JPH02173566A - Oxygen detector for low temperature - Google Patents

Abstract

PURPOSE:To detect oxygen at a high rate of discoloration and low oxygen concn. in a low-temp. region by utilizing the color reaction of an oxidation reduction dye which is limited in the compsn. ratios of a basic material and reducing saccharides and the concn. of hydrogen ions to specific ranges. CONSTITUTION:The effect of the basic material in a prepn. as reduction assistant is insufficient and, therefore, the rate of the color reaction is low if the ratio of the basic material/reducing saccharides (by weight) in the compsn. ratios of the basic material and the reducing saccharides is too low. the content of the reducing saccharides in the prepn. decreases and as a result, methylene blue is not sufficiently reduce and the sufficient color reaction does not progress if the above-mentioned ratio is excessive. The more preferable ratio of the basic material/the reducing saccharides (by weight) is in a 0.5 to 1.2 range. The rate of the color reaction depends on the pH of the mixture composed of the respective components; the rate is higher as the pH is higher. The reaction progresses stable in the low-temp. region as well in this case. The more preferable pH of the mixture is in a 10.5<=pH<=11.5 range. The rate of the color reaction sufficient for practicability is obtd. even in the low-temp. region in the above-mentioned range.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an oxygen detection agent, and more particularly to an oxygen detection agent that utilizes the coloring reaction of a redox dye and has an improved response speed in a low temperature range. .

The oxygen detecting agent of the present invention is used as a detecting agent for sensing the effectiveness of an oxygen scavenger that is enclosed in food packs and the like to prevent deterioration and spoilage of foods and the like due to oxidation.

Since the response speed is particularly fast in the low temperature range, it is suitably used for sensing the effectiveness of oxygen scavengers used in conjunction with low temperature storage in refrigerators and the like. It can also be used to detect air leaks in anaerobic microbial reactors.

(Prior Art) Oxygen detection agents that utilize the color reaction of redox dyes have been known for a long time, and various oxygen detection agents have been used.

A typical example is a tablet made by compressing a mixture of a redox dye such as methylene blue, a reducing sugar such as D-glucose, and a solid basic substance such as an alkaline earth metal oxide (Japanese Patent Application Laid-Open No. 024906, etc.).

[Problem that the invention seeks to solve]

In recent years, methods that combine oxygen absorbers and low-temperature storage have been adopted to preserve foods and products, especially semi-dried seafood products and foods with relatively high moisture content such as fresh sweets. A method has come to be adopted in which an oxygen detection agent is enclosed in a pan cage to determine the deoxidation state in the pan cage.

Existing oxygen detectors fully demonstrate their R performance in a relatively dry room-temperature atmosphere, but they cannot be used when packaged with semi-dried seafood stored at low temperatures, fresh sweets, or other relatively moisture-rich foods. When used in a laboratory, the atmosphere is high humidity and low temperature, which not only results in insufficient performance of the detection agent (such as a significant delay in discoloration of 1 hour), but also makes it more likely to absorb moisture and disintegrate. In particular, dyes may be eluted onto the surface of the preparation and transferred to the packaging material of the preparation, food packaging material, food itself, etc.

An object of the present invention is to provide an oxygen detection agent that can be stably used in a high humidity and low temperature atmosphere.

[Means for solving problems]

As a result of intensive research to achieve the above object, the present inventors discovered that basic substances/reducing IJ! m(
The present invention was completed based on the discovery that the response speed in a low-temperature and high-humidity atmosphere can be improved by limiting the weight ratio) and the hydrogen ion concentration of the formulation to a specific range.

The present invention provides basic substance/reducing IJ! Analogy (weight ratio) is 0.5 to 1.2 and hydrogen ion concentration is 10.5≦pH
A low-temperature oxygen sensor comprising a formulation formed from a mixture of methylene blue reducing Ws buffered to a range of ≦11.5, a basic substance, aluminum hydroxide, and optionally added additives. It is a drug.

In the present invention, the basic substance is used in combination with methylene blue and reducing m-classes as a reduction aid in the reduction reaction of methylene blue.

Examples include pl (basic substances with warming ability, preferably solid at room temperature) such as alkali metal salts and alkaline earth metal salts of weak acids such as phosphoric acid, carbonic acid, silicic acid, boric acid, and percussion acid. Basic substances are used.

Methylene blue is a typical redox dye that is colorless in its reduced form and blue in its oxidized form, and is blended as a coloring component in oxygen detectors. Instead of methylene blue, redox dyes such as nie methylene blue, Rouss violet, methylene green, and complex salts of methylene blue can also be used.

