FR2671401A1 - Temperature checking device for frozen and deep-frozen foodstuffs - Google Patents

Abstract

Device making it possible to check, mainly in the deep-frozen and frozen food industry, whether the cold chain has been broken. This invention consists of a small, rigid and transparent leaktight casing (4), comprising: - a compartment (1) completely filled with a solution of salt water containing a measured amount of NaCl so that it freezes at a temperature defined in relation with the nature of the foodstuff to be checked and its statutory preservation temperature. - a compartment (2) partially filled with the same salt solution, but coloured, - a thin wall (3) which will break on the first solidification of the solution in the compartment (1), because this change of state leads to an increase in volume. This device is fixed on or in the package of the product to be frozen or deep-frozen and displays whether or not an increase in temperature beyond the defined statutory temperature has taken place.

Description

FILING OF A PATENT DEPM
DESCRIPTION
The present invention is a device for checking, mainly in the frozen or frozen food industry, whether the cold chain has been broken.

 This device consists of a waterproof and rigid case, comprising two sealed compartments separated by a thin wall that does not withstand great pressure.

 Figure 1 shows in section, the device according to the invention.

 Figure 2 shows in section, a variant of this device.

 With reference to these drawings, the device comprises a compartment (1) filled to the brim with a salt water solution dosed with sodium chloride so that the solidification point of this solution is situated at a suitably chosen temperature. This chosen temperature is linked to the nature of the frozen or deep-frozen foodstuffs, as indicated in the å official journal of the French Republic under the heading of general hygiene texts: food.

 Still with reference to these drawings, the device comprises a compartment (2) partially filled, for example one third, with the same solution as that of compartment (1) with the same concentration of sodium chloride, but colored. Depending on the temperature chosen, a particular coloration of the solution is defined.

 Also with reference to these drawings, the device comprises a thin wall (3) not resistant to high pressure, unlike the external wall constituting the housing (4) of this invention.

The operating principle is as follows:
When packaging the food, our device is placed inside its packaging if it is transparent, or placed outside of its packaging using adhesive means, for example. At room temperature, the solutions in compartments (1) and (2) are liquid and are always separated by the wall (3). We visualize in compartment (1) a transparent solution and in compartment (2) a colored solution.

 If the temperature drops to the point where the saline solution solidifies, the salt water in the freezing compartment (1) will increase in volume. As this compartment is completely filled, this change of state, from liquid to solid, linked to an increase in volume, will cause a rupture of the wall (3). The solution in compartment (2) will also freeze, but the increase in volume is facilitated by partial filling of this compartment. At this stage, we visualize a transparent white solid mass corresponding to the salted strip of the compartment (1), and a colored mass corresponding to the colored salted water of the compartment (2).

 If the temperature increases above the point of solidification of the liquids, the wall (3) having been broken, the two liquids will then mix, and we visualize the same liquid of the same coloring.

 If the temperature drops again below the point of solidification of the liquids, we therefore visualize the same solid mass of the same color.

 The housing (4) of this device must of course have sufficiently solid external walls and these walls must be transparent to view the results.

 By way of nonlimiting example, the case will have dimensions of the order of 1 cm for the width, 3 cm for the length and 0.5 cm for the height.

 The device according to the invention is particularly intended for checking whether the frozen or deep-frozen foodstuffs have not undergone a temperature increase, incompatible with the quality of these foodstuffs.

Claims (5)

 1) Device for controlling, mainly in the frozen or deep-frozen food industry, whether the cold chain has been broken, characterized in that it comprises a sealed, rigid and transparent casing (4) having two compartments ( 1) and (2) separated by a wall of lesser thickness (3) which does not withstand great pressure.  2) Device according to claim 1 characterized in that the compartment (1) is completely filled with a salt water solution, dosed with NaCl so that its solidification point is located at a temperature defined in relation to the nature of the food to be checked and its regulatory storage temperature *.  3) Device according to claim 1 and claim 2 in: that the compartment (2) is partially filled with a salt water solution of the same NaCl concentration as the solution in the compartment (1) but which is on the other hand colored .  4) Device according to any one of the preceding claims in that the increase in volume of the liquid in the compartment (1) when lton reaches its solification temperature, causes the wall (3) to rupture.  5) Device according to any one of the preceding claims in that the liquid in the compartment (2) is colored in a different color corresponding to a regulatory classification of the official journal of the French Republic according to the nature of the frozen or deep-frozen foodstuffs and their storage temperature.