to daylight and/or artificial light.
A method according to any one of the preceding claims, wherein the closed foil is provided with an 'easy opening' provision.
A method according to any one of the preceding claims, wherein the product to be packaged is butter.
An apparatus for packaging portions of crystalline fat-containing plastic product in foil sachets, comprising at least one filling pipe with which in each case a portion of product can be dispensed from a supply, a forming collar arranged around the filling pipe, for transforming a strip of packaging foil around the filling pipe into a tube, and heat-sealing means for heat-sealing, with inclusion of a portion of product, the tube of packaging foil to form a sachet.
An apparatus according to claim 9, wherein the filling pipe and the forming collar are arranged substantially coaxially.
An apparatus according to claim 9 or 10, wherein the longitudinal axes of the filling pipe and the forming collar extend substantially horizontally.
An apparatus according to any one of claims 9-11, wherein supply means are provided for supplying a displacement gas, which supply means are arranged in an interspace formed between the filling pipe and the forming collar.
A crystalline fat-containing product, packaged in foil with the aid of the method or apparatus according to any one of the preceding claims.