JPH0928361A - Control over lactic acid bacteria - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress lactic acids which have been causative microorganisms for recent great deterioration of foods with a safe food ingredient or a safe food additive. SOLUTION: Citric acid or an edible salts thereof and one or more pyrophosphates, polyphosphates, metaphosphates or ultraphosphates are used in combination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling or suppressing lactic acid bacteria mainly in the field of food and drink.

[0002]

BACKGROUND OF THE INVENTION Lactic acid bacteria are fermented products such as a wide range of natural animals and plants, humans and other animals and poultry, digestive tract, excrements, foods, edible muscles, milk, dairy products, pickles, etc. , Such as seasoned foods such as miso and soy sauce are very widely distributed,
Its main characteristic is that it makes lactic acid from sugar, and it grows in the presence of air, but it has the characteristic of growing better especially in the absence of air, that is, oxygen. A type that produces only lactic acid from sugar is called a homo-type lactic acid bacterium, and a type that produces carbonic acid gas and, in some cases, acetic acid in addition to making lactic acid from sugar is called a hetero-type lactic acid bacterium.

Lactic acid bacteria are used for the production of many fermented products due to the property of producing lactic acid from sugar. Fermented milk, yogurt, cheese, many pickles, fermented sausages, many kinds of accustomed sushi, etc. are lactic acid bacteria. It is a typical food product produced by using, while imparting a characteristic flavor to these foods, it sterilizes or bactericidal spoilage bacteria and food poisoning bacteria in these foods, and imparts long-term storage stability. ing.

[0004] Further, lactic acid bacteria suppress harmful bacteria such as spoilage bacteria in the intestinal tract to bring about an intestinal regulating action, so that they are useful as foods and drinks containing lactic acid bacteria, or as pharmaceutical tablets and tablets. Is widely used as an oral ingestion.

However, lactic acid bacteria contaminate a large number of foods and drinks due to its too wide range of life, grow inside and on the surface of the foods, and more or less produced lactic acid impairs the flavor of the foods and drinks, thus reducing its commercial value. When the number of live bacteria in these foods and drinks is lowered, and the number of live bacteria in those foods and drinks is measured, a significantly large number of live bacteria is measured, even though the food does not seem to be so spoiled. Will not be allowed to be distributed as food. Not only that, when a hetero-type lactic acid bacterium grows in food, carbon dioxide and the like are produced in addition to lactic acid, so that in a packaged food, the inside of the package is filled with gas, and the package expands, which is called swelling. It leads to the typical corruption.

[0006] The contamination and spoilage of foods by such lactic acid bacteria have tended to increase significantly more recently. This is largely due to recent changes in food and drink manufacturing methods, packaging methods, storage and distribution temperatures, and changes in food additives used. That is, recent foods and drinks significantly reduce the salt concentration, which has been conventionally used at a high concentration, in response to consumers 'and consumers' preference for natural foods and health, for example, squid salt is used at 15 to 17%. About 3 to 5% of what was used, and tsukewan pickles with soy sauce pickled 12
What used to be 13 to 13% is reduced to about 4 to 7%. This level of salt concentration is more suitable for the growth of lactic acid bacteria.

[0007] As for the progress of packaging methods, although packaging methods such as vacuum packaging and gas displacement packaging have been developed for foods,
These packaging methods reduce the air or oxygen concentration inside the package, or package the food in an almost oxygen-free state, and for lactic acid bacteria that grow better under anaerobic conditions than under aerobic conditions. Rather, they are supposed to provide conditions that are convenient for growth.

Recently, foods have been often stored and distributed at a low temperature of 10 ° C. or lower, especially at a temperature of about 5 ° C. The storage and distribution at this temperature is because the growth of ordinary mesophilic bacteria is very suppressed, and almost no growth or only a very slow growth rate can be achieved.
Maintenance of hygienic condition of food or progress of spoilage is suppressed very efficiently. However, when the food is maintained at such a low temperature, microorganisms such as bacteria and yeast, which prefer the low temperature, gradually grow. These are, for example, Yersinia enterocolitica (Yersini) as food poisoning bacteria.
a enterocolitica), Listeria monocytogenes (Listeria monocytogenes)
nes), Clostridium botulinum (Clos)
Tritium botulinum E type bacteria, etc., and some other non-protein-degrading Clostridium botulinum (Clostridium botulum)
inum) fungus is also included. On the other hand, as a spoilage or food spoilage microorganism that prefers low temperature, Pseudomonas (Pseudo)
-Monas bacterium, Flavobacterium (Flav)
bacteria, Acinetobacter (A)
Along with bacteria belonging to the genus Cinetobacterium, yeast and some lactic acid bacteria that prefer low temperature grow.

