JPH0677515B2 - Food preservatives and food preservation methods - Google Patents

Description

TECHNICAL FIELD The present invention relates to a food preservative in which protamine extracted and purified from the testis of seafood and a specific carbon salt are used in combination, and a method for preserving food using the same. .

[Conventional technology]

Due to the development of the distribution system in recent years, cooked foods such as tofu, konjac, Tokotenten, wild vegetables, bamboo shoots, etc. that were once sold over the counter were put in a plastic container or bag with water or an aqueous solution. It is now sold in a simple package.

Since these foods contain a large amount of water, they are not easily spoiled, and they are usually distributed at a low temperature, and in some cases, the deterioration of foods can be prevented by taking measures such as daily distribution. As a method for improving the storability of such foods, a method of lowering the pH of the aqueous solution by adding an organic acid, a method of adding a large amount of sugar or salt to lower the water activity cannot be adopted because the flavor of the food itself is impaired.

In addition, the synthetic preservatives that are currently allowed to be used are limited in foods to which they are applied, and consumers do not have a good image of foods to which synthetic preservatives are added. Therefore, development of food preservatives centering on natural products is strongly desired.

Many of the natural substances have been reported to have a certain kind of antibacterial activity although they are weak, and some have already been marketed as commercial products. However, all of them are tastes derived from raw materials,
It has odor and color and is not always satisfactory.

[Problems to be Solved by the Invention]

Recently, attention has been paid to the antibacterial activity of protamine extracted and purified from salmon roe. Regarding the antibacterial activity of protamine, it has an antibacterial activity against bacteria, especially Gram-positive bacilli, and its antibacterial activity is influenced by the higher expression of the effect on the alkaline side of pH and the components in the medium, especially the protein. Things are already well known. However, most of the actual foods are weakly acidic, and since protein is present, protamine alone is not effective. Therefore, it is effective as a preservative in combination with various amino acids, organic acids, alcohols, food emulsifiers and others. Attempts have been made to raise it.

Therefore, the inventors of the present invention, judging from its storage state, are very perishable, but foods for which a particularly effective method cannot be taken so far, such as pack tofu, to name a few,
As a result of studying the method of storage, it was determined that protamine contained in the sperm nucleus of seafood might be effective.

However, while protamine shows remarkable antibacterial activity in experiments conducted in the laboratory paying close attention to microbial contamination, almost no antibacterial activity is observed in experiments conducted in actual food production. Most of the Shirako, which is a raw material for the extraction and purification of protamine, has been disposed of, and there is a strong demand for its advanced utilization as an unused resource.

Unlike other natural product type antibacterial agents, protamine is relatively tasteless and odorless and is very promising from this heaven, but in actual food systems most of them are weakly acidic and more or less protein Therefore, in order to develop the antibacterial activity of protamine, effective solutions to these two points must be considered.

[Means for Solving the Problems]

In order to use protamine as a preservative for foods, it is preferable that the protein does not coexist, or even if the protein coexists, the protein is already denatured by heating or another cooking method and does not act on protamine.

The inventors of the present invention think that there are no special cases other than the former in the actual food system regarding this matter, and as a result of diligent examination of the usage of the latter, hot pack tofu, konjac, Tokoten and other wild vegetables , As a form of distribution and sales such as that seen in boiled bamboo shoots, we focused on foods that contain cooked foods in water or an aqueous solution.

Another problem, that protamine has a low antibacterial activity in an acidic range, can be solved by adding an appropriate amount of sodium or potassium salt together with protamine to make the system alkaline.

It is already known that protamine is alkaline and its antibacterial activity is strengthened, but if it is added to ordinary foods at the time of food production, it will have an adverse effect on the physical properties of the food itself, so it was not considered to be actually done. .

In the method according to the present invention, protamine and the alkaline compound are simultaneously dissolved in water that wraps the outside of the food, and the antibacterial activity of protamine can be sufficiently expressed by keeping the food to be weakly alkaline so that the food itself is not affected.

Further, the present inventors have found that the presence of protamine in an alkaline system increases the antibacterial activity, and in addition to repeated experiments, the antibacterial activity of protamine dramatically increases in the presence of a specific alkaline compound.

The term protamine as used in the present invention is obtained from sardine such as salmon, masu, herring, mackerel, cod, squid, and scallop, and is usually insoluble in water as it is. May be. As for the manufacturing method, a commonly used method may be used.

