Food and shelf life improver for foods

Abstract

This food contains: 0.2-2 mass% of sodium acetate, and 0.01-0.2 mass% of an organic acid, or 0.02-0.2 mass % of acetic acid; and 0.005-0.1 mass% of a ginger extract. This food has a pH of 5.0-7.0 at a product temperature of 25°C. The organic acid preferably includes at least one selected from the group consisting of acetic acid, citric acid, malic acid, fumaric acid, adipic acid, glucono-delta-lactone, gluconic acid, succinic acid, tartaric acid, ascorbic acid, and lactic acid.

Description

Food and shelf-life improving agent for food

[0001] The present invention relates to a food containing organic acids formulated for bacteriostatic purposes.

[0002] For the purpose of improving the storage stability of food, organic acids such as acetic acid and sodium acetate and salts thereof (organic acids) are sometimes formulated into food and drink. Since organic acids exhibit a bacteriostatic effect that suppresses the growth of microorganisms, formulating them into food and drink improves the storage stability of the food. Patent Document 1 describes a quality improving agent for cooked rice that suppresses the retrogradation of starch in cooked rice, makes cooked rice less prone to retrogradation even when stored for a long time, and can suppress dryness, which contains a heated sugar product in addition to organic acids. The heated sugar product is obtained by heat-treating fructose or a sugar composition containing fructose at 100 to 200°C.

[0003] However, when organic acids are formulated into food and drink, unpleasant sour taste and sour odor are imparted to the food, which may impair the original flavor of the food and drink. Patent Document 2 describes that a specific amino acid is contained in an acid-containing food or drink that contains acetic acid, which is a type of organic acid, and further describes that vegetable juice such as ginger juice may also be contained. It is stated that the acid-containing food and drink described in Patent Document 2 has reduced throat irritation peculiar to acetic acid and post-irritation remaining after swallowing.

[0004] Patent Document 3 describes a processed ginger food that contains salt, has a sour taste derived from brewed vinegar of fruits or cereals, and has a moisture content of 10% by weight or less. Patent Document 3 describes methods for using the processed ginger food, including a method of rehydrating and eating it as it is, and a method of adding it to various foods (soft drinks such as coffee, black tea, and green tea, soup-based beverages such as miso soup and soup, alcoholic beverages, etc.), and it is stated that the texture and flavor inherent to ginger can be enjoyed through these usage methods.

[0005] Japanese Patent Application Laid-Open No. 2021-061788, Japanese Patent Application Laid-Open No. 2023-034809, Japanese Patent Application Laid-Open No. 2023-041643

[0006] An object of the present invention is to provide a technique capable of improving the storage stability of food without impairing the inherent flavor of the food.

[0007] The inventors of the present invention have investigated various techniques for inhibiting the perception of sour taste and sour odor caused by organic acids in foods containing bacteriostatic organic acids. As a result, they have found that by adding a specific amount of ginger extract to a food containing such organic acids and with the pH adjusted to a specific range, it is possible to enjoy the inhibitory effect of the organic acids on microbial growth while inhibiting the perception of sour taste and sour odor caused by the organic acids.

[0008] The present invention is based on the above findings and is a food product containing 0.2 to 2% by mass of sodium acetate and 0.01 to 0.2% by mass of an organic acid, or 0.02 to 0.2% by mass of acetic acid, and 0.005 to 0.1% by mass of ginger extract, with a pH of 5.0 to 7.0 at a product temperature of 25°C.

[0009] Furthermore, the present invention is based on the above findings and is a food preservative containing 40 to 90% by mass of sodium acetate, 1 to 15% by mass of an organic acid, or 3 to 15% by mass of acetic acid, and 0.3 to 0.9% by mass of ginger extract, wherein the pH of a 1% by mass aqueous solution at a product temperature of 25°C is 4.0 to 6.0.

[0010] Furthermore, the present invention is based on the above findings and is a method for inhibiting the perception of sour taste and sour odor in a food containing sodium acetate or an organic acid, comprising including ginger extract in the food.

