DD267560A1 - PROCESS FOR QUALITY CONTROL OF FROZEN PRODUCTS - Google Patents

Abstract

Quality control procedures for frozen products, such as foodstuffs or other perishable goods, which are to be kept frozen prior to consumption and where any increase in temperature above 0C leads to deterioration or spoilage, especially in commerce, catering, pharmacy and medicine , According to the invention, the method is characterized by the use of test strips of absorbent products such as cellulose, which are cooled at temperatures below 0 ° C., then transferred to a physiologically acceptable dye dissolved in water so that a part of the test strip remains untouched, then immediately frozen again, To mark at the end of the dyed part by a marker, store it in a plastic source for protection against sublimation and the frozen material to be added to optically visible location, temperature increase at the frozen goods surface above 0C to thaw the dye dissolved in water and to continue the flow parallel to Temperature increase leads, whereby the marking is exceeded and displayed irreversibly.

Description

For this 1 page drawings

Field of application of the invention

The invention relates to a method for quality control of food or other perishable goods, which are to be kept in a frozen state prior to consumption and in which any increase in temperature over O ⁰ C leads to the reduction of quality or spoilage, especially in commerce, in medicine and in pharmacy.

Characteristic of the known technical solutions It is common for the preservation of food and pharmaceuticals to store them at temperatures below Me Freezing point of water. If this temperature is exceeded, this leads to Ve. Reduction of quality dos frozen-outes. Also short-term Thawing causes the quality is impaired, thereby thawing the frozen good on the surface, wherein after a

re-introducing the material into freezing temperature rooms, which does not freeze the material again as quickly as necessary to ensure quality so as to limit the growth of the ice crystals so as not to destroy the cell walls.

Devices are also known which indicate a critical temperature for the frozen product and are capable of using it

of electric energy to control the temperature in the climate chamber so that no impairment of the goods.

Devices are still known which, regardless of the presence of electrical energy anreioon, whether during Transport, handling or storage of the cold chain was interrupted. Such a device became, for example, in DE 1573279 proposed :. It is for commissioning a spring tensioned by means of a bimetallic element and

Another mechanism when critical temperatures a signal triggers, such as moving a color scale.

Such devices are always associated with a relatively expensive apparatus. It is retbar to operate economically ve> ⁴ at each Verbraucherverpackunij such an effort, since in addition to the direct impact on the cost bwch a reduction in the effective volume of packages or the freezer storage facility takes place. An application of these devices remains limited to individual packaging cases. In DE 2346598 an arrangement has been proposed for the identification of cooling stoppages in frozen goods, especially frozen foods, in the application of which indicator dye drops are applied to blotting paper, in the environment of which water-soluble basic substances have been placed. When the cold chain is broken, water vapor condenses on the packaged goods and on the indicator strips located there, with water collecting in the blotter, which causes the basic substance to diffuse into the area of the slurry in which the indicator is is located, which changes significantly after contact with this color. This solution has the disadvantage that it does not indicate the color change analogous to the temperature change. It takes up to 20 minutes. This period of time is particularly too long when it is to be reacted to rising temperature, since after such a long period of time, at least the surface of the material is already aufgeteut and thus subjected to a reduction in quality. Further uncertainty arises when these indicators are used in extremely dry climates or at temperatures only a few degrees above freezing because there the time to sufficient condensation of water vapor on the surface of the indicator strip is even longer. Due to the highly dependent on the ambient humidity and the ambient temperature function, this method is not sensitive enough to reliably detect an imminent interruption of the cold chain.

Object of the invention

It is the object of the inventions to develop methods which, due to its simple design, especially its small space requirement, can be used in all packaging of frozen food, without substantially increasing the cost of packaging, without additional energy and safety in that temperature increases on the surface of the frozen food are irreversibly visually displayed without a time delay.

