JPH0352579B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an oxygen detection agent, and more specifically, to an oxygen detection agent containing one or more compounds selected from the group consisting of phosphites and hypophosphites (hereinafter referred to as phosphite compounds). This invention relates to an oxygen detecting agent in the presence of water that is made of a redox dye. Oxygen detection agents allow the presence or absence of oxygen in a sealed atmosphere to be determined with the naked eye by a change in color tone, and the change in color tone is reversible in the presence and absence of oxygen. It has the great feature of being highly accurate. In particular, with the recent development of so-called K-coated plastic film coated with vinylidene chloride resin for food packaging, gas barrier properties against inorganic gases such as oxygen and carbon dioxide have rapidly improved, resulting in vacuum packaging, gas displacement packaging, and the use of oxygen absorbers. Various packaging methods have been developed for the purpose of removing oxygen, such as packaging, and their use is rapidly increasing. Foods packaged using these various packaging methods are all inexpensive and are manufactured in large numbers. When analyzing oxygen in the atmosphere inside the packaging of these foods using conventional oxygen gas analyzers such as polarography, galvanic cell analyzers, stabilized zirconia analyzers, etc.
In order to sample the gas inside the packaging container or bag during analysis, it is necessary to make a hole in the container or bag, which not only looks unsightly but also may impair the oxygen gas barrier performance. Furthermore, all of these analyzers are expensive and require a considerable amount of analysis time, and therefore cannot be said to be a good analysis method from an economical point of view. On the other hand, oxygen detectors can be used in the same atmosphere as the food, such as by enclosing it when packaging the food, so that the oxygen inside the packaging container or bag can be detected without causing any damage to the packaging container or bag. Since it has the great advantage of being able to determine the presence or absence of oxygen with the naked eye in a short period of time, there is a need for the development of an inexpensive, safe, and more effective oxygen detection agent. Currently, liquid or solid oxygen sensing agents are known to meet this demand, but none of them are satisfactory. For example, an oxygen-detecting agent consisting of the redox dye methylene blue, sugars, and sodium hydroxide is used as an oxygen-detecting agent when performing anaerobic fermentation in the fermentation industry, but the sugars and sodium hydroxide in it are The problem is that the oxygen detector reacts with oxygen and loses its original function as an oxygen detector. Also, hydrosulfite, dithionite,
Oxygen detection agents that contain reducing agents such as ferrous salts and redox dyes as essential components are also known, but since the oxygen detection sensitivity is approximately 0.1% by volume or more in terms of oxygen concentration,
It is particularly inappropriate when applied to foods that are affected by trace amounts of oxygen. Therefore, the present inventors conducted repeated studies to develop an oxygen detector that is inexpensive, safe, and easy to handle, and can even detect low concentrations of oxygen in the atmosphere. I found it. That is, the present invention is an oxygen detecting agent in the presence of water, which is composed of one or more compounds selected from (sub)phosphite compounds and a redox dye. The (sub)phosphite compound constituting the oxygen detecting agent of the present invention includes phosphorous acid, an alkali metal salt or an alkaline earth metal salt of hypophosphorous acid, and preferably a sodium salt, a potassium salt, These include calcium salts, magnesium salts, barium salts, etc. Specific examples of particularly preferred compounds include sodium phosphite, magnesium phosphite, sodium hypophosphite, and calcium hypophosphite.
Moreover, there is no problem even if these metal salts are hydrates containing water of crystallization. Further, the redox dye, which is another component constituting the oxygen detecting agent of the present invention, is a dye whose color tone varies depending on the oxidation state and the reduction state, such as methylene blue, new methylene blue, Eisenmethylene blue, and toluidine blue. , acid blue, methylene green, safranin, meldora blue, etc. In the present invention, the blending ratio of the (next) phosphite compound and the redox dye is not particularly limited as long as the amount of the redox dye to be blended is an amount that exhibits the function as an oxygen detector, but usually (next) ) It is preferable that the amount of the redox dye be 0.001 to 13% by weight, more preferably 0.01 to 5% by weight, based on the total amount of the phosphite compound and the redox dye. Redox dye is 0.001
If it is less than 13% by weight, the resulting oxygen detecting agent will have little coloring, making it difficult to judge the change in color tone due to the presence or absence of oxygen, and even if it is more than 13% by weight, the degree of coloring will not increase, and dyes are generally expensive. Therefore, it also causes an economic loss, which is not desirable. A major feature of the oxygen detector of the present invention is that it has higher oxygen detection sensitivity than conventional oxygen detectors and retains the ability to detect even trace amounts of oxygen. That is, conventional oxygen detecting agents, such as oxygen detecting agents consisting of a combination of methylene blue, sodium hydroxide, and sugars, have an atmospheric oxygen concentration of about
While the color tone of the oxidized and reduced forms mutually changes at around 0.1% by volume, the color tone of the oxygen detecting agent of the present invention changes mutually at an even lower concentration, that is, around 0.05% by volume, and this feature This makes it possible to apply this method particularly to foods that deteriorate due to trace amounts of oxygen, such as cut rice cakes. In order for the oxygen sensing agent of the present invention to perform its function, the presence of water is necessary. Therefore, for example, water may be added during the production of an oxygen detector, or an inert crystal water-containing compound that does not impair its function as an oxygen detector, such as sodium sulfate decahydrate or sodium carbonate decahydrate. etc. are added.