[0011] The food of the present invention includes a form containing sodium acetate and an organic acid (hereinafter also referred to as "first form") and a form containing acetic acid (hereinafter also referred to as "second form"). Sodium acetate, organic acid, and acetic acid mainly function as bacteriostatic agents that suppress the growth of microorganisms such as lactic acid bacteria and food poisoning bacteria, and contribute to improving the shelf life of the food.

[0012] The sodium acetate, organic acid, and acetic acid used in this invention may be any food-grade substances; for example, commercially available food additives can be used. Specific examples of sodium acetate include anhydrous sodium acetate and sodium acetate hydrate. These are solids (powder / granules) at room temperature and pressure. Examples of organic acids include acetic acid, citric acid, malic acid, fumaric acid, adipic acid, glucono delta-lactone, gluconic acid, succinic acid, tartaric acid, ascorbic acid, and lactic acid. These can be used individually or in combination of two or more. Among these, acetic acid, citric acid, and fumaric acid are particularly preferred.

[0013] The sodium acetate content in the first form of food is 0.2 to 2% by mass, preferably 0.3 to 1.8% by mass, and more preferably 0.4 to 1.5% by mass, based on the total mass of the food. The organic acid content in the first form of food is 0.01 to 0.2% by mass, preferably 0.03 to 0.15% by mass, and more preferably 0.05 to 0.1% by mass, based on the total mass of the food. If the sodium acetate content is less than 0.2% by mass, or the organic acid content is 0.01% by mass, a sufficient bacteriostatic effect cannot be obtained, and the food's shelf life cannot be improved. If the sodium acetate content is more than 2% by mass, or the organic acid content is more than 0.2% by mass, an undesirable sour taste and odor caused by sodium acetate and / or organic acids becomes prominent, and the food's inherent flavor may be impaired. The sodium acetate and organic acid content in food can be measured by known analytical methods such as high-performance liquid chromatography.

[0014] The acetic acid content in the second form of food is 0.02 to 0.2% by mass, preferably 0.04 to 0.15% by mass, and more preferably 0.05 to 0.1% by mass, relative to the total mass of the food. If the acetic acid content is less than 0.02% by mass, a sufficient bacteriostatic effect cannot be obtained, and the food's shelf life cannot be improved. If the acetic acid content exceeds 0.2% by mass, an undesirable sour taste and odor caused by acetic acid becomes prominent, and the food's inherent flavor may be impaired. The acetic acid content in food can be measured by known analytical methods such as high-performance liquid chromatography.

[0015] The food of the present invention contains ginger extract. The ginger extract functions as a masking agent that inhibits the perception of sour taste and sour odor mainly caused by sodium acetate, organic acids, or acetic acid, and contributes to maintaining the original flavor of the food. In this specification, "ginger extract" refers to an extract from ginger (scientific name: Zingiber officinale), a plant belonging to the genus Zingiber of the family Zingiberaceae. Components such as shogaol and gingerol contained in the ginger extract are presumed to be active ingredients that inhibit the perception of sour taste and sour odor caused by organic acids or acetic acid.

[0016] The part of the ginger used as the raw material for extraction is not particularly limited, provided that the functions expected of the ginger extract are expressed. Examples include leaves, branches, stems, flowers, buds, fruits, rhizomes, and above-ground parts, with the rhizome being preferred. The ginger used as the raw material for extraction may be heated before extraction, which may increase the content of the active ingredients. The method for extracting the ginger extract is not particularly limited, provided that the functions expected of the ginger extract are expressed. Any solvent extraction method commonly used when plants are used as raw materials can be used without particular restriction, such as stirring extraction, immersion extraction, countercurrent extraction, ultrasonic extraction, and supercritical fluid extraction. Examples of extraction solvents include water; lower aliphatic alcohols having 1 to 5 carbon atoms such as methanol, ethanol, propyl alcohol, and isopropyl alcohol; lower aliphatic ketones such as acetone and methyl ethyl ketone; and polyhydric alcohols having 2 to 5 carbon atoms such as 1,3-butylene glycol, propylene glycol, and glycerin. One of these can be used alone or in combination of two or more. In solvent extraction, the ginger extract obtained by solid-liquid separation by filtering or centrifuging the extract of the raw material may be heat-treated, or the liquid portion may be recovered by extraction or solid-liquid separation after heat treatment. The ginger extract used in the present invention may be the extract of the raw material; a concentrated or diluted solution of the extract; a dried product obtained by drying the extract, the concentrated or diluted solution; or a crude or purified product thereof.