Explanation of the essence of the invention

The invention has for its object to design a method that using known materials with minimal technological effort an irreversible visual display of minor but harmful increases in temperature of frozen material, even if they were only temporary, guaranteed. According to the invention, the object is achieved by a method of quality control of frozen products of the pharmaceutical and food industries, especially to control the preservation of the quality maintaining temperature, lower O ⁰ C, during transport, handling and storage, by optical means dependent and parallel to the unwanted temperature increase irreversible changed, characterized by the use of test strips of absorbent products such as cellulose, preferably blotting paper, which at temperatures below 0 ^c C, preferably in the temperature range of -5 ° C to -10 ° C to cool, then dissolved in water physiologically harmless dye, for example, in an aqueous food dye solution, so that a part of the test strip remains untouched by the dye and then immediately freeze it again, wherein at the end of the colored part on the test strip Grenzmarkierun g and the thus treated test strip the frozen goods to be stored immediately in a controllable place, visually visible or frozen storage is. The inventive method is further characterized in that in the case of Frhöhung de, -Temperatur on the frozen food over O ⁰ C thaw the water in the test strip with the dye dissolved therein, whereby at the same time interrupted by the freezing Fließvoryang the aqueous dye solution continues, the Dye solution exceeds the applied boundary mark and thus the irreversible visual indication of the temperature exceeded, wherein the test strip for protection against sublimation or unwanted deposition of ice crystals in the non-saturated part of the test strip in a, the size of the test strip adapted plastic sleeve is stored. In a second variant, the invention is characterized by the use of a test strip which consists partly of light and partly of blackened flowable material and is prepared in the already described erfinaungsgemäßen manner and due to the higher heat sensitivity of the blacked test strip part at temperature increases above the limit äc \ Dewing of the colored test strip part triggers earlier, which leads to the optical irreversible indication that the immediate Einle ':> ng of cooling measures for quality maintenance of the goods is required.

embodiment

The invention will be explained below using an exemplary embodiment. The accompanying drawings show:

Fig. 1: dry test strip with boundary marking

Fig. 2: partially colored, frozen test strips with boundary marking

Fig. 3: test strip with occurred by temperature increase exceeded the boundary marking

-3- 267 580

A test strip 1 made of blotting paper with a length of 5 cm and a width of 1 cm, is pre-cooled at a temperature of -5 ⁰ C. After removal of the strip 1 from the cooled space, it is poured into an aqueous food dye solution 3, e.g. B. Antocyanic solution immersed 2cm, wherein the flowability of the dye solution 3 is limited by the low temperature of the test strip 1 so that the test strip 1 colors only an additional centimeter. At this point, an optically visible boundary mark 2 was applied, whereby the test strip 1 is partially impregnated with the dye solution but is retained due to the ve'minderten by the strip temperature flowability. Following this, the test strip 1, which has been partially soaked with the dye solution 3, immediately returned to an ambient temperature of -5 ⁰ C and stored or added to the frozen material immediately. If the temperature rises on the surface of the meat where the test strip 1 is located, the state of aggregation of the aqueous food coloring solution 3 changes, this flows within 3 minutes in the to this time dry part 4 of the test strip 1, via the boundary marker second which indicates in a very simple way that the temperature of O ° C has been exceeded. To protect against the intended deposition of ice crystals or sublimation of the test strip 1 is surrounded by a 0.03 mm thick polypropylene shell.

Claims (3)

; Claim: • 1. ancestors for quality control of frozen food products, the j pharmaceutical industry and medicine, in particular to control the preservation of a j necessary temperature, lower O ° C, during transport, handling and storage, by optical j means which irreversibly change as a function of exceeding this temperature, characterized by the use of test strips (1) of absorbent products such as cellulose, preferably blotting paper, at a temperature below 0 ⁰ C, preferably in the temperature range! from -5 ° C to -10 ⁰ C, then in a physiologically dissolved in water ' harmless dye, preferably in an aqueous food dye solution (J), ! for example, antocyanic solution, with a temperature higher than ^{0 0} C, preferably in the range of j 2 ⁰ C to 5 ⁰ C, partially immerse so that one on the test strip (1) located i boundary marking (2) after the completion of the flow in the capillaries of the paper i is not exceeded by the food dye solution and then immediately into a Environment under O ⁰ C, preferably - 5 ⁰ C to -10 ⁰ C, in a suitable location, for example, to store or pack the frozen goods. 2. A method for quality control according to claim 1, characterized in that at a in the immediate vicinity of the invention prepared according to the test strip (1) vorsichgehenden ^; Temperature rise above the threshold of 0 ° C, the food Dye solution (3) changes their state of aggregation, in the up to that time dry part (4) ^: the test strip (1) irreversibly and in time flows analogous to the temperature rise, the I limit mark (2) exceeds and the temperature increase, even if only for a short time ; expires permanently indicating the test strip (1) to protect against sublimation or unwanted   Deposit of ice crystals in the non-saturated part of the test strip (1) in one of the size of the Test strip (1) adapted plastic sleeve is embedded. 3. A method for quality control according to claim 1 and 2, characterized by the use of a 'test strip (1), which consists partly of light and partly of blackened material and ; is prepared according to claim 1 and in the presence of a light source, due to the : higher heat sensitivity of blackened test strip part hot temperature increases above the set limit the thawing process in the colored test strip toilet earlier, that is in the; Temperature minus range, before reaching the 0 ° C limit, triggers what the optical irreversible Indicates that the frozen food surface is about to thaw and Redirect quality assurance measures.