Improvement method for bacteriostatic property of bacteriostatic agent

Abstract

To provide a method for improving the bacteriostatic property of a bacteriostatic agent in an actual food system.SOLUTION: In an improvement method for the bacteriostatic property of a bacteriostatic agent, (a) glycerin fatty acid ester whose constituent fatty acid is a 12-14C fatty acid and / or (b) diglycerin fatty acid ester whose constituent fatty acid is a 12-14C fatty acid as the bacteriostatic agent is dispersed in oil and fat to prepare a bacteriostatic oil and fat composition. According to the present invention, the bacteriostatic property of the bacteriostatic agent for food can be improved.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for improving the bacteriostatic properties of a bacteriostatic agent. [Background technology]

[0002] In order to maintain the freshness of many commercially distributed foods from the time of production until consumption by consumers, in addition to methods such as freezing and heat sterilization, food bacteriostatic agents are added.

[0003] As bacteriostatic agents for food, those using food emulsifiers having bacteriostatic effect are widely used. For example, there are known antibacterial agents characterized by containing a polyglycerol fatty acid ester and a polyglycerol condensed ricinoleic acid ester (Patent Document 1); an agent for improving the shelf life of food, which contains a polyglycerol fatty acid ester (a), which is an ester of a polyglycerol having an average degree of polymerization of 2 to 3 and a fatty acid, and in which the monoester content in the ester is 50 mass% or more, a thickening stabilizer (b) and water (c), and in which the content of (a) is 10 to 40 mass% in 100 mass% of the improver and the content of (b) is 0.01 to 30 mass% in 100 mass% of the improver (Patent Document 2); Patent Document 3 discloses a food preservative obtained by mixing 1 part by weight of a solution containing 20 to 50% by weight of a mono-, di-, or tri-fatty acid glycerol ester composed of a fatty acid of any one of the above Nos. 8 and glycerol, 10 to 30% by weight of a sulfosuccinic acid ester, 0 to 10% by weight of one or more alcohols selected from ethanol, propanol, and isopropanol, and 0 to 55% by weight of (E) water, with 1 to 500 parts by weight of an aqueous base. Patent Document 4 also discloses a shelf life extender for boiled eggs, which contains (a) a decaglycerol fatty acid ester having a constituent fatty acid with a carbon number of 10 to 14, (b) a diglycerol fatty acid ester having a constituent fatty acid with a carbon number of 6 to 14, (c) a glycerol organic acid fatty acid ester, (d) ethanol, and (e) water.

[0004] On the other hand, among food emulsifiers, glycerin fatty acid esters have a high bacteriostatic effect in culture medium tests, but it is known that the bacteriostatic effect is reduced in actual food systems because they contain a lot of starch and protein (Non-Patent Document 1).

[0005] For this reason, if the bacteriostatic properties of a bacteriostatic agent can be improved in actual food systems, it is believed that the agent can be utilized more effectively than at present. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2001-316206 A [Patent Document 2] JP 2006-280386 A [Patent Document 3] JP 2011-217668 A [Patent Document 4] JP 2014-042518 A [Non-patent literature]

[0007] [Non-Patent Document 1] Nobuyuki Kato and Isao Shibasaki, Journal of Fermentation Technology (1975), Vol. 53, No. 11, pp. 793-801 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to provide a method for improving the bacteriostatic properties of bacteriostatic agents in real food systems. [Means for solving the problem]

[0009] The inventors discovered that by dispersing glycerin fatty acid esters and / or diglycerin fatty acid esters, which are food emulsifiers composed of specific constituent fatty acids, in edible oils and fats and adding them to food, the bacteriostatic effect of these food emulsifiers in food systems is improved, and they have completed the present invention based on this finding.

