JP2018057338A - Heat resistance reducing agent of bacterial spore, germination and growth method of bacterial spore - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for reducing heat resistance of pore at pH originally obtained by foods for heat resistant spore forming bacterial and a method for enhancing maintainability of foods using the same.SOLUTION: A mixture of one or more kind of linear phosphoric acid represented by the general formula (HPO)n, where n represents an integer of 3 to 800, and a heat resistance reducing agent of bacterial spore containing glycine and/or DL-alanine as active ingredients are added to target foods and germination and growth of the bacterial spore in the foods are suppressed by a heating treatment at 60°C for 5 min. or longer.SELECTED DRAWING: None

Description

  The present invention reduces the heat resistance of bacterial spores mixed in food, and is used for the production of foods that are functionally good and have excellent storage stability, and a method for suppressing germination and growth of bacterial spores. It is about.

  Ingredients such as agricultural, livestock and fishery products and cereals are manufactured and processed into food, which is stored, distributed and consumed. During these processes, contamination of food by microorganisms occurs. In particular, when there is concern about contamination of bacteria that form highly heat-resistant spores such as Bacillus bacteria or Clostridium bacteria, it is necessary to perform heat sterilization treatment that is harsher than general bacteria, yeasts and molds. In order to completely inactivate, autoclave treatment at 121 ° C. for 15 minutes or more, or dry heat treatment at 180 ° C. for 30 minutes or more is required.

  However, when such high-temperature treatment is performed, the original texture and flavor of the food are impaired, and thus heat treatment within the acceptable range of taste and bacteriostatic agent are often used in combination.

  The bacteriostatic agent slows the growth rate of microorganisms, but in order to suppress the growth of spore-forming bacteria, a component that suppresses germination of spores may be added.

  Examples of components that suppress spore germination include D-alanine (Non-patent Document 1), alcohol (Non-patent Document 2), organic acids (such as fatty acids) (non-patented) as germination inhibitors for Bacillus subtilis spores. Document 3) is known.

  Furthermore, it is known that acetic acid, citric acid, malic acid or lactic acid is effective in the acidic range of pH 4.2 to 4.6 as an active ingredient of germination growth inhibitor against Bacillus genus and Clostridium spore (patent) Reference 1).

JP 2020-110321

Y. Yasuda & K. Tochikuba: Microbiol. Immunol., 29, 229 (1985) Y. Yasuda-Yasaki et al .: J. Bacteriol., 136, 484 (1982) Y. Yasuda et al .: J. Med. Chem., 25, 315 (1982)

  However, the above-mentioned conventional technology has insufficient germination inhibiting effects such as D-alanine, and furthermore, in the pH range of pH 4.2 to 4.6, the acidity of acetic acid and citric acid is given, and the original taste of food There was a problem that damaged.

  Therefore, an object of the present invention is to provide a composition that lowers the heat resistance of spores at the original pH of food against heat-resistant spore-forming bacteria, and a method for improving the preservability of food using the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that a preparation containing metaphosphoric acid having a phosphorus number of 40 to 300 and glycine and / or DL-alanine is resistant to heat-resistant bacterial spores. The inventors have found that the present invention is lowered, and have completed the present invention.

  That is, the present invention provides the following general formula:

  The present invention provides a heat-reducing agent for bacterial spores, comprising as an active ingredient metaphosphoric acid composed of one or a mixture of two or more of linear phosphoric acid represented by glycine and / or DL-alanine. is there.

  The present invention also provides a method for inhibiting germination / growth of bacterial spores, comprising the step of adding the heat resistance reducing agent and the step of performing a heat treatment at 60 ° C. for 5 minutes or more.

  According to the present invention, the pH is not limited, the effect of reducing the heat resistance of bacterial spores can be exhibited at the pH of the target food, and it is not necessary to adjust the pH of the food to acidic or alkaline. The original taste and flavor are not impaired.

  Moreover, the combined use with glycine and / or DL-alanine having no acidity or acid odor can increase the effect of reducing the heat resistance of bacterial spores without changing the pH of the food.

