JPH0677514B2 - Food freshness preserving agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a freshness-retaining agent for foods containing an antibacterial material in which hinokitiol is supported on hydroxyapatite.

(Prior Art) As a method for maintaining the freshness of fresh foods, various methods such as adjustment of humidity, temperature, oxygen, ethylene, carbon dioxide gas, etc. when holding fresh foods and use of antibacterial agents and deodorants have been devised. The freshness is maintained by the combination of. In particular, freshness-keeping packaging of fresh food has been widely studied as a simple method. For example, it is generally known that when ceramics such as zeolite, hydroxyapatite, activated carbon, Otani stone, natural ore, etc. are added to the packaging material, they adsorb ethylene gas and thus are effective as a freshness-retaining agent. However, if such ceramics are simply added to the packaging material, the freshness-keeping ability is insufficient, and the gas permeability becomes poor depending on the amount added, so it is necessary to select it according to the purpose of the type and amount of ceramics. is there. Attempts have also been made to impart antibacterial properties to packaging materials. For example, kneading zeolite ion-exchanged with silver ions, and using a safe antibacterial agent, hinokitiol, by adhering it to packaging materials, synthetic resins, cellulose, SiO ₂ , and zeolite (Japanese Patent Publication No. Sho 61-108359). As described above, the ability to retain freshness is also increased by incorporating or adsorbing an oxidizing agent, an antibacterial agent, a preservative, a deodorant, an antifungal agent, or the like into ceramics or a synthetic resin. . However, selection of ceramics and chemicals is difficult, and depending on the chemicals, there is a possibility of contaminating food or causing problems in disposal, and if synthetic resin or cellulose is squeezed in, gas permeability is lowered, which is not preferable.
Hinokitiol is a natural product obtained from the spear and is a relatively safe drug, but when it is used by impregnating food packaging paper, it is relatively volatile, so it volatilizes during packaging and adheres to food. However, it may contaminate foods or lose its effect by volatilizing from the wrapping paper for a long period of time, and when used by adsorbing it on SiO ₂ , zeolite, etc., their hinokitiol holding amount is low, or their holding power is low. If it is too strong, the antibacterial action of hinokitiol is difficult to reveal, and a large amount of hinokitiol must be added to obtain antibacterial properties. Therefore, the property as a wrapping paper may be deteriorated.

(Problems to be Solved by the Invention) The present invention aims at a freshness-retaining agent that can be used for safe packaging with hinokitiol and hydroxyapatite, and may hinder the antibacterial effect of hinokitiol by volatilizing even if it is left for a long time. It does not volatilize and contaminate food during packaging, and unlike SiO ₂ and zeolite, it has an appropriate amount and holding power for hinokitiol.By adding an appropriate amount to the packaging material, ethylene adsorption and gas permeation into the packaging material can be achieved. The present invention provides a freshness-preserving wrapping agent having excellent antibacterial properties and antibacterial properties.