[0010] That is, the present invention comprises a method for improving the bacteriostatic activity of a bacteriostatic agent, which comprises dispersing (a) a glycerol fatty acid ester whose constituent fatty acids have 12 to 14 carbon atoms and / or (b) a diglycerol fatty acid ester whose constituent fatty acids have 12 to 14 carbon atoms in an oil or fat to prepare an oil or fat composition for bacteriostasis. Effect of the Invention

[0011] According to the present invention, the bacteriostatic property of a bacteriostatic agent for food can be improved. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The glycerin fatty acid ester (a) in which the constituent fatty acid has 12 to 14 carbon atoms [hereinafter referred to as component (a)] used as the bacteriostatic agent in the present invention is an ester of glycerin and a fatty acid having 12 to 14 carbon atoms, and can be produced by a method known per se, such as an esterification reaction or an ester exchange reaction. If the constituent fatty acid of the ester has less than 12 carbon atoms, it is not preferred because it has a large effect on the flavor of the food. If the constituent fatty acid of the ester has more than 14 carbon atoms, it is not preferred because the effect of the present invention cannot be sufficiently obtained. In addition, the ester is preferably a monoester.

[0013] The fatty acid constituting component (a) is not particularly limited as long as it is a fatty acid having 12 to 14 carbon atoms originating from edible animal and vegetable fats and oils, and examples thereof include saturated fatty acids having 12 to 14 carbon atoms or unsaturated fatty acids having 12 to 14 carbon atoms (e.g., lauric acid, tridecylic acid, myristic acid, myristoleic acid, etc.). Among these, lauric acid and myristic acid are preferred. These fatty acids may be used alone or in any combination of two kinds. Furthermore, these fatty acids may contain fatty acids other than fatty acids having 12 to 14 carbon atoms, as long as the object and effect of the present invention are achieved. In this case, the content of fatty acids having 12 to 14 carbon atoms in 100% by mass of the constituent fatty acids of component (a) is 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0014] As the component (a), for example, glycerin monolaurate (trade name: Poem M-300; manufactured by Riken Vitamin Co., Ltd.) is commercially produced and sold, and this can be used in the present invention.

[0015] The diglycerol fatty acid ester (b) in which the constituent fatty acid has 12 to 14 carbon atoms [hereinafter referred to as component (b)] used as the bacteriostatic agent in the present invention is an ester of diglycerol and a fatty acid having 12 to 14 carbon atoms, and can be produced by a method known per se, such as an esterification reaction or an ester exchange reaction. If the constituent fatty acid of the ester has less than 12 carbon atoms, it is not preferred because it has a large effect on the flavor of the food. If the constituent fatty acid of the ester has more than 14 carbon atoms, it is not preferred because the effect of the present invention cannot be sufficiently obtained. In addition, the ester is preferably a monoester.

[0016] The fatty acid constituting component (b) is not particularly limited as long as it is a fatty acid having 12 to 14 carbon atoms originating from edible animal and vegetable fats and oils, and examples thereof include saturated fatty acids having 12 to 14 carbon atoms or unsaturated fatty acids having 12 to 14 carbon atoms (e.g., lauric acid, tridecylic acid, myristic acid, myristoleic acid, etc.). Among these, lauric acid and myristic acid are preferred. These fatty acids may be used alone or in any combination of two types. Furthermore, these fatty acids may contain fatty acids other than fatty acids having 12 to 14 carbon atoms, as long as the object and effect of the present invention are achieved. In this case, the content of fatty acids having 12 to 14 carbon atoms in 100% by mass of the constituent fatty acids of component (b) is 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.

[0017] As component (b), for example, Poem DM-100 (trade name; diglycerol monomyristate ester; manufactured by Riken Vitamin Co., Ltd.) and the like are commercially manufactured and sold, and these can be used in the present invention.

