JP2681374B2 - Yeast or bacterial growth and growth inhibitor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a yeast or bacterial growth and growth inhibitor, and more particularly to a yeast or bacterial growth and growth inhibitor containing chitosan and ascorbic acid as active ingredients.

[Conventional technology]

Many synthetic products such as benzoic acid, sorbic acid, propionic acid, and salicylic acid are known as antibacterial agents, preservatives, and bactericides for foods and cosmetics, but these synthetic products are artificial and therefore safe. Sometimes caused problems.

In order to improve this point, recently, an antibacterial agent and a fungicide containing chitosan as an active ingredient, which is obtained by deacetylating chitin contained in the shells of crustaceans such as shrimp and crab, have been proposed. (Kaisho 59-46223, JP-A-62-83877).

However, such an antibacterial agent or bactericidal agent containing chitosan as a main component has an insufficient antibacterial effect and must be used in a large amount in order to exert the antibacterial effect.
Further, there is a defect that there is almost no inhibitory effect on growth and proliferation of yeast.

The present invention has been made in view of the above-mentioned circumstances of the prior art, the object of which is to show antibacterial activity at a low concentration, yet exert a remarkable growth and proliferation inhibitory effect not only on bacteria but also on yeast. The present invention provides a growth and growth inhibitor for yeast or bacteria.

[Means for solving the problem]

As a result of earnest studies on the growth and proliferation inhibitors of yeast or bacteria mainly composed of chitosan, the present inventors have found that combining ascorbic acid with chitosan exerts an excellent synergistic effect, and completes the present invention. Came to.

That is, the yeast or bacterial growth and growth inhibitor of the present invention is characterized by using chitosan and ascorbic acid as active ingredients.

As the chitosan used in the present invention, conventionally known ones can be applied, and examples thereof include commercially available chitin and chitosan obtained by deacetylating naturally occurring chitin by a conventional method. As an example of the latter, for example, the chitin obtained by decalcifying and deproteinizing crab shells is immersed in an aqueous sodium hydroxide solution having a concentration of 40 to 50%, reacted at 50 to 130 ° C, and then alkali is removed. Then, there are flakes obtained by washing with water and drying, or powdery chitosan which has been further subjected to a pulverization process.

Chitosan has a low deacetylation rate of at least 70% because it has poor solubility when the deacetylation rate is less than 70%.
It is desirable that this is the case.

Further, in the present invention, when the molecular weight of chitosan is small, the effect of suppressing the growth and proliferation of bacteria and yeast becomes small. Therefore, the viscosity of a 1% aqueous solution of chitosan at 25 ° C. (viscosity by B-type viscometer) is preferably 50 cp. Is 100 cp or more.

As ascorbic acid, L-ascorbic acid and isoascorbic acid are preferably used. The form of use of this ascorbic acid is not particularly limited, but it is desirable to use it as a powder or as an aqueous solution. The mixing ratio of chitosan and ascorbic acid is 1: 0.9 to 3.0 by weight, preferably
It is 1: 1.0 to 2.0. These components are essential components, and it is possible to further mix other components.

The yeast or bacterial growth and growth inhibitor of the present invention exerts its effectiveness against various yeasts and bacteria, and specific examples thereof will be shown below.

[Example of yeast]

Candida ambicans, Hansenula sveveolence, Debaryomyces hansenii, Saccharomyces cerevisiae, Saccharomyces bailey [Examples of bacteria] Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Streptococcus faecalis, Streptococcus mutans, Escherichia, Escherichia Pseudomonas aeruginosa, Proteus vulgaris, Salmonella enteritidis, Bacteroides gingivalius, Bribacterium polymorphum,
Pitirosporum ovur, Propionibacterium acnes, leuconostoc mesenterioides In the present invention, the use form of the mixture of chitosan and ascorbic acid depends on the application, powder, aqueous solution or alcohol such as ethanol or isopropyl alcohol. It may be in various forms such as an aqueous solution containing, and if necessary, other components such as a synthetic antibacterial agent such as benzoic acid and sorbic acid may be added.

In addition, chitosan concentration is 0.00
It is desirable to adjust the content to be 5% to 3% by weight, more preferably 0.01% to 1.0% by weight.

