WO1997011341A1

WO1997011341A1 - Device for identifying and for quantifying of interruptions in the freezing chain in deep-frozen or frozen products

Info

Publication number: WO1997011341A1
Application number: PCT/IB1996/000958
Authority: WO
Inventors: Nicola Massi
Original assignee: Nicola Massi
Priority date: 1995-09-19
Filing date: 1996-09-18
Publication date: 1997-03-27
Also published as: ITBO950438A0; IT1279633B1; ITBO950438A1; AU6887196A

Abstract

Device for identifying and for measuring the occurring of interruptions in the freezing chain for a deep-frozen or frozen product, consisting in a label (1) made with water absorbent material and provided with a strip (3) made with a water soluble substance on its inside face (1b), said strip (3) being capable to modify its colour by means of a chemical reaction with liquid water. The label (1) is also provided with an impermeable film (4), in its whole surface except for a terminal portion (5), which is able to absorb liquid water and to allow its spreading toward the inside of the label (1).

Description

DEVICE FOR IDENTIFYING AND FOR QUANTIFYING OF INTER¬ RUPTIONS IN THE FREEZING CHAIN IN DEEP-FROZEN OR FROZEN PRODUCTS

TECHNICAL FIELD

The present invention refers to a device for detecting that at least one interruption in the freezing chain of deep-frozen or frozen products has occurred, that is to the accidental attainment, by the same products, of a temperature higher than the de-freezing temperature, and for approximately measuring the duration of the permanence of the products in such conditions.

BACKGROUND ART

It is known that alimentary products which are preserved by means of deep-freezing or freezing must comply to conditions of continuity of the so¬ called "freezing chain", in order to preserve their nutritional, organoleptic and hygienic integrity, starting from the moment at which they are deep- frozen up to the moment when they are consumed. Such products must not be subject, during all the preser¬ vation period, to even partial de-freezing and re- freezing events.

In fact, an interruption of the freezing chain causes the alimentary products to be subject to decay phenomenons starting from a remarkable decrease of their nutritional power, up to toxins production and to bacterial colonies proliferation. It is in any case greatly unadvisable to eat the deteriorated products, and their sale is also for- bidden by law. A temporary de-freezing of a product, followed by a subsequent re-freezing, is not easily recognis¬ able to the view, except for some cases and for some products. Some empirical elements of evaluation are, for instance, the presence of an ice layer or of a frost layer on the package, a certain moisture in the cardboard packaging (for products which are packaged in boxes) , or the scarce product stiffness at the touch. These elements cannot however prove that the product has been certainly de-frozen.

A known procedure for detecting of at least one interruption in the freezing chain for alimen¬ tary products is, by example, the one described in the Patent Application N. MI92A 000526, filed by the same Applicant.

According to the solutions described in the above patent application a label is provided, which is subject to chromatic, irreversible chemical reactions following to its contact with liquid water. The label could be fixed for instance to the inside face of the transparent cork of a small container, filled with a water-based gelatinous solution, that solidifies at the normal freezing temperatures of the product to be monitored, and that at contrary melts and releases liquid water at temperatures close to zero degrees centigrade .

The container is normally cooled and applied to the previously frozen product, so that the gelati¬ nous solution that it contains is in a solid state. If at an any moment the container reaches a tempera¬ ture close to zero degrees centigrade, the solution contained therein tends to melt, thus freeing liquid water that wets the label. That causes an irrevers¬ ible chemical reaction, causing a colour variation in the label that results visible from the outside through the transparent cork.

In the above cited patent Application, some different types of substances capable of chromatic¬ ally reacting with water are described, and that can therefore be suitably used to reach the above stated purpose, for instance by applying it on the label with serigraphic methods or by means of a painting process. Eventually, some surface-active agents or organic solvents can be moreover applied to the same label.

It is alternatively possible, in some cases, the direct application of the water-reactive label to the package. In this case the liquid water that interacts in case of overcoming of the critical temperature is provided by the condense that depo¬ sits on the package or on the product.

The above described solution, although being capable to provide sufficiently precise information about the occurring of possible interruptions in the freezing chain, is not able to provide any quantita¬ tive information, as far it regards the duration of the period during which the product has remained in a condition of partial or total de-freezing.

The availability of this quantitative infor- mation is very important both for the dealer and for the user, since it would allow them to under¬ stand if the overcoming of such critical temperature concerns only the packaging itself without concern¬ ing the whole product, and if major alterations in the product integrity can have occurred, enough to suggest to throw away the same product .