  Furthermore, since the effect of the heat-reducing agent for bacterial spores of the present invention increases when used together with heating, it can be widely used for various processed foods and cooked foods. Moreover, it is not necessary to heat excessively, and since the heat-resistant reduction effect of a bacterial spore is exhibited on the original heating conditions of processed and cooked food, the flavor of food is not impaired.

The metaphosphoric acid used in the present invention is typically a linear metalin having a structure in which two or more PO ₄ tetrahedrons share an apex oxygen atom and are linearly linked by dehydration condensation of orthophosphoric acid. The acid may be a side chain polyphosphoric acid having an organic group introduced in the side chain, a cyclic metaphosphoric acid, a polyphosphoric acid having a branched phosphoric acid polymer structure, or a mixture thereof.

  The metaphosphoric acid particularly preferably used in the present invention has the general formula:

Or a mixture of two or more types of linear phosphoric acid represented by the formula:

  N in the above general formula is an integer of 3 to 800, preferably 15 to 500, more preferably 40 to 300, and most preferably 40 to 100. Polyphosphoric acid having a chain length of 1000 or more is not preferable because it is hardly soluble in water, and the polyphosphoric acid has a chain length of about 800 in vivo, so that polyphosphoric acid having a chain length of 800 or less is in vivo. (KD Kumble and A. Koruberg, Inorganic polyphosphate in mammalian cells and tissues. The Journal of Biological Chemistry, vol. 270, pp. 5818-5822, 1995) and metaphosphoric acid. Is gradually hydrolyzed in an aqueous solution to polyphosphoric acid, so that the number of n of metaphosphoric acid is functionally within a practical range of 3 to 800.

  In the present invention, a metaphosphate having a molecular structure in which hydrogen of the hydroxyl group of the metaphosphoric acid is substituted with a metal may be used. Examples of the metal include sodium, potassium, calcium, and magnesium.

  One kind of metaphosphoric acid or a salt thereof used in the present invention may be used, but a mixture of plural kinds may be used. The plural types of metaphosphoric acids or salts thereof include metaphosphoric acids or salts thereof having different degrees of polymerization, metaphosphoric acids or salts thereof having different molecular structures, and metaphosphates having different metal ions. Moreover, you may include both polyphosphoric acid and its salt.

  Said metaphosphoric acid can be manufactured by the manufacturing method used normally, such as the method of heating phosphoric acid, the method of adding and dissolving phosphorus pentoxide in phosphoric acid.

  In the present invention, glycine and / or DL-alanine used in combination with metaphosphoric acid may be of a grade that can be added to food.

  The compounding content of metaphosphate and glycine and / or DL-alanine is not particularly limited as long as it enhances the heat resistance lowering effect of bacterial spores. For example, sodium metaphosphate when added to food: glycine and / or DL -What is necessary is just to adjust the compounding ratio of alanine (concentration ratio) to about 1: 1 to 1: 100.

  The heat-reducing agent for bacterial spores of the present invention can contain a natural antibacterial substance, an organic acid or a salt thereof, and other components that can be usually blended in a food preservative, if necessary. When these components are contained in the heat-resistant agent for bacterial spore of the present invention, it is preferable to contain about 5 to 40% by weight based on the total weight of the heat-resistant agent for bacterial spore.

  Examples of natural antibacterial substances include protamine, polylysine, lysozyme, chitosan, capsicum aqueous extract, hop extract, and plant lecithin. Examples of organic acids or salts thereof include fumaric acid, acetic acid, sodium acetate, adipic acid, citric acid, sodium citrate, sorbic acid, sorbic acid K, DL-malic acid, DL-malic acid Na, succinic acid, and succinic acid. 2Na, gluconic acid, glucono delta lactone, Na propionate, Ca propionate, Na dehydroacetate and the like.

  The target food to which the present invention is applied is not particularly limited, and includes foods that require storage as processed foods. The food may be distributed or stored at room temperature, refrigerated or frozen, and the processed food includes not only cooked processed products but also semi-cooked processed foods.