[0018] The method for improving the bacteriostatic property of the bacteriostatic agent of the present invention can be carried out by preparing a bacteriostatic oil-and-fat composition by dispersing component (a) and / or component (b) in an oil. Thus, the bacteriostatic oil-and-fat composition has a form in which component (a) and / or component (b) are dispersed in an oil. There is no particular limitation on the nature of the bacteriostatic oil-and-fat composition, and it may be liquid or powdered. Below, an outline of a preferred preparation method for each of the liquid bacteriostatic oil-and-fat composition and the powdered bacteriostatic oil-and-fat composition will be shown.

[0019] [Method for preparing liquid bacteriostatic oil composition] The liquid bacteriostatic oil-and-fat composition can be obtained, for example, by heating and mixing edible oil-and-fat that is liquid at room temperature and component (a) and / or component (b) to prepare a composition in which component (a) and / or component (b) are dispersed in edible oil-and-fat that is liquid at room temperature, and then cooling the composition to room temperature. The heating temperature is preferably, for example, 60 to 90°C.

[0020] The edible oils and fats that are liquid at room temperature are not particularly limited as long as they are liquid at room temperature (15 to 25° C.). Examples of such oils and fats include safflower oil, soybean oil, cottonseed oil, rice oil, rapeseed oil, corn oil, olive oil, etc. These edible oils and fats that are liquid at room temperature may be used alone or in any combination of two or more kinds.

[0021] There are no particular limitations on the contents of edible oils and fats that are liquid at room temperature and component (a) and / or component (b) in 100% by mass of the liquid bacteriostatic oil and fat composition, but for example, the content of edible oils and fats that are liquid at room temperature is 20 to 95% by mass, preferably 30 to 90% by mass, and more preferably 40 to 85% by mass, and the content of component (a) and / or component (b) is 5 to 80% by mass, preferably 10 to 70% by mass, and more preferably 15 to 60% by mass.

[0022] [Method for preparing powdered bacteriostatic oil composition] First, solid edible oil and fat and component (a) and / or component (b) are melt-mixed at room temperature (15 to 25°C) to obtain a melt in which component (a) and / or component (b) are dispersed in edible oil and fat that is solid at room temperature. Here, melt-mixing refers to heating various components to make them liquid or slurry-like and mixing them. The heating temperature is preferably, for example, 70 to 100°C.

[0023] Next, the obtained melt is cooled and solidified and pulverized by a method known per se. More specifically, for example, a method of simultaneously cooling and solidifying the melt by spray cooling and pulverizing the melt, a method of once cooling and solidifying the melt to a solid state, and then physically pulverizing the solid using a compression crusher, a shear crusher, an impact crusher, or the like, to pulverize the solid, and the like. The cooling temperature is not particularly limited as long as each component is in a solid state, but is usually -196 to 30°C. As a guideline for pulverization, there is no particular limit as long as the particle diameter of the particles constituting the powder is within a range that does not impair the purpose and effect of the present invention, but for example, it is preferable that the average particle diameter (median diameter) is 500 μm or less.

[0024] The edible fats and oils that are solid at room temperature are not particularly limited as long as they are edible fats and oils derived from animals and plants and are solid or semi-solid at room temperature. Examples of such fats and oils include solid fats such as milk fat, coconut oil, palm oil, beef tallow, lard, and cacao butter, hardened oils obtained by subjecting these solid fats or liquid oils that are liquid at room temperature (safflower oil, soybean oil, cottonseed oil, rice oil, rapeseed oil, olive oil, etc.) to hydrogenation (hardening) treatment, and processed fats and oils obtained by further subjecting these to fractionation, ester exchange, etc. Among these, hardened oils, particularly extremely hardened oils with an iodine value of 2 or less, preferably 0.5 or less, are preferred, and palm extremely hardened oil is particularly preferred. These edible fats and oils that are solid at room temperature may be used alone or in any combination of two or more types.

[0025] There are no particular limitations on the contents of edible oils and fats that are solid at room temperature and component (a) and / or component (b) in 100% by mass of the powdered bacteriostatic oil and fat composition, but for example, the content of edible oils and fats that are solid at room temperature is 20 to 95% by mass, preferably 30 to 90% by mass, and more preferably 40 to 85% by mass, and the content of component (a) and / or component (b) is 5 to 80% by mass, preferably 10 to 70% by mass, and more preferably 15 to 60% by mass.