[0009] Further, recent foods are, due to their natural orientation and health orientation, avoided the use of preservatives and bactericides of chemically synthesized products, and have natural or near-natural properties such as organic acids and amino acids, Alternatively, fatty acids and their esters, and plant seeds and essential oils and extracts tend to be used for food preservation, but these ingredients generally have weak antibacterial properties against lactic acid bacteria, so rather than using them, This causes a situation in which lactic acid bacteria selectively remain in foods. For example, acetic acid or sodium acetate is most widely used for the preservation of food, but in MRS medium, which is a typical medium for culturing lactic acid bacteria, sodium acetate is the main component of lactic acid bacterium culture. It is added as one, which guarantees the vigorous growth of lactic acid bacteria. When sodium acetate is used in food, the growth of lactic acid bacteria is promoted. A similar example is glycine, which is used in many foods because it is effective in suppressing the aerobic spore-forming bacterium, Bacillus, but glycine is effective against lactic acid bacteria. It has no antibacterial action at all, and as a result, bacteria other than lactic acid bacteria are suppressed by glycine, and as a result, lactic acid bacteria remain selectively.

[0010]

As described above, in foods and drinks, the deterioration due to lactic acid bacteria has become particularly remarkable recently, and in the distribution and storage of many foods and drinks, lactic acid bacteria are used. How to prevent the deterioration due to is becoming a big issue. However, it has gradually become clear that suppression of lactic acid bacteria is extremely difficult.

Lactic acid bacterium is a bacterium that is weak against heating, and if it can be heated appropriately, it can be relatively easily treated by aseptic packaging after heating or by applying heat from outside the packaging after packaging. Can be killed. However, aseptic packaging requires that all of the packaging room, the person packaging, the environment equipment and atmosphere, and the packaging material itself be kept aseptic. However, unless it is a food and drink product with a considerably high added value, it usually cannot be realized in terms of cost. In addition, heating after packaging must not contain gas including air in the inside of the package, and requires a vacuum packaging machine and a packaging material suitable for it. This also requires a considerable cost and is difficult to use unless it is a food or drink of high added value. In addition, there are foods that can be heated after packaging and foods that are not so preferable. For example, ham-like foods are discolored by heating, and their shapes are shrunk and deformed.

[0012] In order to suppress lactic acid bacteria, it has been attempted to suppress them by various chemical components by natural products or chemical synthesis, but lactic acid bacteria are resistant to most chemical substances. For example, although organic acids are used for food preservation and suppression of food poisoning bacterial fields, acetic acid, which is the most widely used, has almost no effect as shown above, and propionic acid and lactic acid following acetic acid are also effective in some cases. Occasionally, we need very large amounts, up to 2-3%. Glycine, which is a commonly used shelf life improver, is completely ineffective against lactic acid bacteria as described above. The hop component of a natural product exhibits antibacterial properties against lactic acid bacteria, but in foods, the antibacterial activity is impaired by the food component, so that it is virtually impossible to expect an effect. While the same natural white matter protein is very effective on medium, it is virtually ineffective in protein-rich foods such as sausages and kamaboko. Glycerin fatty acid esters may also be effective on the medium, but they are hardly effective in protein-rich foods.

Many bacteria, in the presence of high concentrations of salt,
Although they die or cannot grow, lactic acid bacteria grow better in the presence of salt to some extent than in the absence of salt, and when general bacteria are difficult to grow, they grow preferentially first. Alcohol is usually used as a disinfectant, but lactic acid bacteria
It is very resistant compared to ordinary bacteria and requires 3 to 4 times the alcohol concentration at which general bacteria are killed.

As described above, the deterioration of food and drink due to lactic acid bacteria
Although it is not dangerous like the change in food due to the growth of food poisoning bacteria, it loses the commercial value of food and drink and wastes food and drink, so it is necessary to establish some kind of prevention method in any case.

[0015]

According to the present invention, the presence of citric acid or citrate ion and polymerized phosphate significantly suppresses the growth of lactic acid bacteria, and its action is under the condition that the pH is neutral or alkaline. The present invention has been completed by discovering that it is particularly effective in.