[0017] The ginger extract may contain components other than ginger-derived components, provided that the functions expected of the ginger extract are expressed. Examples of such other components include emulsifiers, excipients such as dextrin, and stabilizers.

[0018] Commercially available ginger extracts can also be used. A preferred commercially available ginger extract is "Ginger Extract Powder" manufactured by Vidya Japan Co., Ltd.

[0019] The ginger extract content in the food of the present invention is 0.005 to 0.1% by mass, preferably 0.007 to 0.05% by mass, and more preferably 0.008 to 0.01% by mass, relative to the total mass of the food. If the ginger extract content is less than 0.005% by mass, there is a risk that the sour taste and odor caused by sodium acetate, organic acids, or acetic acid may not be sufficiently suppressed. If the ginger extract content exceeds 0.1% by mass, the ginger flavor of the food may become too strong, resulting in a loss of the food's inherent flavor. When using commercially available ginger extract, it is sufficient that the content of the commercially available ginger extract in the food of the present invention falls within the above range. The ginger extract content in the food can be measured by known analytical methods such as high-performance liquid chromatography.

[0020] The food of the present invention may contain other components besides the aforementioned components (sodium acetate, organic acid, acetic acid, and ginger extract). These other components may be those known to be included in foods of the same type as the food of the present invention (for example, the prepared foods, seasonings, or wheat processed foods described later), and one of these may be used alone or in combination of two or more.

[0021] The pH of the food of the present invention at a temperature of 25°C is 5.0 to 7.0, preferably 5.0 to 6.3, and more preferably 5.2 to 6.1. By having the pH of a food containing a bacteriostatic agent (such as sodium acetate) within the specified range, undesirable sour taste and odor caused by the bacteriostatic agent are suppressed, and the desirable taste inherent in the food can be maintained. The pH of the food can be adjusted by adjusting the content of each component contained in the food, in particular, the content of one or more of sodium acetate, organic acids, and acetic acid. Basically, the pH of the food can be adjusted within the specified range by adjusting the content of sodium acetate, organic acids, and acetic acid in the food to within the specified range.

[0022] The pH of food can be measured by the following method. A suitable amount is sampled from the food to be measured to serve as the measurement sample. The amount of the measurement sample can be set arbitrarily. If the measurement sample is liquid or paste-like, a pH measuring device is used to measure the pH of the measurement sample at a temperature of 25°C. If the measurement sample is solid, 5 parts by mass of ion-exchanged water are added to 1 part by mass of the measurement sample, and the mixture is made into a paste using a stomacher or mixer. A pH measuring device is then used to measure the pH of the mixture at a temperature of 25°C. If the food to be measured is a dough-heated food as described later, the pH of the dough before heating can be used as the pH of the food. For example, a glass electrode type hydrogen ion concentration indicator manufactured by Toa DKK Co., Ltd. can be used as the pH measuring device.

[0023] Specific examples of the food products of the present invention include rice dishes, prepared foods, seasonings, and wheat processed foods.

[0024] In this specification, "rice products" refers to food products that primarily consist of rice. The aforementioned "rice products" refer to food products that have been cooked by adding water to grains of the grass family, such as rice. Specific examples of rice products include rice balls, rice burgers, red bean rice, sticky rice, cooked rice, packaged rice, sprouted brown rice, and dried rice products.