[0026] The bacteriostatic oil and fat composition according to the present invention may contain any other component in addition to edible oils and fats that are liquid at room temperature, edible oils and fats that are solid at room temperature, and components (a) and (b) as long as the effects of the present invention are not impaired. Examples of such components include emulsifiers other than components (a) and (b), antioxidants (extracted tocopherol, L-ascorbic acid palmitic acid ester, components having bacteriostatic properties other than components (a) and (b) (organic acids such as adipic acid, citric acid, glucono delta lactone, gluconic acid, tartaric acid, lactic acid, acetic acid, fumaric acid, oxalic acid, malic acid, and succinic acid; organic acid salts such as sodium salts and potassium salts of the organic acids; inorganic acids such as pyrophosphoric acid, polyphosphoric acid, metaphosphoric acid, and phosphoric acid; tetrapotassium pyrophosphate, disodium dihydrogen pyrophosphate, tetrasodium pyrophosphate, potassium polyphosphate, sodium polyphosphate, potassium metaphosphate, sodium metaphosphate, tripotassium phosphate, lithium phosphate, potassium phosphate, sodium ... Examples of such additives include inorganic acid salts such as trisodium phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, and sodium dihydrogen phosphate; glycine; lysozyme; ε-polylysine; thiamine lauryl sulfate; milt protein extract; pectin hydrolysates, etc.), excipients (monosaccharides such as glucose and fructose; oligosaccharides such as sucrose, lactose, and maltose; starch hydrolysates such as dextrin and powdered starch syrup; maltotriose, maltotetraose, maltopentaose, and maltohexaose; sugar alcohols such as sorbitol, mannitol, maltitol, and powdered reduced starch syrup; starches such as corn starch, etc.), and flour quality improvers (calcium phosphate, fine silicon dioxide, etc.).

[0027] The bacteriostatic oil and fat composition according to the present invention is used by adding it to a food to be improved in shelf life. The amount of the bacteriostatic oil and fat composition to be added to a food varies depending on the type of food, the initial cell count of the food, the intended storage period, etc., but the component (a) and / or the component (b) can be added in an amount of preferably 0.001 to 0.5 parts by mass, more preferably 0.005 to 0.1 parts by mass, per 100 parts by mass of the food.

[0028] There is no particular limitation on the method of using the bacteriostatic oil and fat composition according to the present invention. For example, it can be added appropriately during the production of food depending on the type and production method of the food.

[0029] There is no particular limitation on the foods to which the bacteriostatic oil and fat composition according to the present invention is added, and examples of such foods include confectioneries such as donuts, sponge cakes, steamed cakes, steamed bread, bean-jam buns, cream buns, pancakes, and cream puffs, desserts such as ice cream, pudding, bavarois, yogurt, fruit jelly, coffee jelly, and almond jelly, salads such as egg salad, macaroni salad, and potato salad, processed meat products such as sausages, ham, roast pork, pork cutlets, fried chicken, meatballs, shumai, and gyoza, seasonings such as seasoned miso, sesame sauce, and dressings, fish paste products such as kamaboko, chikuwa, and hanpen, pickled plums, and other condiments. pickles such as takuan (pickled radish), lightly pickled vegetables, and kimchi; bean paste fillings such as custard cream, red bean paste, and flower paste; jams such as strawberry jam and marmalade; processed seafood products such as shiokara (shiokara), mirin-boshi (dry rice with mirin), and one-night-dried fish; egg products such as tamagoyaki (rolled omelet), omelettes, and scrambled eggs; noodles such as udon, soba, and yakisoba (fried noodles); sandwiches such as egg sandwiches and ham sandwiches; rice balls such as red rice balls, salmon rice balls, and rice balls with plums; tsukudani (food cooked in soy sauce) such as squid tsukudani and nori tsukudani (seaweed boiled in soy sauce); simmered foods such as oden, simmered kelp, and simmered vegetables; fried foods such as fried shrimp, fried oysters, and croquettes; and processed tofu foods such as tofu, deep-fried tofu, and thin deep-fried tofu.

