Process for labelling food products having uneven and/or greasy outer surfaces

Description

[0001] The present invention relates to a process for labelling food products, and more particularly a process providing the use of oozing tissue paper labels stuck by means of an animal gelatin.

[0002] It is known that several food products, especially dressed pork products and cheeses, are indelibly marked to guarantee their authenticity or origin. To this purpose, one of the most common methods is branding, which however does not allow the impression on the product of detailed information, rather just very simple characters and/or symbols. Other methods, such as the application of labels or bands, either made of paper or plastic, are applied with difficulty to those products which often have a greasy surface from which said labels are easily removable, even accidentally.

[0003] These problems have already been dealt with in patent application n.MI92A001130 in the name of the same applicant. This application discloses a process for labelling food products characterized by applying a label provided underneath with a layer of adhesive substance which, upon heating, is suitable to penetrate into the product surface, thus forming a permanent binding with the product after cooling. These process allows the impression on the product of a lot of detailed information, as well as the use of elaborate and/or colour marks difficult to be counterfeited. Although it has these advantages, the above process still has some drawbacks. First of all, applying said type of label requires the use of a heated piston, which needs an even surface in order to contact uniformly the adhesive to be heated, and however causes a local heating of the product. Moreover, the adhesive has to be previously applied on the label. Said adhesive may also have some problems of penetration into particularly impermeable surfaces.

[0004] Therefore, the object of the present invention is to provide a process for labelling food products which, in addition to having the advantages of the process of the above-cited prior patent, also overcomes the drawbacks still pending.

[0005] This object is achieved by means of a process having the characteristics cited in the characterizing part of claim 1.

[0006] This process has a first significant advantage in that the label can be applied without difficulty also to uneven and/or particularly impermeable surfaces. Furthermore, a precise positioning of the product with respect to the labelling plant, as in the previous case, is not required.

[0007] A second advantage stems from the fact that the adhesive is not previously applied on the label, but just on the product itself upon labelling, with a subsequent reduction of the cost for preparing the labels.

[0008] A further advantage of the present process is given by the fact that it can be employed even on particularly heat-sensible products, since the adhesive being used is heated only before its application on the product and only at a temperature slightly above room temperature (about 40°C).

[0009] These and other advantages and characteristics of the process according to the present invention will be apparent from the following detailed description of a preferred embodiment thereof reported as a non-limiting example.

[0010] Consider a food product having a surface of uneven profile, such as, for example, a so-called "furrowed" cheese. A first layer of adhesive for alimentary use, which is fluid enough to be sprayed on the product by means of a nozzle, is applied on said surface. Straight after, before the adhesive dries up, a label is placed thereon. This label is made of oozing tissue paper, i.e. a very porous and light paper, densely covered with micro holes. The weight in grams of said type of paper is lower than 30 gr/m², preferably 19 gr/m². Thanks to these characteristics, the label becomes soaked with adhesive and is practically incorporated into the adhesive layer previously applied and not yet dried. Finally, the label is covered with a further layer of adhesive to assure its total adhesion and incorporation.

[0011] Through the above process, applying the label is much easier and faster, as well as possible on any kind of product. However, it is clear that a previous degreasing of the surface can increase the adhesion of the first layer of adhesive sprayed on the product.

[0012] The researches and tests carried out by the applicant have shown that the most suitable adhesive for alimentary use for the accomplishment of the process according to the present invention is animal gelatin. It is known that said gelatin is the product of partial hydrolysis of the collagen contained in the skin and bones of animals, and differs from animal glue due to its greater purity, to the extent of being edible. This characteristic of the adhesive is strictly indispensable, in that it is usually applied on surfaces, such as the skin of dressed pork products or cheese-rinds, which may afterwards even be eaten. Moreover, from the hygienic point of view, gelatin offers the greatest safety to the consumer and in this regard can not be replaced by animal glue.