[0025] In this specification, "prepared foods" refers to foods that are eaten with staple foods, excluding rice dishes, seasonings, and wheat processed foods. Specific examples of "staple foods" include rice dishes, noodles, and bread. Staple foods are not included in prepared foods. Specific examples of prepared foods include boiled dishes, salads, grilled dishes, stir-fried dishes, deep-fried dishes, and steamed dishes.

[0026] In this specification, "seasonings" refers to food products used to flavor dishes, excluding prepared foods and wheat-based foods. Specific examples of seasonings include pasta sauces, gratin sauces, dipping sauces, and duxelles sauces.

[0027] In this specification, "wheat processed food" refers to food containing a portion obtained by processing wheat (hereinafter also referred to as the "wheat-derived portion"). Wheat processed food may consist entirely of the wheat-derived portion, or only a portion of it may consist of the wheat-derived portion. A specific example of a wheat processed food is a dough-heated food. In this specification, "dough-heated food" refers to food manufactured by using dough, which is a mixture of powdered raw materials such as wheat flour and liquid raw materials such as water, as an intermediate product, shaping the dough into a predetermined form, and then heating it, and includes a dough portion obtained by heating the dough. The dough portion is the wheat-derived portion. The term "dough" here includes clay-like dough (so-called dough) and liquid or paste-like dough (so-called batter). Specific examples of dough-heated foods include bakery foods, noodles, and breaded fried foods. Typically, bakery foods and noodles consist entirely of the wheat-derived portion, whereas in breaded fried foods, the breading is partly the wheat-derived portion, while other parts, such as the filling, may not be the wheat-derived portion.

[0028] In this specification, "bakery food" refers to food obtained by heating dough containing flour such as wheat flour and water (heated dough food). Bakery food also includes products that contain other ingredients (e.g., fillings) in addition to the heated dough. Bakery food is typically produced by heating dough prepared through a process of stirring powdered raw materials, including flour, in the presence of water. The dough may be fermented or unfermented. The method of heating the dough is not particularly limited, and is typically by baking, but an appropriate method can be selected from known heating methods depending on the type of bakery food, etc. Examples include heating using a cooking appliance such as a deep fryer or microwave oven. Specific examples of bakery food include bread, steamed buns, waffles, crepes, pancakes, hotcakes, sponge cakes, scones, okonomiyaki, takoyaki, obanyaki, and taiyaki.

[0029] In this specification, "noodles" refers to food products obtained by shaping dough containing wheat flour or other grain flours and water into predetermined shapes such as lines or sheets to obtain fresh noodles, and then cooking (for example, boiling) the fresh noodles or dried noodles thereof. Specific examples of noodles include udon, somen, hiyamugi, soba, Chinese noodles, and pasta. Noodles also include noodle wrappers, and specific examples of noodle wrappers include dumpling wrappers, spring roll wrappers, and bao.

[0030] In this specification, "breaded fried food" refers to food obtained by coating the surface of ingredients with a batter containing grain flour such as wheat flour and then cooking it in hot oil. In breaded fried food, the batter is usually a wheat-based food, while the ingredients are not. The types of ingredients are not particularly limited and include, for example, meats such as chicken, pork, beef, lamb, and goat; seafood such as squid, octopus, shrimp, horse mackerel, salmon, mackerel, and flounder; grains, vegetables, and root vegetables such as soybeans, rice, carrots, onions, potatoes, and sweet potatoes; and processed products of these. Specific examples of breaded fried food include tempura, tatsuta-age, fritters, tonkatsu, and corn dogs.