It is generally accepted that organic acids have the action of sterilizing microorganisms and bacteriostatically treating them. It is said that the effect is usually obtained by the action of three kinds of organic acids, and they are (1) p
The H is reduced, which causes microbes to be killed or unable to grow. (2) When the organic acid enters the inside of the microbial cell, the pH inside the microorganism is lowered and the microorganism cannot grow. It is said that the non-dissociated molecule of the organic acid is more likely to enter the microbial cell, and therefore, the weak acid such as acetic acid has a higher proportion of the non-dissociated molecule at a constant pH value, and is therefore considered to have stronger antibacterial properties. (3) Each of the organic acids has its own antibacterial action, thereby exhibiting a characteristic antibacterial action. For example, acetic acid has a broad antibacterial action on bacteria, mold and yeast except for lactic acid bacteria, while lactic acid has a broad antibacterial action on bacteria, but has almost no antibacterial action on fungi and yeast. The antibacterial action of organic acids is said to be a comprehensive manifestation of the above three actions.

In general, the antibacterial action of organic acids is
When the pH of the medium is low, the concentration of non-dissociated acid increases,
Therefore, it is said that the rate of entry of organic acid into microbial cells increases, and it becomes effective at a low concentration, that is, it works well, and in fact, even in the reports of antibacterial action of organic acid in all academic journals, it is obvious It is mentioned as the property of the antibacterial action of organic acids.

Citric acid is one of the organic acids, and it has been considered that its antibacterial action exhibits properties similar to those of ordinary organic acids. In other words, its antibacterial effect is that if citric acid is added as it is to a medium or foods, the pH is lowered and microorganisms are suppressed. In addition, in a medium or food having a low pH, the proportion of non-dissociated molecules is increased, and thus a strong antibacterial action is obtained. In fact, the action of citric acid on ordinary microorganisms is as described above.

However, the antibacterial action of citric acid against ordinary bacteria and lactic acid bacteria is shown on ordinary agar medium at pH 4.
When examined in the range of 0 to pH 7.0, it was found that citric acid exhibited a completely unexpected antibacterial action, especially against lactic acid bacteria. That is, citric acid shows almost no antibacterial action against Gram-negative bacteria regardless of pH. For Gram-positive bacteria other than lactic acid bacteria, the antibacterial activity is affected by pH and is 4.0 to 5.0.
In such a low pH range, a relatively strong antibacterial action is exhibited, but in a neutral pH range such as pH 7.0, almost no antibacterial action is exhibited. On the other hand, for lactic acid bacteria, it showed growth inhibition to all lactic acid bacteria at a pH of about 1 to 2% in the neutral range, and showed much antibacterial action in the acidic range of pH 4.0 to 5.0. It was the result of saying no.

In order to further confirm this action, the action of citric acid was examined in the range of pH 5.0 to pH 9.0 against 21 field-isolated lactic acid bacteria, and this tendency was observed for field isolates. However, in the same manner, citric acid inhibits the growth of lactic acid bacteria at 1.0% to 2.0% in neutral or alkaline, but the effect becomes weaker when it becomes acidic. It was also found that, more interestingly, the presence of sodium chloride in the medium clearly enhanced the inhibitory effect of citric acid on lactic acid bacteria at a concentration of about 0.5% or more.

The action of citric acid on lactic acid bacteria is contrary to the common knowledge of the antibacterial action of ordinary organic acids on microorganisms, and the action of citric acid on lactic acid bacteria is, for example, the chelating action of citric acid on metals. Things may be involved, but so far the mechanism of action is unclear. However, since such an action of citric acid against lactic acid bacteria is particularly effective in neutral or alkaline, it has an advantage that it can be used without imparting a sour taste peculiar to citric acid to foods, and its range of use is very wide.

Further, the action of citric acid and citrate on lactic acid bacteria, when used in combination with polymerized phosphates,
It became clear that it became significantly stronger and the required amount was lower. Although the inhibition of lactic acid bacteria by citric acid or its salts is effective, the amount required for the inhibition of lactic acid bacteria is 1 to 2% by itself, and although it has little effect on the quality and flavor of food, it is economical. Even lower amounts are desirable, and it is very useful that the combination with such polymerized phosphates increases the effect and reduces the amount used.

As a preliminary experiment for confirming the effect, first, the effect of citric acid against general bacteria and lactic acid bacteria on the medium and the minimum inhibitory concentration of acetic acid for comparison and the influence of pH on it were examined. As 1,
It carried out as follows. Add citric acid or acetic acid to standard agar medium, adjust the pH with caustic soda,
The medium was used from pH 4.0 to pH 7.0. Concentrations of citric acid and acetic acid in the medium are set from 4.0 at maximum to successively lower concentrations by 2-fold dilution, and the lowest concentration is set at 0.
It was set to 015%. The medium was sterilized in an autoclave, and after the agar had sufficiently solidified, it was preliminarily brothed at 37 ° C for 24 hours.
Inoculate 10 strains of lactic acid bacteria and 10 strains of general bacteria that were cultured for a time with a micro planter manufactured by Toyo Sokki Co., Ltd.
After culturing at 37 ° C for 48 hours, the inhibitory concentration was determined by the presence or absence of growth. This experiment is for knowing the property of the lactic acid bacterium suppressing effect of citric acid alone, and the results are as shown in Table 1.