[0030] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. EXAMPLES

[0031] [Bacteriostatic test against culture medium] (1) Preparation method of Example 1 100 g of diglycerol monomyristate (product name: Poem DM-100; manufactured by Riken Vitamin Co., Ltd.) and 100 g of rapeseed oil (manufactured by Boso Oil Co., Ltd.) were weighed into a 300 ml beaker and mixed by stirring with a spatula while heating to 80°C, to prepare a liquid oil composition (Example Product 1) in which diglycerol monomyristate was dispersed in rapeseed oil.

[0032] (2) Preparation method of Comparative Example 1 50 g of diglycerol monomyristate (product name: Poem DM-100; manufactured by Riken Vitamin Co., Ltd.) and 150 g of ion-exchanged water were weighed into a 300 ml beaker, heated to 80°C, and mixed while stirring at 5,000 rpm using a TK Homomixer (model: MARKII; manufactured by Primix Corporation) to prepare an aqueous dispersion in which diglycerol monomyristate was dispersed in water (Comparative Example Product 1).

[0033] (3) Preparation of culture medium and evaluation of bacteriostasis First, a food-based medium was prepared by adding wheat starch. More specifically, 3.5 g of normal agar medium (manufactured by Nissui Pharmaceutical Co., Ltd.), 4 g of wheat starch (manufactured by Matsutani Chemical Industry Co., Ltd.), and Example Product 1 or Comparative Example Product 1 were dispersed in 100 ml of ion-exchanged water, and autoclaved at 121°C for 15 minutes. This was cooled to 50°C and added to a sterilized petri dish to prepare a normal plate medium. The concentrations of diglycerol monomyristate in the plate medium were set to 10 ppm, 50 ppm, 100 ppm, 200 ppm, 400 ppm, 800 ppm, 1600 ppm, and 3200 ppm. Next, a loopful of frozen preserved "Bacillus cereus NBRC 103938" (hereinafter referred to as B. cereus) or "Bacillus sphaericus NBRC 15095" (hereinafter referred to as B. sphaericus) was smeared onto each plate medium and cultured at 30°C for 48 hours. The minimum concentration at which the growth of the bacteria was inhibited [minimum inhibitory concentration = MIC (ppm)] for diglycerol monomyristate was measured, and the results are shown in Table 1.

[0034] [Table 1]

[0035] As is clear from Table 1, when Example Product 1 was used, the MIC of diglycerol monomyristate was lower for both B. cereus and B. sphaericus than when Comparative Example Product 1 was used. This shows that by dispersing diglycerol monomyristate in fats and oils to prepare an oil composition, the bacteriostatic activity of diglycerol monomyristate is improved in a medium simulating a food system.

[0036] [Bacteriostatic test for steamed cake 1] (1) Method for preparing Example Product 2 and Comparative Example Product 2 Example product 2 was prepared in the same manner as Example product 1, and Comparative example product 2 was prepared in the same manner as Comparative example product 1. The content of diglycerol monomyristate ester in Example product 2 was 50% by mass, and that in Comparative example product 2 was 25% by mass.