[0031] Wheat processed foods may be manufactured using flours other than wheat flour. In this specification, "flours" refers to substances derived from grains that are powdery at room temperature and pressure, and is a concept that includes flour and starch. Unless otherwise specified, "starch" here refers to "pure starch" isolated from plants such as wheat, and is distinguished from starch inherently present in flour. Examples of such flours include wheat flour (strong flour, semi-strong flour, medium flour, weak flour, durum wheat flour, whole wheat flour, etc.), buckwheat flour, rice flour, corn flour, barley flour, rye flour, adlay flour, barnyard millet flour, and foxtail millet flour. Flours may also be subjected to heat treatments such as dry heat treatment or moist heat treatment. Examples of the starches include unprocessed starches such as tapioca starch, potato starch, corn starch, waxy corn starch, wheat starch, and rice starch; and processed starches obtained by subjecting unprocessed starches to one or more treatments such as etherification, esterification, acetylation, dry heat treatment, moist heat treatment, crosslinking treatment, and oxidation treatment.

[0032] The food of the present invention can typically be produced by a known method for producing the same type of food. In the production of the food of the present invention, the components to be included in the food (components according to the present invention), such as sodium acetate, organic acids, acetic acid, and ginger extract, can be used at any time during the production process of the known food of the same type.

[0033] Furthermore, the food of the present invention may be a pre-cooked frozen food that can be eaten as is after natural thawing. Generally, when frozen foods are naturally thawed, there is a concern that microorganisms such as spore-forming bacteria remaining in the frozen food may proliferate during the period of being left at room temperature. However, the food of the present invention has the aforementioned features, thus eliminating such concerns. The aforementioned pre-cooked frozen food is obtained by freezing pre-cooked foods such as prepared foods and wheat processed foods. In this specification, "natural thawing" refers to thawing by leaving the frozen food in an environment where the ambient temperature is room temperature (for example, around 10 to 30°C) or a chilled temperature range (for example, around 10°C to the freezing start temperature), and is different from heating and thawing using a heating appliance such as a microwave oven. Therefore, the food of the present invention can be stored, distributed, and / or sold in a chilled temperature range. In other words, the food of the present invention is applicable to a distribution and sales method in which the food is frozen after manufacture, and the frozen food is kept at a chilled temperature range during distribution to maintain a low temperature, and then sold in that low temperature state. Such so-called frozen-chilled sales can effectively reduce the deterioration of quality associated with the storage and distribution of food.

[0034] Next, the food shelf-life extender of the present invention (hereinafter also simply referred to as "the food shelf-life extender of the present invention") will be described. The configuration of the food shelf-life extender of the present invention will be described in a manner that differs from that of the food of the present invention described above. For configurations of the food shelf-life extender of the present invention that are not specifically described above, the description of the food of the present invention described above will be applied as appropriate.

[0035] The shelf-life extender of the present invention includes a form containing sodium acetate and an organic acid (hereinafter also referred to as "first form") and a form containing acetic acid (hereinafter also referred to as "second form"). The essential components (bacteriostatic agents) are as described above. From the viewpoint of ensuring that the shelf life of food is improved without impairing the original flavor of the food, the content of these essential components in both forms is preferably adjusted as follows. The sodium acetate content in the first form of the shelf-life extender is 40 to 90% by mass of the total mass of the shelf-life extender, preferably 50 to 85% by mass, and more preferably 60 to 80% by mass. The organic acid content in the first form of the shelf-life extender is 1 to 15% by mass of the total mass of the shelf-life extender, preferably 2 to 10% by mass, and more preferably 3 to 8% by mass. The acetic acid content in the second form of the shelf-life extender is 3 to 15% by mass of the total mass of the shelf-life extender, preferably 5 to 13% by mass, and more preferably 7 to 11% by mass. In the first form, if the sodium acetate content is less than 40% by mass, or the organic acid content is 1% by mass, a sufficient bacteriostatic effect cannot be obtained, and the shelf life of the food cannot be improved. Also in the first form, if the sodium acetate content exceeds 90% by mass, or the organic acid content exceeds 15% by mass, an undesirable sour taste and odor caused by sodium acetate and / or organic acids becomes prominent, and the original flavor of the food may be impaired. In the second form, if the acetic acid content is less than 3% by mass, a sufficient bacteriostatic effect cannot be obtained, and the shelf life of the food cannot be improved. Also in the second form, if the acetic acid content exceeds 15% by mass, an undesirable sour taste and odor caused by acetic acid becomes prominent, and the original flavor of the food may be impaired.