〔The invention's effect〕

The yeast or bacterial growth and growth inhibitor of the present invention has chitosan and ascorbic acid as active ingredients,
Compared with chitosan alone or a combination of chitosan and an acid such as acetic acid or lactic acid, its antibacterial action is exhibited at a low concentration, and moreover, it exerts a remarkable growth and proliferation inhibitory action not only on bacteria but also on yeast. Therefore, the yeast or bacterial growth and growth inhibitor of the present invention is, for example, shrimp,
Kai, antibacterial agents for marine products such as fish fillets, preservatives for kneaded products such as sardines and kamaboko, disinfectants for vegetables and fruits, sterilization of food processing facilities such as meat and seafood, disinfectants, shampoos, rinses, etc. Anti-dandruff agent, remedy for candidiasis, etc.
It is preferably used in a wide range of fields such as food, medicine, and cosmetics.

〔Example〕

Next, the present invention will be described in more detail by way of examples.
The parts and% shown below are based on weight unless otherwise specified.

Example 1 Powdered chitosan (2 parts of chitosan was added to a 1% aqueous solution of acetic acid 19
Dissolved in 8 parts, viscosity measured at 25 ° C: 1200 cp, degree of deacetylation 85%) 1.3 parts of L-ascorbic acid was added to 1 part, and 1.15%
The concentration of chitosan L-ascorbic acid aqueous solution was adjusted.
The pH of the chitosan solution is adjusted to 6.0 ~ with a 10% caustic soda solution.
After adjusting to 6.5, it was sterilized using a 0.45μ filter, and then double-diluted with autoclave-sterilized Mueller Hinton medium (manufactured by Difko Laboratories).
A medium containing the concentration of chitosan shown in 1 was prepared. This medium was pre-pre-cultured at 25 ° C for 48 hours and pre-cultured.
The yeast shown in 1 was planted and cultivated at 25 ° C. for 48 hours, generation of turbidity was observed, and those with turbidity were designated as (+), and those without turbidity were designated as (−). Those with turbidity indicate the growth of yeast, and those without turbidity indicate that the yeast did not grow. The results are shown in Table 1.

Comparative Example 1 To 1 part of chitosan used in Example 1 was added 1 part of acetic acid.
A 5% strength chitosan / acetic acid aqueous solution was prepared. Hereinafter, the same procedure as in Example 1 was performed. The results are shown in Table 1.

Comparative Example 2 1.3 parts of lactic acid was added to 1 part of chitosan used in Example 1.
A 0.5% aqueous chitosan / lactic acid solution was prepared. The results are shown in Table 1. Hereinafter, the same procedure as in Example 1 was performed.

It can be seen from Table 1 that the mixture of chitosan and ascorbic acid has an excellent inhibitory effect on the growth and proliferation of yeast.

Example 2 The 1.15% concentration of chitosan / L-ascorbic acid aqueous solution used in Example 1 was adjusted to pH 6.0-with 10% caustic soda aqueous solution.
After adjusting to 6.5, it was sterilized using a 0.45μ filter, then autoclaved, and double-diluted with Mueller Hinton medium (manufactured by Difko Laboratories) to adjust the medium having different chitosan concentrations. This medium was previously 37 ℃
The pre-preculture and preculture were carried out for 24 hours, and the bacteria shown in Table 2 were inoculated, followed by cultivation at 37 ° C. for 24 hours to determine the minimum inhibitory concentration. Table 2 shows the results.

Comparative Example 3 The minimum inhibitory concentration was determined in the same manner as in Example 2 except that the chitosan / L-ascorbic acid aqueous solution used in Example 2 was replaced with the chitosan / acetic acid aqueous solution. Table-Results
It is shown in FIG.

Comparative Example 4 The minimum inhibitory concentration was obtained in the same manner as in Example 2 except that L-ascorbic acid was used instead of the chitosan / L-ascorbic acid aqueous solution used in Example 2. Table 2 shows the results.

Example 3 0.46% chitosan / L-ascorbic acid aqueous solution (weight ratio of chitosan: L-ascorbic acid = 1.0: 1.3) was soaked with red sprout, red onion, green onion and tuna for 1 minute, and then each was taken out and tray packed. Then, the cells were stored at a temperature of 5 to 10 ° C and examined for the number of viable bacteria and the presence of E. coli. The general viable cell count is based on the standard agar culture method. For E. coli, the EC test method is used.
The general viable cell count is shown per 1 g of sample and E. coli is shown per 0.1 g of sample. Table 3 shows these results.

Comparative Example 5 The same preservation was performed without the treatment with the chitosanated-ascorbic acid aqueous solution of Example 3. The results for the general viable cell count and E. coli are also shown in Table 3 together.

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Claims (2)

(57) [Claims] 1. A growth or proliferation inhibitor for yeast or bacteria, which comprises chitosan and ascorbic acid as active ingredients. 2. The yeast or bacterial growth and proliferation inhibitor according to claim 1, wherein the weight ratio of chitosan to ascorbic acid is 1: 0.9 to 3.0.