  Typical examples of processed foods include processed meat products such as ham, sausage and hamburger, marine products such as kamaboko and chikuwa, packaged pickles that are heat sterilized such as potatoes, noodles such as Chinese noodles, udon and soba Long-life packaged foods such as fried eggs, vegetables, white rice and red rice, Japanese and Western confectionery such as cream and rice cakes, various drinks such as noodle soup and sauce, vegetables and fruit juice, etc. It is not a thing.

  The present invention shows that metaphosphoric acid has an effect of lowering the heat resistance of heat-resistant bacterial spores, and this effect is further enhanced when used in combination with glycine and / or DL-alanine and heating.

  In the bacterial spore germination / development suppression method of the present invention, the heat treatment conditions are effective even at room temperature without heating, so even a slight heating can be expected to have a combined effect. Heating conditions used for measures against heat-resistant spores of packaged foods, or heat sterilization conditions in the cooking process, and in each case, combined use with heating reduces the heating temperature and shortens the time, resulting in loss of food flavor Can be suppressed.

  From this point of view, the heat treatment conditions of the germination and growth suppression method of bacterial spores are preferably 25 to 98 ° C. and 5 to 30 minutes, more preferably 60 to 98 ° C. and 5 to 30 minutes, More preferably, it is 70-98 degreeC and 10-30 minutes.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

1. Verification of Spore Germination Suppression Effect (1) Preparation of Spore Fluid As heat-resistant spore-forming bacteria, Bacillus licheniformis IFO 12195 and Bacillus cereus NBRC 13494 were used. The spores are cultured on a standard agar medium diluted to 70% for 30 days at 30 ° C for 4 days. The surface bacteria are suspended in 50 vol% ethanol and kept in a refrigerator at 4 ° C for 5 hours to sterilize vegetative cells. Thereafter, a solution diluted 100 times with sterilized water was used. Using these spore fluids, the effect of sodium metaphosphate on spore germination, the combined use with glycine, and the combined use with heating were tested.

(2) Spore germination inhibiting effect General formula (HPO ₃ ) Inoculated with spore solution in tryptosoy liquid medium (pH 6.0) containing sodium metaphosphate mixture 0.01-0.1% and n-glycol 0.1-1.0% where n is 40-60 (Containing 3.1 × 10 ³ cfu / ml spore), heated in a 90 ° C. hot water bath at 0, 5, and 10 minutes at a reaching temperature. After quenching, it was placed in a thermostatic chamber at 30 ° C., and the turbidity of the test solution due to germination and growth was judged with the naked eye, and the number of days in which turbidity was observed was examined. The results are shown in Tables 1-6. -Indicates that no growth was observed for 7 days. The concentration (%) means weight% (the same applies hereinafter).

  From the above results, it was found that the heat resistance reducing agent for bacterial spores of the present invention is a composition having an effect of delaying germination and growth in an environment where heat resistant spores can germinate and grow.

  Table 1 shows the combined effect of sodium metaphosphate and glycine at room temperature when not heated against Bacillus licheniformis IFO 12195, and Table 4 against Bacillus cereus NBRC 13494. Although glycine is 0, that is, sodium metaphosphate alone, the number of days to germinate and grow increases as the concentration of addition increases, and at 0.05% or more, germination / growth inhibition for 7 days was observed. . When used in combination with glycine, the number of days to suppress germination and growth was dramatically increased. Furthermore, Tables 2 and 3 are heated against Bacillus licheniformis IFO 12195, and Tables 5 and 6 are heated against Bacillus cereus NBRC 13494 at 90 ° C. for 5 minutes and 10 minutes. This shows the number of days in which germination was suppressed when used together, and germination and growth were further dramatically suppressed by heating, and a decrease in heat resistance was observed.