[0023]

[Table 1]

As is clear from Table 1, the action of citric acid on lactic acid bacteria is very unique in contrast to acetic acid, and was stronger in the neutral range than in the low acidic pH range. However, against bacteria other than lactic acid bacteria, it also showed an antibacterial action which became stronger on the acidic side, and this tendency was observed especially in Gram-positive bacteria. Also, it had almost no effect on Gram-negative bacteria. Acetic acid, on the other hand, exhibits the general action properties of common organic acids, showing an antibacterial action against Gram positive and negative bacteria, which is strong on the acidic side and weak on the alkaline side. In addition, the experiment was carried out by neutralizing citric acid with caustic soda, but as is clear from the results, citric acid is mostly dissociated into citrate ions at neutral, and it is effective in the dissociated state. This means that it may be used in the form of salts such as sodium and potassium citrate. Therefore, in the present invention, it is clear that the use of citric acid may use edible salts of citric acid.

Furthermore, in order to confirm the nature of the effect of citric acid, in order to see the effect of citric acid in neutrality or alkalinity on a large number of lactic acid bacteria isolated from foods, etc., and at the same time to investigate the effect of air, Experiment 2 was tested on medium under both aerobic and anaerobic conditions. The medium was an ordinary agar medium under the same conditions as in Experiment 1 above, and the test bacteria were similarly cultured in broth for 24 hours and inoculated with a microplanter. The method of adding citric acid to the medium and adjusting the pH was the same as in Experiment 1, except that the pH of the medium was changed from pH 5.0 to pH 9.0. The medium was autoclaved under high pressure. The culture temperature of the bacterium was 27 ° C., which was suitable for lactic acid bacteria, and the effect was determined depending on the presence or absence of growth after 5 days of culture. The results are shown in Table 2.

[0025]

[Table 2]

As can be seen from Table 2, citric acid exerts the same effect on lactic acid bacteria of field strains isolated from foods and the like, and the pH region is more neutral or alkaline than the acidic region. It was found to effectively suppress lactic acid bacteria.

[0027]

Example 1 For the action of citric acid on lactic acid bacteria,
In order to examine the effect of the polymerized phosphates, under the same conditions as in Experiment 2, first, 0.5% of each polymerized phosphate was sterilized by filtration sterilization and then added to the medium, and the various concentrations were quenched. On a standard agar medium containing acid at pH 7.2,
Lactic acid bacteria isolated from the field used in Experiment 2 above were inoculated with a microplanter, cultured at 27 ° C for 5 days, and the antibacterial action was judged by the presence or absence of growth. The results are shown in Table 3.

[0028]

[Table 3]

As is clear from these results, all the polymerized phosphates are effective, but among the polymerized phosphates, sodium tripolyphosphate is more effective than sodium pyrophosphate, and further sodium metaphosphate is used. Is the most effective.

[Example 2] In order to examine the difference in effect depending on the type and concentration of polymerized phosphates, sodium pyrophosphate, potassium pyrophosphate, sodium hexametaphosphate, potassium pyrophosphate and sodium ultraphosphate were added at 0.25% and 0.5%, respectively. Was sterilized by filtration in the same manner as in Example 1, and separately added to a standard agar medium of pH 7.2 that had been sterilized in advance in an autoclave containing various concentrations of citric acid, and mainly the same field isolate as in Example 1 was added. The lactic acid bacterium strain was inoculated by microplan, and 27
The effect was judged by the presence or absence of growth after culturing at ° C for 5 days. The results are shown in Table 4.

[0030]

[Table 4] As is clear from Table 4, among the polymerized phosphates, the effect tends to be unclear at a concentration of 0.25% or less for pyrophosphate, but clearly for sodium hexametaphosphate and sodium ultraphosphate. It can be seen that a concentration of 0.25% or less is also effective. In fact, when using these phosphates in foods, use them in the range of 0.05 to 0.5%, usually 0.2 to 0.3%.
At these concentrations, the synergistic effect with citric acid according to the invention is expected in each case, although the degree of use is most frequent. The scope of the present invention is that in each of the phosphates, at a concentration at which synergism with citric acid is observed,
Each is the applicable concentration range.