The carbonate in the present invention means “potassium carbonate”, “sodium carbonate” and “sodium hydrogen carbonate”, but it is not limited to these and any salt may be used as long as it exhibits alkalinity when dissolved in water. The amount of carbonate added to 1 weight of protamine
0.01 to 3000 parts, preferably 0.05 to 600 parts is good.

The amount of protamine added to water as a preservative formulation is preferably 0.005 to 15 parts by weight, but is not limited to this concentration when it affects the flavor or other effects on food.

The food filled with the aqueous solution as used in the present invention means tofu, boiled bamboo shoots, boiled edible wild plants, konjac, heaven, etc., which are distributed and sold in the presence of water in a container. It is not limited to food only.

〔Example〕

 The details will be described in the following examples.

Example 1 The following experiment was conducted in a factory producing silken tofu.

A. Tofu manufactured in the usual process and hot-packed by adding tap water B. Tofu hot-packed after adding protamine hydrochloride 0.3% tap water solution in place of tap water.

C. pH 8.0 by dissolving trisodium phosphate instead of tap water
The one to which weak alkaline tap water solution adjusted to is added.

D. Dissolve sodium hydrogen carbonate instead of tap water to obtain a pH of 8.0
The one to which weak alkaline tap water solution adjusted to is added.

E. Protamine 0.3 Hot-pack tofu made by adding and dissolving a small amount of trisodium phosphate crystals in a tap water solution and adjusting the pH to 8.0, instead of tap water.

F. Protamine 0.3 Hot-pack tofu made by adding and dissolving a small amount of sodium hydrogencarbonate crystals in a tap water solution and adjusting the pH to 8.0, instead of tap water.

Eight tofu pieces produced under the above conditions were stored in a refrigerator (10 ° C.) and taken out daily, and the number of general viable bacteria was measured according to the Food Sanitation Law. The results are shown in Fig. 1.

Example 2 Bamboo shoots of about 2.5 to 3 kg are cut off diagonally and boiled with a sufficient amount of water to cover the bamboo shoots. At this time, add about 10% of rice bran. When boiled, let stand to cool. Next, the skin was peeled off, washed thoroughly with water, and then cut into pieces each weighing about 100 g for use in the following experiment.

A. 200 ml of tap water and one bamboo shoot (about 100 g) that had been cut were placed in a polypropylene bag, the upper air was evacuated, the mouth was closed with a rubber ring and heated in boiling water for 1 hour.

B. In the place of tap water, protamine hydrochloride 0.2% tap water solution was added and treated in the same manner.

C. Instead of tap water, aqueous sodium hydroxide solution (pH 8.
5) was added and processed in the same manner.

D. A tap water solution (pH 8.5) in which brackish water for Chinese noodles in which the ratio of potassium carbonate, sodium carbonate and sodium hydrogen carbonate was 11: 2 was dissolved in place of tap water was treated in the same manner.

E. Protamine 0.2% aqueous solution with a small amount of sodium hydroxide added and dissolved to adjust the pH to 8.5, and then treated in the same way as tap water instead of tap water.

F. Protamine 0.2% aqueous solution, a small amount of the brine used in D above was added to adjust the pH to 8.5, and the solution was added in place of tap water and treated in the same manner.

Under each of the above conditions, eight bamboo shoots were boiled and stored in a thermostat at 25 ° C, and they were sensory-evaluated daily with respect to the taste, color, odor, and deformation of the bamboo shoots. The results are shown in Table 1.

[Effects of the Invention] As described above, protamine, which cannot exhibit sufficient antibacterial activity in a complex food system by itself, is treated with "sodium carbonate".
Specific antibacterial enhancement was confirmed by combining with one or more of "potassium carbonate" and "sodium hydrogen carbonate". This not only leads to effective use of resources that were previously discarded, but also extends the shelf life of foods that were not previously stored effectively, which will benefit both producers and consumers. Is.

In particular, for foods such as tofu, boiled bamboo shoots, konjac, tokoten tempura, and boiled edible wild plants, it is possible to extend shelf life by distributing and selling them while immersed in an aqueous preservative solution.

[Brief description of drawings]

FIG. 1 is a chart showing the relationship between the general viable cell count and the storage period of the product of the present invention and the comparative product.

Claims (2)

[Claims] 1. A preservative for foods, which comprises protamine in combination with at least one of various carbonates such as potassium carbonate, sodium carbonate and sodium hydrogen carbonate. 2. A method for preserving foods, which is distributed and sold after being molded and packed together with the aqueous solution containing the preservative according to claim 1.