[0037] (2) Method for producing steamed cake 100 g of plain flour (product name: Violet; manufactured by Nisshin Flour Milling Co., Ltd.), 180 g of caster sugar, 130 g of sterilized liquid egg (product name: Excel Egg HV; manufactured by Kewpie Egg Co., Ltd.), 80 g of confectionery fat (product name: Pati Glace-TD; manufactured by Riken Vitamin Co., Ltd.), 10 g of emulsifier-containing fat composition (product name: Ematec N-100V; manufactured by Riken Vitamin Co., Ltd.), 10 g of triple concentrated milk (product name: Millex 200M; manufactured by Kaneka Co., Ltd.), 1 g of baking soda, 4 g of baking powder (product name: BP (C#1); manufactured by Oriental Yeast Co., Ltd.), 1 g of soy sauce, 10 g of water, 1 g of Example Product 2 or 2 g of Comparative Example Product 2 were placed in a mixer bowl, and mixed using a 5-coat vertical mixer (model: universal mixer 5DMr; manufactured by Shinagawa Kogyosho Co., Ltd., equipped with a wire whipper) at low speed: 1 minute 30 seconds → high speed: 1 minute 10 seconds → Low speed: Mix for 10 seconds to obtain cake dough by the all-in-mix method. The cake dough was divided into 90 g portions, placed on silicone-coated glassine paper with a diameter of 7 cm, placed in a steamer box (model: K-1DX; manufactured by Asami Co., Ltd.), and steamed at 98°C for 16 minutes to obtain steamed cakes 1 and 2. The amount of diglycerol monomyristate added to each of these steamed cakes was set to about 0.1% by mass. In addition, the same procedure was carried out except that neither Example Product 2 nor Comparative Example Product 2 was added, to produce steamed cake 3 containing no bacteriostatic agent.

[0038] (3) Evaluation of bacteriostasis The resulting steamed cake was inoculated with a frozen preserved bacterial solution of B. spp. at a concentration of 10 cfu / g. The bacterial solution was prepared by mixing a culture solution of B. spp. with sterilized physiological saline and inoculating the mixture at 10 3 The bacterial concentration was expressed as cfu / ml. The steamed cake inoculated with the bacterial liquid was then stored at 30°C for 120 hours, after which the bacterial count was measured. The bacterial count was measured according to the official method (Food Sanitation Inspection Guidelines). The results are shown in Table 2.

[0039] [Table 2]

[0040] As is clear from Table 2, when Example Product 2 was used, the number of B. sphaericus bacteria was reduced compared to when Comparative Example Product 2 was used. This shows that by dispersing diglycerol monomyristate in an oil and fat to prepare an oil and fat composition, the bacteriostatic activity of diglycerol monomyristate in the steamed cake is improved.

[0041] [Bacteriostatic test for steamed cake 2] (1) Preparation method of Example 3 66 g of glycerin monolaurate (trade name: Poem M-300; manufactured by Riken Vitamin Co., Ltd.) and 134 g of palm hardened oil (manufactured by Yokozeki Yushi Kogyo Co., Ltd.) were weighed into a 300 ml beaker and stirred with a glass rod while heating to 90 ° C. The resulting molten material was cooled and solidified in a cooling bath at 4 ° C., and then pulverized in a mixer (trade name: TM8100; manufactured by TESCOM Co., Ltd.), and the resulting pulverized material was passed through a 30 mesh (500 μm mesh) stainless steel sieve to obtain a powder (Example Product 3) with an average particle size of 200 μm. Note that each particle constituting the powder of Example Product 3 has a form in which glycerin monolaurate is dispersed in palm hardened oil.

[0042] (2) Comparative Example 3 A commercially available powdered emulsifier preparation containing glycerin monolaurate (product name: Poem M-300P (NA); glycerin monolaurate content 50% by mass; manufactured by Riken Vitamin Co., Ltd.) was used as Comparative Example Product 3. Note that this Comparative Example Product 3 was produced by the so-called spray drying method, and the individual particles constituting the powder do not have a morphology in which glycerin monolaurate is dispersed in fats and oils.