The reducing sugar is blended as a component that reduces methylene blue in the presence of a basic substance and maintains it in a colorless reduced form. For example, D-glucose, D-xylose, D-lactose, D-galactose, etc. can be used, and D-glucose and/or D-galactose can be used.
- Xylose is preferably used.

Aluminum hydroxide is used as a carrier for supporting each of the above-mentioned components during formulation.

As additives that may be added as desired, a binder, an aqueous modifier, a masking agent, a coloring agent, etc. are used.

The binder is a binder added when a mixture of each component is formulated into granules, tablets, etc., and a II3 aqueous binder is used. As the Ia aqueous binder, poorly water-soluble binders used in ordinary pharmaceutical preparations, such as poorly water-soluble cellulose derivatives such as ethyl cellulose, polyvinyl acetal diethylamino acetate (AEA), cellulose acetate phthalate (CAP), shellac, etc. Water-soluble polymeric substances and mixtures of two or more thereof are preferably used.

The tn aqueous adjuster is added to adjust the water repellency of the formulation, and is a substance with appropriate water solubility that is used in combination with the ta aqueous binder. As a t8 aqueous conditioner,
Hydrophilic binders used in common pharmaceutical preparations, such as polyvinyl alcohol, methylcellulose, polyacrylic acid and its salts.

One or more types of natural or synthetic water-soluble polymeric substances such as hydroxypropylcellulose are preferably used.

The hiding agent is preferably a white pigment such as titanium oxide, which is added for the purpose of clarifying the color development of the preparation.

Food additives are preferably used as the coloring agent, considering that the preparation is used in food packaging.

The mixed composition of each component is methylene blue 20°001
~10% by weight, preferably 0.03-0.15% by weight,
Reducing sugar: 1 to 30% by weight, preferably 1 to 10% by weight, basic substance/reducing sugar M (weight ratio): O, S to 1.
2. Preferably 0.7 to 1.0, binder: 4 to 20% by weight, 1N aqueous modifier 20.1 to 2.0% by weight, other additives such as hiding agents: a small amount, and aluminum hydroxide: the balance The hydrogen ion concentration of a slurry obtained by dissolving and dispersing 5 g of the mixture of each of the above components in distilled water to a total amount of 100 g is buffered and maintained within the range of 10.5≦pH≦11.5.

The oxygen detecting agent of the present invention comprises a mixture of the above-mentioned components in granules,
It is a preparation formed into any easy-to-handle dosage form such as a tablet.

A known method can be employed as a method for manufacturing the formulation. For example, water-soluble components are mixed well as an aqueous solution, solvent-soluble components as an organic solvent solution, and solid components such as carriers are mixed well as a solid, and the water and organic solvent are evaporated and dried by heating with stirring to form granules. can be manufactured. Moreover, tablets can be manufactured by adding a lubricant such as calcium stearate to the granules and compressing them by a conventional method.

[For production]

The oxygen detecting agent of the present invention is an oxygen detecting agent that utilizes the coloring reaction of a redox dye, and the composition ratio of the basic substance and reducing tJi as its components and the hydrogen ion concentration are limited to a specific range. Features.

In the present invention, methylene blue has a reducing property of tJ! in the presence of a basic substance in an oxygen-free atmosphere. It is reduced by 1 and changes color from blue to colorless. That is, the basic substance has the effect of adjusting the coloring reaction rate of methylene blue as a reduction aid in the reduction reaction of methylene blue with reducing sugars.

Therefore, the composition ratio of basic substances and reducing sugars is important in advancing the color reaction, and
If the reducing property level 1 (weight ratio) is too low, the basic substance in the formulation will not function sufficiently as a reducing agent, resulting in a decrease in the rate of coloring reaction, and if it is too high, The reducibility of IJ! As a result, methylene blue is not sufficiently reduced and a sufficient color reaction does not proceed. The preferred basic substance/reducing sugar m (weight ratio) is 0.5 to
1.2, more preferably 0.7 to 1.0
Adopt a range of

Further, the coloring reaction rate depends on the hydrogen ion concentration (pH) of the mixture of each component, and the higher the pH, the faster the reaction progresses stably even in a low temperature range. However, p
If the H content is too high, the coloring reaction will be promoted, but at high oxygen concentrations, the reaction of decolorizing methylene blue will proceed, and the function as an oxygen detection agent may be lost. The preferred hydrogen ion concentration of the mixture is 10.5≦pH≦11.5.
Within this range, the coloring reaction rate is practically sufficient even in a low temperature range and does not lead to excessive reaction, and more preferably, the p of the mixture of each component is within the range of
) I is buffered and maintained within the above range.