[0036] The shelf-life extender of the present invention contains ginger extract. The ginger extract is as described above. The content of ginger extract in the shelf-life extender of the present invention is 0.3 to 0.9% by mass, preferably 0.4 to 0.8% by mass, and more preferably 0.5 to 0.7% by mass, based on the total mass of the shelf-life extender. If the content of ginger extract is less than 0.3% by mass, there is a risk that the sour taste and odor caused by sodium acetate, organic acids, or acetic acid may not be sufficiently suppressed. If the content of ginger extract exceeds 0.9% by mass, there is a risk that the ginger flavor of the food will become too strong, resulting in the inherent flavor of the food being impaired. When using commercially available ginger extract, it is sufficient that the content of the commercially available ginger extract in the shelf-life extender of the present invention is within the above range.

[0037] The pH of a 1% by mass aqueous solution of the shelf-life extender of the present invention at a temperature of 25°C is 4.0 to 6.0, preferably 4.2 to 5.8, and more preferably 4.4 to 5.6. The aqueous solution is a mixture of the shelf-life extender and water, wherein the shelf-life extender is present in a liquid containing 1% by mass of the total mass of the aqueous solution. By keeping the pH of the aqueous solution within the specified range, undesirable sour taste and odor caused by bacteriostatic agents such as sodium acetate contained in the shelf-life extender are suppressed, and the desirable taste inherent in the food can be maintained. In the first embodiment, the pH of the aqueous solution can be adjusted by adjusting the content of sodium acetate and one or more organic acids, and in the second embodiment, it can be adjusted by adjusting the content of acetic acid. Basically, in the first or second embodiment, the pH of the aqueous solution can be adjusted within the specified range by adjusting the content of these components within the specified range.

[0038] The shelf-life extender of the present invention may contain other components besides the essential components (sodium acetate and organic acid in the first form, acetic acid in the second form, and ginger extract as an essential component common to both forms), provided that the predetermined effects of the present invention are not inhibited. Specific examples of other components used to enhance the shelf-life extender effect include glycine, lysozyme, emulsifiers, and chelating agents. Specific examples of other components used to stabilize the formulation include dextrin, sucrose fatty acid esters, calcium stearate, and glycerin fatty acid esters. In the present invention, one of the other components may be used alone or in combination of two or more.

[0039] The shelf-life extender of the present invention can be manufactured by mixing the above-mentioned components. The shelf-life extender of the present invention is typically a powder or granular substance or a liquid or paste that is fluid at room temperature and atmospheric pressure. In this specification, "room temperature and atmospheric pressure" refers to the ambient temperature and atmospheric pressure of the environment in which the food or shelf-life extender of the present invention is normally manufactured and used (e.g., consumed), and is typically an environment with an ambient temperature of 25°C and an atmospheric pressure of 1 atmosphere.

[0040] The shelf-life extender of the present invention can be used in food in the same way as shelf-life extenders of this type. Methods of using the shelf-life extender of the present invention include adding it to an intermediate product of the food during the food manufacturing process, spraying or coating it onto the finished food product, or immersing the finished food product in the shelf-life extender. When applying the shelf-life extender of the present invention to food, it may also be used in the form of the shelf-life extender dissolved or dispersed in a suitable solvent (e.g., water).

[0041] The food shelf-life extender of the present invention is not particularly limited in terms of the types of foods it can be used in, and can be used in both heat-treated and unheat-treated foods. Specific examples of foods to which the food shelf-life extender of the present invention can be used include prepared foods, seasonings, and wheat-based processed foods.

[0042] The amount of the shelf-life extending agent of the present invention used for food is preferably adjusted such that the content of each component (sodium acetate and an organic acid in the first embodiment, acetic acid in the second embodiment, and ginger extract as an essential component common to both embodiments) in the shelf-life extending agent in the food to which the shelf-life extending agent is applied falls within the same range as that described above for the food of the present invention.