Furthermore, when packaging high-moisture foods, the partial pressure of water vapor inside the packaging container or bag increases, so even if water or a crystal water-containing compound is not specifically added to the oxygen detecting agent of the present invention, water vapor can be It becomes possible to replenish the supply of The amount of coexisting water in which the oxygen sensing agent according to the present invention effectively exhibits its function is preferably 0.1 part by weight, more preferably 0.1 part by weight, per 100 parts by weight of the total amount of the (sub)phosphite compound and redox dye. is 0.5 part by weight or more. If the amount of coexisting water is less than this, the function will not be fully exerted because the amount of the (hypo)phosphite compound and redox dye dissolved in the water will be small. In addition, when water is added and blended during the production of the oxygen detection agent, the amount should be 50 parts by weight or less, more preferably 25 parts by weight, per 100 parts by weight of the total amount of the (sub)phosphite compound and redox dye. It is preferable that the amount is less than 1 part by weight, thereby preventing water from rising to the surface of the tablet when the oxygen detector is molded, for example, compressed into a tablet. If desired, fillers, alkaline compounds, dyes, etc. can be added to the oxygen detecting agent of the present invention as long as the function as an oxygen detecting agent is not impaired. Extending agents include silica, silica alumina, alumina, silica magnesia, zeolite, diatomaceous earth, silica gel, kaolin, talc and the like. In addition, the rate of change in color tone of the redox dye is adjusted,
Alternatively, alkaline compounds such as alkali metal or alkaline earth metal hydroxides, carbonates, hydrogen carbonates, silicates, etc. may be added to provide an oxygen detection function in a carbon dioxide atmosphere. Conventional oxygen detectors have a major drawback in that in a carbon dioxide atmosphere such as in carbon dioxide gas replacement packaging, alkaline compounds in the detector, such as sodium hydroxide, react with carbon dioxide gas and do not function as oxygen detectors. was. However, the oxygen detecting agent of the present invention can be made to function as an oxygen detecting agent even in a carbon dioxide atmosphere by adding, in particular, a hydrogen carbonate such as a sodium salt, a potassium salt, a magnesium potassium salt, etc. as an alkaline compound. This is due to the presence of bicarbonate,
until the oxygen detector does not absorb carbon dioxide gas.
This is because the pH decreases. The preferred blending amount of the above-mentioned extender and alkaline compound is 10 to 10 parts by weight, respectively, based on 100 parts by weight of the (sub) phosphite compound and redox dye.
It is 1000 parts by weight. Further, when a hydrogen carbonate is blended for the purpose of detecting oxygen in the presence of carbon dioxide gas, a more preferable blending amount is 100 to 800 parts by weight. When manufacturing the oxygen detection agent of the present invention, (next)
There are no restrictions on the order of addition of the phosphite compound, redox dye, water, and optionally an alkaline compound, filler, dye, etc. The oxygen detecting agent of the present invention can be used in the form of a powder obtained by simply mixing each component, or as a tablet formed by a tablet molding machine, etc., or can be used in any form such as an ink formed by using the oxygen detecting agent of the present invention as a pigment. It can also be used in any form. In any case, it is preferable from the viewpoint of food hygiene and safety to wrap at least one side with a film having high oxygen permeability to prevent direct contact with food. However, even in that case, it is necessary to use at least a partially transparent packaging material so that the color tone of the oxygen detector can be determined with the naked eye so as not to impair the original function of the oxygen detector. be. The oxygen detecting agent of the present invention can be used for fresh foods, processed foods,
Detecting incomplete deaeration and poor sealing of containers or bags in packaging methods such as vacuum packaging, gas replacement packaging, and packaging using oxygen absorbers used for oxidation prevention and preservation of organic chemicals, metal products, etc. I can do it. In addition, the oxygen detecting agent of the present invention has reversibility in color change in the presence and absence of oxygen, which prevents mechanical damage during the distribution stage of the package, such as the formation of pinholes and the sealing surface. It is also possible to detect peeling, etc. The present invention will be explained in more detail below using Examples and Comparative Examples. Examples 1 to 6 The redox dye, (sub)phosphite compound, and other additives listed in Table 1 were thoroughly mixed to obtain an oxygen detector powder. This was placed under an atmosphere as shown in Table 1, and changes in the color tone of the oxygen detecting agent were observed.
The results are shown in Table 1.

【table】

[Table] Example 7, Comparative Example 1 The redox dye, hypophosphite (Example) or glucose (Comparative Example) listed in Table 2, and other additives were mixed well, and the oxygen detector powder was added. Obtained. This was placed under an atmosphere as shown in Table 2, and the color tone of the oxygen detector was observed. As shown in the results in Table 2, it is clear that the oxygen sensing agent of the present invention can detect trace amounts of oxygen.

[Table] Example 8, Comparative Example 2 Phosphite (Example) or glucose (Comparative Example) and hydrogen carbonate and other additives were thoroughly mixed with the redox dyes listed in Table 3 to form an oxygen detector. A powder was obtained. This was placed in an atmosphere containing carbon dioxide as shown in Table 3, and the color tone of the oxygen detector was observed.
As shown in the results in Table 3, it was found that the oxygen detector of the present invention to which an alkaline compound was added can sufficiently exhibit its function even in a carbon dioxide atmosphere.

【table】

Claims (1)

[Claims] 1. An oxygen sensing agent in the presence of moisture, comprising at least one species selected from the group consisting of phosphites and hypophosphites and a redox dye.