2. Measures for spore bacteria in hermetically sealed sweet potatoes After washing the unsweetened sweet potatoes with water, cutting them into pieces of 2cm thickness, blanching them, and adding them to a small amount of sodium metaphosphate in a packaging container (P: 40-60) ) And glycine solution, and then the spore of Bacillus cereus NBRC 13494, a thermostable spore-forming bacterium, is 5.0 × 10 ³ cfu / g and spore of Clostridium sporogenes NBRC 14293 Was inoculated with 3.0 × 10 ² cfu / g and deaerated. Cooked at 90 ° C. for 20 minutes, 10 pieces per test area were stored at 25 ° C., and the preservative effect was judged by visually observing the storage stability. As a criterion, the five-step evaluation method shown in Table 7 was used, and the number of days until reaching an average score of 1 was defined as the effective storage days. Table 8 shows the test plots and storage days.

3. Inhibition of heat-resistant spore bacteria in the water soaking process of dried soybeans Dry soybeans are used in many processed soybean products such as tofu, natto, miso and soy sauce. In the production of these processed products, there are cases where spoilage germs and growth of spore bacteria adhering to soybean during water soaking of dried soybean may cause spoilage. The test example which suppresses this was shown below.

  Dried soybean (Hokkaido) 25g (1 test category) was put into a colander, washed with tap water for 30 seconds while showering, drained, and then immersed in 90g of tap water to which chemicals having the composition shown in Table 9 were added ( The drug was used based on the total amount of soybean and tap water). Dilute plate using standard agar medium for storage of general viable count (cfu / mL) of soaking solution after 30 hours at 30 ° C with soy soaked, 0 hours (immediately after soaking), 18 hours, 24 hours later Measured by culture method. The results are shown in Table 9.

4). Measures against spore bacteria derived from wheat flour of Chinese noodles 1 kg of flour has the composition shown in Table 10 (P = 40-100 is 90%, the remaining 10% is P = 3-40 and P = 100 ~ 300), 10g of salt, 12g of powdered rice cake and 0.4g of edible yellow pigment dissolved in 360ml of water, kneaded for 10 minutes, rolled and noodles with incisors (# 20) Raw Chinese noodles were produced by cutting out the lines. Half was wrapped in raw Chinese noodles in 40g increments, and the other half was steamed as Chinese noodles at 98 ° C, rinsed, drained, and packaged in 40g nylon plastic bags. The raw Chinese steamed noodles and steamed Chinese noodles thus prepared were stored at 30 ° C. for 10 test groups, the appearance was observed over time, and the antiseptic effect was judged according to the deterioration criteria shown in Table 11. The result is shown in the effective storage days of Table 12. The effective preservation days were defined as the number of days until the average score of deterioration was 1 point.

  As can be seen in Table 12, in the raw Chinese noodles, although the storage days were extended by sodium metaphosphate (P = 3-300) alone or in combination with glycine and / or DL-alanine, the heated steamed Chinese noodles Thus, the storage stability was dramatically improved by using sodium metaphosphate (P = 3 to 300), glycine or DL-alanine together.

Claims (6)

The following general formula:
Metaphosphoric acid composed of one or a mixture of two or more linear phosphoric acids represented by:
Glycine and / or DL-alanine,
Bacterial spore heat resistance-reducing agent containing as an active ingredient.   The heat resistance reducing agent for bacterial spores according to claim 1, wherein the metaphosphoric acid is a metaphosphate.   The heat-reducing agent for bacterial spores according to claim 2, wherein the metaphosphate is at least one selected from the group consisting of sodium salts, potassium salts, calcium salts, and magnesium salts.   The heat resistance reducing agent for bacterial spores according to any one of claims 1 to 3, wherein a mixing ratio of the metaphosphoric acid and the glycine and / or DL-alanine is 1: 1 to 1: 100 in a concentration ratio. Adding the heat resistance reducing agent according to any one of claims 1 to 4 to the food;
A step of heat-treating the food;
A method for inhibiting germination and growth of bacterial spores.   The germination / development method of bacterial spores according to claim 5, wherein the heat treatment conditions are 25 to 98 ° C and 5 to 30 minutes.