[0043] The present invention includes a method for inhibiting perception of sour taste and acid odor in food containing sodium acetate or an organic acid. The method for inhibiting perception of sour taste and acid odor of the present invention is described below. Only configurations differing from the food and shelf-life extending agent of the present invention described above will be explained for the method for inhibiting perception of sour taste and acid odor of the present invention. For configurations not specifically described in the method for inhibiting perception of sour taste and acid odor of the present invention, the descriptions of the food or shelf-life extending agent of the present invention above apply as appropriate.

[0044] The method for inhibiting perception of sour taste and acid odor of the present invention comprises incorporating ginger extract into food containing sodium acetate or an organic acid (hereinafter also referred to as "bacteriostatic agent-containing food"). This makes it possible to reduce undesirable sour taste and acid odor caused by sodium acetate or an organic acid, and improve the storage stability of food through the bacteriostatic effect of sodium acetate or an organic acid while maintaining the original flavor of food that does not contain sodium acetate and organic acids. The effect of ginger extract in reducing sour taste and acid odor caused by sodium acetate or an organic acid is mainly achieved by so-called masking, which conceals the sour taste and acid odor with the flavor of the ginger extract.

[0045] In the method for inhibiting perception of sour taste and acid odor of the present invention, the amount of ginger extract used for the bacteriostatic agent-containing food is preferably adjusted such that the content of the ginger extract in the bacteriostatic agent-containing food to which the ginger extract is applied falls within the same range as that described above for the food of the present invention.

[0046] The bacteriostatic agent-containing food to which the method for inhibiting perception of sour taste and acid odor of the present invention can be applied is not particularly limited, and the method can be used for both heat-treated food and non-heat-treated food. Specific examples of bacteriostatic agent-containing food to which the method for inhibiting perception of sour taste and acid odor of the present invention can be applied include side dishes, seasonings, and processed wheat foods.

[0047] Hereinafter, the present invention will be described in further detail with reference to Examples, but the present invention is not limited to the following Examples.

[0048] [Production of Shelf Life Improver] Various raw materials shown in Tables 1 and 2 below were mixed to produce powdery and granular shelf life improvers a to e at normal temperature and normal pressure. Details of the raw materials used are as follows. ・Ginger extract: "Ginger Extract Powder" manufactured by Vidya Japan Co., Ltd.

[0049]

[0050] [Examples and Comparative Examples: Production of Foods Containing Shelf Life Improver] The following foods were produced: spinach ohitashi, a type of prepared side dish (simmered dish or dressed dish); carbonara sauce, a type of seasoning (pasta sauce); and hot cake, a type of processed wheat food (bakery product). Any one of the shelf life improvers a to e was added to these three types of foods to produce foods containing the shelf life improver. Examples A1 to A2 and Comparative Examples A1 to A4 produced spinach ohitashi containing the shelf life improver; Examples B1 to B2 and Comparative Examples B1 to B4 produced carbonara sauce containing the shelf life improver; and Examples C1 to C2 and Comparative Examples C1 to C4 produced hot cake containing the shelf life improver. The specific production method for each food is as follows. The blending amounts of raw materials and food compositions during the production of each food are shown in Tables 2 to 4 below.