[0043] (3) Raw materials for bacteriostatic compositions 1) Glycine (Yugo Gosei Yakuhin Kogyo Co., Ltd.) 2) Sodium acetate (Air Water Performance Chemical) 3) Fumaric acid (Fuso Chemical Co., Ltd.) 4) Lysozyme (product name: egg white lysozyme; CANADIAN INOVATECH) 5) Cornstarch (Matsutani Chemical Industry Co., Ltd.) 6) Example 3 7) Comparative Example 3

[0044] (3) Formulation of bacteriostatic composition The formulations of bacteriostatic compositions A and B prepared using the above raw materials are shown in Table 3.

[0045] [Table 3]

[0046] (4) Method for preparing a bacteriostatic composition The raw materials in 10 times the amount shown in Table 3 were placed in a plastic bag, the opening of the bag was tied and the mixture was stirred by hand for 3 minutes to mix uniformly, and bacteriostatic compositions A and B were obtained.

[0047] (5) Method for producing steamed cake 100g of plain flour (product name: Violet; manufactured by Nisshin Flour Milling Co., Ltd.), 180g of white sugar, 130g of sterilized liquid egg (product name: Excel Egg HV; manufactured by Kewpie Egg Co., Ltd.), 80g of fat for confectionery (product name: Patigrasse-TD; manufactured by Riken Vitamin Co., Ltd.), 10g of fat composition containing emulsifier (product name: Ematec N-100V; manufactured by Riken Vitamin Co., Ltd.), 10g of 3 times concentrated milk (product name: Millex 200M; manufactured by Kaneka Co., Ltd.), 1g of baking soda, 4g of baking powder (product name: BP (C#1); manufactured by Oriental Yeast Co., Ltd.), 1g of soy sauce, 10g of water, 5.3g of bacteriostatic composition A or 5.1g of bacteriostatic composition B are put into a mixer bowl, and mixed at low speed: 1 minute 30 seconds using a 5-coat vertical mixer (model: universal mixer 5DMr; manufactured by Shinagawa Kogyosho Co., Ltd., equipped with a wire whipper) → Mix at high speed: 1 minute 10 seconds → low speed: 10 seconds to obtain cake dough by the all-in-mix method. The cake dough was divided into 90 g portions, placed on silicone-coated glassine paper with a diameter of 7 cm, placed in a steamer box (model: K-1DX; manufactured by Asami Co., Ltd.), and steamed at 98°C for 16 minutes to obtain steamed cakes 4 and 5. The amount of glycerin monolaurate added to each of these steamed cakes was set to 0.04% by mass. In addition, the same procedure was carried out except that neither bacteriostatic composition A nor bacteriostatic composition B was added, to produce steamed cake 6 without the addition of a bacteriostatic agent.

[0048] (6) Evaluation of bacteriostasis The resulting steamed cake was inoculated with a bacterial solution of frozen preserved "Aspergillus penicillioides NBRC 100539" (hereinafter referred to as A. penicillioides) at 10 cfu / g. The bacterial solution was prepared by mixing a culture solution of A. penicillioides with sterilized physiological saline, and inoculating the mixture at 10 3 The bacterial concentration was expressed as cfu / ml. The steamed cakes inoculated with the bacterial liquid were then stored at 30°C for 192 hours, after which the growth state was observed and coded according to the following criteria. The results are shown in Table 4.

[0049] <Symbolization Standards> +: Growth observed in less than one third of the inoculated area ++: Growth observed in more than one-third but less than two-thirds of the inoculated area

[0050] [Table 4]

[0051] As is clear from Table 3, when bacteriostatic composition A containing Example Product 3 was used, the growth of A. penicillioides was suppressed more than when bacteriostatic composition B containing Comparative Example Product 3 was used. This shows that the bacteriostatic activity of glycerol monolaurate is improved in steamed cake by dispersing glycerol monolaurate in oil and fat to prepare an oil and fat composition.