[0013] The main types of animal gelatin presently on the market are those coming from pigskin through acid process, from cowskin through alkaline process, and from bones through acid or alkaline process. The adhesive used in the process according to the present invention is preferably obtained from a gelatin coming from skin, and more preferably from gelatin coming from pigskin. In order to prepare the adhesive to be sprayed on the product to be labelled, it is sufficient to dissolve said gelatin in water heated at a temperature included between 30°C and 50°C, preferably about 40°C. A temperature equal or just lower than that is also maintained in the spraying apparatus to prevent the gelatin from starting to harden thereby causing the clogging of the nozzle. The amount of gelatin to be dissolved in water is preferably about 5% on a weight basis, while keeping in mind that higher percentages result in an adhesive which, once dried, tends to form a continuous film easily detachable from the surface on which it is applied. This type of adhesive is already very sticky in the liquid or semi-drying phase, and even when the drying is over it remains resilient and flexible, not becoming friable. Moreover, it can be easily coloured by means of food dyes.

[0014] In order to assure an adequate adhesion of the label to the product, the gelatin employed preferably has a strength between 220 and 280 Bloom degrees. The solvent used in the preparation of the adhesive is preferably water additivated with an antibacterial agent, such as potassium sorbate at 0,4%, and possibly a pH corrector, such as citric acid, to take the pH to 5-5.5 so as to make the antibacterial action more effective. Alternatively, a mixture of water and alimentary grade 99° ethanol, upto a proportion of 50% by volume, can be used. In this case, the gelatin dries up more quickly and no other correctors or additives are required. However, this involves a higher cost and heavier fulfilments of bureaucratic nature for the use of ethanol.

[0015] Another additive advisable for the cases in which the adhesive is applied by spraying is an anti-foaming agent preventing the formation of bubbles which stick to the label and, upon drying, make the surface thereof rough. Anti-foaming agents particularly suitable are those usually employed in milk processing. The amount of the anti-foaming agent is preferably less than 0,02%.

[0016] An example of the composition of an adhesive according to the present invention is indicated hereunder (with percentages on a weight basis):

• water   94,41%
• animal gelatin   5,19%
• potassium sorbate   0,3776%
• anti-foaming agent   0,018%
• citric acid up to pH 5,5 if required

[0017] The adhesive to be sprayed on the product is simply obtained by heating the water to about 40°C and by adding thereto the potassium sorbate and the anti-foaming agent, and the citric acid if required. Then the mixture is stirred by means of a stirrer, and the gelatin powder is poured very slowly in the center of the whirl generated by the stirrer, so as to avoid the formation of lumps which could clog the spray nozzle.

Claims

1. A process for labelling food products, characterized in that it consists in applying a layer of fluid adhesive on the surface of the product to be labelled, in subsequently placing on said layer a label made of light oozing tissue paper and in applying a layer of adhesive on the label too, said adhesive being an acqueous solution of an animal gelatin heated at a temperature included between 30°C and 50°C.

2. A process according to claim 1, characterized in that the adhesive is applied by spraying.

3. A process according to claim 1 or 2, characterized in that the gelatin employed is obtained from pigskin.

4. A process according to any of claims 1 to 3, characterized in that the gelatin employed has a strength between 220 and 280 Bloom degrees.

5. A process according to any of claims 1 to 4, characterized in that the solvent employed for dissolving the gelatin is water having a pH included between 5 and 5.5 and additivated with an antibacterial agent.

6. A process according to any of claims 1 to 4, characterized in that the solvent employed for dissolving the gelatin is a mixture of water and alimentary grade 99° ethanol, upto a proportion of 50% by volume.

7. A process according to any of claims 1 to 6, characterized in that the amount of gelatin dissolved in the acqueous solution is about 5% on a weight basis.

8. A process according to any of claims 1 to 7, characterized in that the solution further includes an anti-foaming agent, preferably in an amount lower than 0,02%.