It is an object of the present invention to propose a device which is capable to clearly and visibly identify that at least one interruption in the freezing chain for a deep-frozen or frozen product has occurred, such device being further capable to give some information either about the approximate duration of said interruption, or about the cumulative duration of the occurred interrup¬ tions, if more than one interruption has occurred.

A further object of the present invention is to achieve the above stated results by means of a device of simple making, of high reliability and of very low cost.

DISCLOSURE OF THE INVENTION

All the aforesaid objects are achieved by a device for identifying and quantifying of interrup- tions in the freezing chain in deep-frozen products, which is placeable into contact with the product to be monitored, such device being provided with a label capable to be subject to irreversible chro¬ matic reactions by consequence of a contact with liquid water, being also said device fit to quantify the overall duration of said interruptions in the freezing chain, and being characterised in that the said label is made with a substance having a high water absorption rate and it is provided with iden- tification means, capable to be subject to irrevers¬ ible chromatic reactions by consequence of a contact with liquid water, being the said label also provi¬ ded with impermeabilization means, for the most part of its surface staying in contact with the product being monitored, said impermeabilization means being fit to allow the water absorption by only a terminal portion of said label not covered by said impermea¬ bilization means, and to allow said identification means to progressively come into contact with liquid water. BRIEF DESCRIPTION OF THE DRAWINGS

The characteristic features of the invention are set out in the following, with particular refer- ence to the accompanying drawings, in which:

- Figure 1 shows a schematic perspective view of a preferred embodiment of a device for identifying of any interruption in the freezing chain, according to the present invention; - Figure 2 schematically shows the device of Figure

1, seen from the user visible side, subsequently to a de-freezing event;

- Figure 3 schematically shows the device of Figure

2, seen from the side which is in contact with the monitored product;

- Figure 4 shows a schematic perspective view of a second embodiment of the device according to the present invention.

BEST MODE OF CARRYING OUT THE INVENTION

With reference to the figures from 1 to 3 , numeral 1 indicates a label, having an approximately rectangular shape, made with water absorbent paper, or with some other material having a high water absorption power. In an inside face lb of the same label, a longitudinal strip 3 is applied, by means of painting, of a serigraphic process or some other suitable process. That longitudinal strip 3 is made of a water soluble material, which is also able to clearly vary its colour subsequently to a reaction with liquid water.

The label 1 is fit to be placed with a direct contact to the deep-frozen product, or at least with the product packaging, having its inside face lb turned toward the same product.

In a preferred embodiment of the present invention, the label 1 is wrapped by an impermeable film 4 on its whole surface, except for a terminal portion 5, which on the contrary is not wrapped by that film 4. This latter is preferably applied on the label 1 by means of a known serigraphic process, but it can be also advantageously made of a sheet of a transparent plastic material, which is fixed to the label 1 by using some adhesive substances, or it can be made of a transparent and impermeable layer applied by painting.

The external face la of the label 1 which is turned toward the deep-frozen product user is raore- over provided with a graduated scale 6, also made by means of a painting process, of a serigraphic pro¬ cess or any other known process. It can be provided or not with some explanatory numbers or writings.

A second embodiment of the invention, which is illustrated in Figure 4, requires an impermeable film 4, placed in a direct contact with only the inside face lb of the label 1, for the whole exten¬ sion of said inside face lb except for the terminal portion 5. Preferably, the film 4 is sideways wider then the aforesaid inside face lb, so as to define external lateral borders 7a, 7b, fit to avoid a water lateral flow toward the label 1.

Of course, also with regard to the above described second embodiment, the film 4 is applied to the label 1 according to the same application modes previously illustrated for the firεt embodi¬ ment .

The present device for identifying and for quantifying any interruption in the freezing chain i_s usually joined with its relative deep-frozen or frozen product, having the impermeable film 4 and the terminal portion of the label 1 into a direct contact with the product surface, or at least with the product packaging. Until when the product stays in a freezing state, that is at temperatures which are sensibly under zero grades centigrade, it doesn't produce liquid water, since said water stays in a ice or frost state. As the surface temperature of the product reaches or overcomes zero degrees centigrade, a production of liquid water occurs, both because the product itself releases some of its natural humidity and because the frost which has settled on the product surface tends to melt.