〔Example〕

The present invention will be explained in more detail with reference to Examples and Comparative Examples.

However, the scope of the present invention is not limited in any way by the following examples.

In addition, in the following examples, "part" and "%" are based on heavy M unless otherwise specified.

(11 Manufacture of oxygen detection agent Aluminum hydroxide: 368.5 parts, Titanium oxide (1
! ! ! screening agent): 20.0 parts and ethyl cellulose (t
n aqueous binder): Charge an ethanol solution containing 50 parts into a Nigu, mix under heating to evaporate part of the ethanol, and then add an ethanol solution containing 4 parts of methylene blue = 0° and Red No. 106. (Colorant): 0.04
of ethanol was added thereto, and the mixture was heated and mixed to evaporate almost all of the ethanol. Next, an aqueous solution containing 1 part of polyvinyl alcohol (water repellency modifier) was added, mixed with heat and dried, followed by 35 parts of D(+)-xylose (reducing sugar m) and trisodium phosphate. 1
Adding an aqueous solution containing 25 parts of dihydrate (basic substance),
Granules were obtained by heating and drying.

The moisture content in the obtained granules was 3.5%.

To 500 parts of this granule, add calcium stearate (lubricant 7
FI): 10 parts were added and mixed, and the mixture was compressed into tablets using a tablet machine to produce an oxygen detector sample A-1 consisting of a blue tablet.

Type of basic substance and composition N (basic substance/reducing t
J! Samples A-2 to A-4 and comparative samples CA-1 to C were treated in the same manner as sample A-1 except that the M ratio was changed.
8-4 was manufactured.

The compositions of each sample and comparative sample obtained are shown in Table 1.

(2) Various tests The following tests were conducted on each sample produced in the above item (1) and the granules before sample production, and the test results are shown in Table 1.

(Al Hydrogen ion concentration Dissolve 5 g of granules of each sample before forming into tablets in distilled water,
A slurry was prepared in which the slurry was dispersed to a total amount of 100 g, and the hydrogen ion concentration of this slurry was measured using a pH meter.

(bl Color change rate Several samples of each sample were sealed in a nitrogen atmosphere with an oxygen concentration of 0.1% by volume or less and kept at 5°C, and the time required for the sample to discolor from blue was measured. The average value was determined and used as the discoloration rate.

(C1 discoloration Oxygen concentration Several samples of each sample were sealed in atmospheres with different oxygen concentrations, kept at 20° C., and left for 24 hours.

The color tone of the sample at each oxygen concentration was measured, and the oxygen concentration at which the sample was decolored from blue was measured, and the average value was taken as the discoloration oxygen concentration.

As shown in Table 1, basic substance/reducing tl! M
(weight ratio) and hydrogen ion concentration are both within the range of the present invention (see Examples), the discoloration rate and discoloration oxygen concentration are within a practical range, although there are some differences in the discoloration rate. On the other hand, basic substances/reducing properties 1! If either (weight ratio) or hydrogen ion concentration is outside the range of the present invention (see Comparative Examples), the rate of discoloration is extremely slow or discoloration occurs at high oxygen concentrations.

〔Effect of the invention〕

As shown in the above examples, the oxygen detecting agent of the present invention has 5
Even in the low temperature range of °C, the rate of discoloration is fast and discoloration occurs at low oxygen concentrations.

Therefore, Yozuki can be used as a detection agent to detect the presence of oxygen in low oxygen concentration atmospheres such as the storage atmosphere of oxygen absorbers, food storage packages containing oxygen absorbers, and anaerobic microbial reaction tanks, especially in low temperature regions. Because of its excellent properties, it is suitable as an oxygen detecting agent to be used together with an oxygen absorber in the packaging of foods that are kept refrigerated.

INDUSTRIAL APPLICABILITY The present invention provides an oxygen sensing agent with excellent oxygen sensing properties, particularly in a low temperature range, and has extremely great industrial significance including the food preservation field.

Claims (1)

[Claims] (1) Basic substance/reducing saccharide ratio (weight ratio) from 0.5 to
1.2, and the hydrogen ion concentration is 10.5≦pH≦11.
A low-temperature oxygen detecting agent characterized in that it consists of a formulation obtained by molding a mixture consisting of methylene blue, reducing sugars, basic substances, aluminum hydroxide, and additives added as desired, which are buffered in the range of 5.