[0031]

[Example 3] Pork minced meat 2 kg, pork fat 0.2 kg,
Salt 40g, potato starch 50g, sodium nitrite 45
0 mg, sodium ascorbate 2.5 g, ice water 10
A meat slurry for sausage having a basic composition of 0 g and 20 g of the spice mixture was prepared in 3 sections. The first ward was used as a control ward without adding anything other than the basic composition. The second group was a comparative group in which 1% (25 g) of glycine, which has little effect on lactic acid bacteria but is widely effective on general bacteria, was added. In the third ward, glycine 1% (2
5 g) and a 1: 1 mixture of sodium pyrophosphate and sodium tripolyphosphate were added at 0.3% (7.5 g) to give a comparative section. In the fourth ward, glycine 1% (2
5 g), 0.3% of a 1: 1 mixture of sodium pyrophosphate and sodium tripolyphosphate, and 1% (25 g) of sodium citrate were added to the invention group. Each of these plots was mixed with a silent cutter for 2 minutes, and ice water and potato starch were mixed in the last stage, and then mixed for 1 minute,
Slurry for sausage, fill pork intestine, heat in hot water at 75 ° C for 17 minutes, then cool in a clean room,
It was vacuum-packed and stored at 10 ° C., and the number of general viable bacteria, the number of lactic acid bacteria, and the number of coliform bacteria were measured. The results are shown in Table 5.

[0032]

[Table 5]

[0033]

[Example 4] Strong powder 1 kg, water 120 g, kansui powder 1
The basic composition in which 0 g was added, 1st section: 5 g of salt, 2nd section: 5 g of sodium acetate, 3rd section: 5 g of sodium acetate, 8 sodium citrate
g, 4th ward: sodium acetate 5 g, sodium citrate 8
g, sodium pyrophosphate 2g, sodium hexametaphosphate 2g, mixed well, and then made noodle strings with a small noodle making machine, boiled in boiling water for 3.5 minutes, then water-cooled in cooling water, drained polyethylene bag Put it in a container and seal it, prepare 15 bags of noodles per test zone, store it in a thermostat at 25 ° C, measure the number of aerobic bacteria, mold, lactic acid bacteria and pH of the noodles and store each zone. Sex was compared. Table 6 shows the results.
It was shown to.

[0034]

[Table 6]

[0035]

[Example 5] A packaged fish paste was produced from salted frozen surimi as a raw material. For the salted frozen surimi, a commercially available product was purchased, and 3 kg of starch and 1 glutamic acid soda were added to 5 kg of frozen surimi.
%, Ice water 10% as a basic composition, and various additives related to the present invention were added thereto to produce the following Kamaboko for each test section. 1st ward: no addition 2nd ward: glycine 1% addition 3rd ward: glycine 1%, sodium citrate 2% addition 4th ward: glycine 1%, sodium citrate 1.0%,
Add sodium pyrophosphate 0.2%, sodium hexametaphosphate 0.2% Fifth section: Glycine 1%, sodium citrate 0.5%,
Sodium pyrophosphate 0.2% and sodium ultraphosphate 0.2% were added. The surimi of each of the above formulations was put into a sufficiently cooled silent cutter except ice water and starch, and mixed by cutting for about 5 minutes. Next, starch and ice water were added, and the mixture was further cut and mixed for 5 minutes. This was molded on a plate by a molding machine, immediately steamed in steam for 30 minutes to obtain steamed kamaboko, which was immediately vacuum-packed in a sterile clean room. This kamaboko was stored in a thermostatic chamber at 20 ° C., and swelling inside the kamaboko package, formation of spots, separation of a viscous liquid, and measurement of the number of lactic acid bacteria were carried out. The results are shown in Table 7.

[0036]

[Table 7]

[0037]

The effect of the present invention is that citric acid or an edible salt of citric acid and polymerized phosphates are used in combination, whereby citric acid or a salt thereof at a relatively low concentration effectively causes It is clearly recognized that the growth is suppressed or regulated, and its action depends on the type of phosphate, and with pyrophosphate, at normal concentrations,
Triphosphate is a little stronger than pyrophosphate,
Hexametaphosphate and ultraphosphate effectively suppress lactic acid bacteria when used in combination from a significantly low concentration. It was revealed that this action effectively suppresses the growth of lactic acid bacteria even in foods.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // A23L 1/317 A23L 1/317 A

Claims (2)

[Claims] 1. A method for suppressing lactic acid bacteria by using citric acid or an edible salt of citric acid in combination with one or more polymeric phosphates. 2. Polymerized phosphate, sodium and potassium pyrophosphate, sodium and potassium acid pyrophosphate, sodium and potassium tripolyphosphate,
The method for controlling lactic acid bacteria according to claim 1, which is sodium and potassium metaphosphate and sodium and potassium ultraphosphate.