In this case the terminal portion 5 of label 1 soaks up the water which to it comes into contact, gradually spreading it toward the label portion which is protected by the impermeable film. In this way the water comes also into contact with the portion of strip 3 near to the terminal portion 5, thus causing the substance forming the strip 3 to melt into water and also causing said substance to change its colour. It moreover spreads across the label 1 thickness, until it appears on the external face la of this latter. The coloured substance is thus visible to the product user.

The strip 3 melts progressively, as soon as water penetrates inside the label 1. The visual effect obtained on the external face la (see Figure 2) is a coloured strip progressively increasing its length, to an amount which is substantially propor¬ tional to the duration of interruption of the free¬ zing chain. The graduate scale 6 placed on the external face la, together with some possible expla- natory writings, makes the interpretation of said duration easier, in terms of understandable measur¬ ing units (minutes, hours, etc.).

If seen from the inside face lb the strip melting effect would appear as a strip progressively changing its colour, starting from the terminal portion 5.

It is also obvious that a subsequent tempor¬ ary temperature fall under zero degrees centigrade would result in a freezing of water in the label 1. This would stop the water spreading inside the label 1. Said spreading resumes just when temperature raises again above zero degrees centigrade.

With regard to the second embodiment of the invention (Figure 4), which is of easier making, the operation procedure is identical to that already described for the first embodiment . The solutions according to the second embodiment nevertheless can be only applied where there is no water flow to the label 1 coming from its external face la.

The advantages that it is possible to achieve by means of the device of the present invention substantially comprise the possibility, both for an user and for a dealer, not only to have a precise information about the occurring of one or more interruptions in the freezing chain, but also to have some information about the overall duration of said interruptions. This leads to a good evaluation about possible organoleptic alterations in the ^ monitored product, and about some possible bacterial proliferations inside it, that could make its con¬ sumption dangerous to human health, or that could modify its nutritional features, even keeping the product edibleness. ^ A further advantage which is achievable with the present invention is that the water soluble chemical substances, contained in the label 1, don't come into contact with the deep-frozen product in any case, since this latter is protected by the impermeable and transparent film 4. This is a war¬ ranty for the total hygiene and safety of the mon¬ itored product.

The subject invention has been obviously de¬ scribed, with reference to the attached drawings, for exemplifying and not limitative purposes, and it is therefore evident that it is possible to apply to it all of those modifications or variations suggested by the practice and by its realisation and use, however included in the field defined by the following claims.

Claims

1. A device for identifying of interruptions occurred in the freezing chain in deep-frozen pro- ducts, of the kind placeable into contact with the product to be monitored, such device being provided with a label (1) capable to be subject to irrevers¬ ible chromatic reactions by consequence of a contact with liquid water, being also said device fit to quantify the overall duration of said interruptions in the freezing chain, and being characterised in that the said label (1) is made with a substance having a high water absorption rate and it is provi¬ ded with identification means (3) , capable to be subject to irreversible chromatic reactions by consequence of a contact with liquid water, being the said label (1) also provided with impermeabili¬ zation means (4) , for the most part of its surface staying in contact with the product being monitored, said impermeabilization means (4) being fit to allow the water absorption by only a terminal portion (5) of said label (1) not covered by said impermeabili¬ zation means (4) , and to allow said identification means (3) to progressively come into contact with liquid water.

2. Device according to Claim 1, characterised in that said identification means (3) is made by at least a strip of a water soluble substance applied by a painting process, by a serigraphic process or some suitable application process, to a face of the said label (1) , the said substance being also sub¬ ject to visible colour variations following to a chemical reaction with the said water.

3. Device according to Claim 2, characterised in that said strip (3) is applied on the inside face (lb) of said label (1) which is turned toward the product to be monitored.

4. Device according to Claim 1, characterised in that the said impermeabilization means (4) con- sists of a transparent film, wrapping the whole label (1) , except for the said terminal portion (5) of said label (1) .

5. Device according to Claim 1, characterised in that the said impermeabilization means (4) consists of a transparent film, applied on the inside face (lb) of the said label (1) .

6. Device according to both Claim 4 or Claim 5, characterised in that said transparent film (4) is applied on the said label (1) by means of a serigraphic process.

7. Device according to both Claim 4 or Claim 5, characterised in that said transparent film (4) is applied on the said label (1) by means of a painting process.

8. Device according to both Claim 4 or Claim

5, characterised in that said transparent film (4) is pasted to the said label (1) .

9. Device according to Claim 1, character¬ ised in that it comprises at least a graduate scale (6) , applied on a face of the said label (1) and fit to make reading of information provided by said label (1) easier.