(Means and Actions for Solving Problems) Zeolite, Otaniishi, hydroxyapatite, etc. are considered as freshness-maintaining materials because they balance ethylene adsorption and gas permeation when added to a film for packaging materials. Among them, hydroxyapatite is the main component of bone, is the safest and harmless substance used for artificial bones, artificial tooth roots, calcium agents, etc., and is optimal for use in foods. However, since hydroxyapatite has a property of adsorbing proteins, amino acids, etc., it has a drawback that bacteria are remarkably adsorbed and bacteria easily propagate. Therefore, when hydroxyapatite is used as a freshness-maintaining material, it is necessary to pay particular attention to deterioration of fresh food due to bacterial contamination. For that reason,
Although it is possible to use an antibacterial agent, since the packaging material is likely to come into direct contact with foods, an antibacterial agent that is safe, does not evaporate, does not elute, and can be heat processed must be used. Therefore, the present inventors have carried out a study for the purpose of using a hydroxyapatite antibacterial material that retains the antibacterial agent so as not to elute, has antibacterial properties, and can be heat-processed, and as a result, adsorbs and supports hinokitiol on the hydroxyapatite And, the supported hinokitiol is stabilized against heat, does not volatilize or deteriorate, and is not eluted in water, and its antibacterial activity is the same as that of a single substance. _{2) It} was found that the amount of ethylene added to the packaging material is higher than that of zeolite and the like, so that the packaging material is provided with ethylene adsorption, gas permeability and antibacterial properties, and thus becomes a freshness-maintaining packaging agent. Dissolve hinokitiol in water or solvent, impregnate this with finely ground hydroxyapatite obtained by natural or synthetic method to about 0.02 to 30 μm, and then wash with water or solvent to support it on hydroxyapatite. After washing away the hinokitiol which is not present, it is dried and powdered. Alternatively, it has been found that hinokitiol can be easily supported on hydroxyapatite by supporting hinokitiol on hydroxyapatite by coexisting with hinokitiol during wet synthesis of hydroxyapatite by a conventional method. The amount of hinokitiol supported on hydroxyapatite can be arbitrarily selected depending on the concentration and purpose of use of hydroxyapatite, etc., but the amount of hinokitiol supported on hydroxyapatite is 10% or less, and antibacterial activity is obtained. In order to require 0.1% or more.
The obtained hinokitiol-supporting hydroxyapatite antibacterial material exhibits sufficient freshness-retaining ability by being added to packaging materials such as polyethylene, polypropylene, polyvinylidene chloride and polyvinyl chloride in an amount of 50% or less, preferably 1 to 20%.

The present invention will be specifically described below with reference to examples.

Example 1) 1.5 g of hinokitiol is dissolved in 500 ml of ethanol, 100 g of hydroxyapatite is added, and the mixture is stirred. The product was thoroughly washed with ethanol and distilled water, dried and pulverized to obtain antibacterial hydroxyapatite powder carrying 1.5% of hinokitiol.

The control is hydroxyapatite powder that does not carry hinokitiol.

The antibacterial activity of the obtained powder against Escherichia coli was as follows.

After 0 hours 24 hours Powder 4.0 × 10 ⁵ 10 or less Control 1.0 × 10 ¹⁰ 2.3 × 10 ¹² Example 2) 10% of hydroxyapatite antibacterial material supporting 1.5% of hinokitiol was ingested, and a polyethylene film of 0.03 mm thickness (No. 1) was created. The film was formed into a bag, a banana was placed therein, and the film was sealed and placed at room temperature. In addition, for comparison, the thickness with 10% hydroxyapatite
0.03mm polyethylene film (No.2) and thickness 0.03mm
A polyethylene film (No. 3) was prepared and the same experiment was conducted. The results are shown in the table.

From this test result, it can be seen that the film to which the hydroxyapatite antibacterial material was added exhibited an excellent freshness-keeping effect as compared with the film to which nothing was added and the film to which only hydroxyapatite was added.

Reference Example 1) Ceramic powder (hydroxyapatite, calcium monohydrogen phosphate,
Calcium dihydrogen phosphate, tricalcium phosphate, calcium pyrophosphate, zeolite) is added and stirred to impregnate hinokitiol, then washed well with ethanol and distilled water to wash away hinokitiol not supported on the ceramic powder. By a simple operation, hinokitiol was supported on these ceramic powders, and the supported amount was measured to obtain the maximum supported amount. The results are shown in Table 1.

(Effect of the invention) Not only a hydroxyapatite antibacterial material is used as a freshness-keeping material in a packaging material, but by adding it into a water-absorbent resin or the like, a freshness-keeping material that is sealed with food and is a safe freshness-keeping material, It can be used for many things such as disposable diapers that are safe and require antibacterial properties.

Claims (1)

[Claims] 1. A freshness-retaining agent for foods, which comprises a hydroxyapatite antibacterial material supporting hinokitiol.