[0052] [Bacteriostatic test against purine] (1) Preparation method of Example 4 40 g of glycerin monolaurate (trade name: Poem M-300; manufactured by Riken Vitamin Co., Ltd.) and 160 g of palm hardened oil (manufactured by Yokozeki Yushi Kogyo Co., Ltd.) were weighed into a 300 ml beaker and stirred with a glass rod while heating to 80 ° C. The resulting molten material was cooled and solidified in a cooling bath at 4 ° C., and then pulverized in a mixer (trade name: TM8100; manufactured by TESCOM Co., Ltd.), and the resulting pulverized material was passed through a 30 mesh (500 μm mesh) stainless steel sieve to obtain a powder with an average particle size of 200 μm (Example Product 4). Note that each particle constituting the powder of Example Product 4 has a form in which glycerin monolaurate is dispersed in palm hardened oil.

[0053] (2) Preparation method of Example 5 A powder with an average particle size of 200 μm (Example Product 5) was obtained in the same manner as in Example Product 4, except that 40 g of diglycerol monomyristate (product name: Poem DM-100; manufactured by Riken Vitamin Co., Ltd.) was used instead of 40 g of glycerol monolaurate (product name: Poem M-300; manufactured by Riken Vitamin Co., Ltd.). Each particle constituting the powder of Example Product 5 has a morphology in which diglycerol monomyristate is dispersed in extremely hardened palm oil.

[0054] (3) Comparative Examples 4 and 5 Glycerol monolaurate (product name: Poem M-300; manufactured by Riken Vitamin Co., Ltd.) and diglycerol monomyristate (product name: Poem DM-100; manufactured by Riken Vitamin Co., Ltd.) themselves were used as comparative examples 4 and 5, respectively.

[0055] (4) How to make pudding 300g of milk, 90g of eggs, 12g of egg yolk, 60g of granulated sugar, 0.6g of vanilla essence, 2.3g of Example product 4 or 5 or 0.46g of Comparative example product 4 or 5 were stirred and mixed while heating with a Three-One Motor (model: BL600; manufactured by HEIDON Co., Ltd.), and held for 3 minutes after reaching a temperature of 70°C. After that, the mixture was filtered through a sieve and divided into 50g portions, which were baked (85°C, 50 minutes) in a combi oven (model: FSCCXS 6 2 / 3E; manufactured by Fujimak Co., Ltd.) to obtain puddings 1 to 4. The amount of glycerin monolaurate or diglycerin monomyristate added to each of these puddings was set to 0.1%. In addition, the same procedure was carried out except that neither Example Products 4 nor 5 nor Comparative Examples 4 nor 5 were added, to produce Pudding 5 containing no bacteriostatic agent.

[0056] (5) Evaluation of bacteriostasis The resulting pudding was allowed to cool, and then a frozen preserved B. sphaericus liquid was inoculated at 10 cfu / g. The liquid was prepared by mixing a culture liquid of B. sphaericus strain with sterilized physiological saline, and inoculating the liquid at 10 3 The bacterial concentration was expressed as cfu / ml. The pudding inoculated with the bacterial solution was then stored at 15°C for 96 hours, after which the number of bacteria was measured. The method for measuring the number of bacteria was in accordance with the official method (Food Sanitation Inspection Guidelines). The results are shown in Table 5.

[0057] [Table 5]

[0058] As is clear from Table 5, when Example Products 4 and 5 were used, the growth of B. sphaericus was suppressed compared to when Comparative Examples 4 and 5 were used. This shows that glycerol monolaurate and diglycerol monomyristate can improve the bacteriostasis of pudding by dispersing them in fats and oils to prepare an oil and fat composition.

Claims

[Claim 1] A method for improving the bacteriostatic property of a bacteriostatic agent, comprising dispersing, as a bacteriostatic agent, (a) a glycerol fatty acid ester whose constituent fatty acids have 12 to 14 carbon atoms and / or (b) a diglycerol fatty acid ester whose constituent fatty acids have 12 to 14 carbon atoms in an oil or fat, to prepare an oil or fat composition for bacteriostasis.

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