[0051] (Method for making blanched spinach) 300g of soy sauce (Kikkoman Koikuchi Soy Sauce, manufactured by Kikkoman Corporation), 100g of refined sugar (DM Mitsui Sugar Co., Ltd. "Refined Sugar"), 250g of mirin (Takara Hon Mirin, manufactured by Takara Shuzo Co., Ltd.), 5g of kelp stock (Hondashi Kombu Dashi, manufactured by Ajinomoto Co., Inc.), 5g of bonito stock (Hondashi Katsuo Dashi, manufactured by Ajinomoto Co., Inc.), and 340g of water were measured into a pot and heated to 85°C. Heating was stopped after reaching the desired temperature. After cooling, water was added to compensate for evaporation during heating, bringing the total to 1000g to make the dressing. Frozen spinach was placed in boiling water and boiled. After boiling again, the spinach was removed 2 minutes later and cooled under running water for 1 minute. The water was drained to a yield of about 75%, and this was used as boiled spinach. A shelf-life extender was added to the aforementioned dressing broth to obtain a dressing broth containing a shelf-life extender. This broth was then added in a quantity of 1 part by mass to 10 parts by mass of the boiled spinach and mixed well. Water was added as needed to equalize the total weight in each production example, and the spinach salad with shelf-life extender was prepared.

[0052] (Method for manufacturing carbonara sauce) A shelf-life extender was added to commercially available carbonara sauce ("Ma-Ma Milk-Rich Carbonara Sauce" manufactured by Nisshin Flour Milling Co., Ltd. Welna Co., Ltd.) and mixed. Water was added as needed to equalize the total weight in each manufacturing example, and carbonara sauce with a shelf-life extender was produced.

[0053] (Method for making pancakes) One egg and 140 ml of water were placed in a bowl and mixed well with a whisk. 200 g of commercially available pancake mix (Nisshin Hotcake Mix with Zipper, manufactured by Nisshin Flour Milling Co., Ltd.) and a shelf-life extender were added and mixed well with a whisk. Water was added as needed to equalize the total weight in each production example, and the mixture was thoroughly mixed to make the pancake batter. The batter was poured into a heated frying pan and heated over low heat for about 3 minutes. The pancakes were then flipped over and heated over low heat for about 2 minutes to produce pancakes with a shelf-life extender.

[0054] [Evaluation Test 1] The bacteriostatic properties of the foods containing shelf-life extenders produced in the examples and comparative examples were evaluated. Specifically, a method corresponding to the type of food being evaluated was selected from the various food evaluation methods listed below, and the bacteriostatic properties were evaluated according to the selected evaluation method. Bacteriostatic properties were evaluated using the number of growing bacteria as an indicator, with A (highest evaluation) given when the maximum number of growing bacteria was less than 2.0 LOGcfu / g, B given when the maximum number was 2.0 LOGcfu / g or more but less than 3.0 LOGcfu / g, and C given when the maximum number was 3.0 LOGcfu / g or more. The results are shown in Tables 2 to 4 below.

[0055] (Method for evaluating the bacteriostatic properties of blanched spinach) Blanched spinach to be evaluated was inoculated with approximately 50 cfu / g of lactic acid bacteria Leuconostoc mesenteroides, and then left to stand for 96 hours in an environment with an ambient temperature of 10°C. The blanched spinach after inoculation with lactic acid bacteria was diluted 10-fold with peptone water to obtain a sample solution, and this sample solution was diluted as appropriate and spread on a standard agar plate to measure the number of viable cells. The number of viable cells was measured by the surface smear method. Specifically, it was as follows: 0.1 mL of the sample solution or 0.1 mL of a diluted sample solution obtained by diluting the sample solution 10-fold or 100-fold was dropped onto the surface of a pre-solidified agar plate, spread evenly with a Conlarger rod, and cultured. Aerobic culture at 30°C for 48 hours using a standard agar plate was adopted as the culture medium and culture conditions. The number of viable cells was measured by multiplying the number of colonies grown in the culture medium by the dilution factor to obtain the number of viable cells per gram of culture medium (LOGcfu / g). The number of cells was converted to a logarithm, and the initial number of cells was subtracted to calculate the number of cells that had grown.

[0056] (Method for evaluating the bacteriostatic properties of carbonara sauce) Approximately 200 cfu / g of Bacillus cereus spores were inoculated into the carbonara sauce to be evaluated, and it was left to stand for 24 hours in an environment with an ambient temperature of 35°C. The carbonara sauce after inoculation with Bacillus cereus was diluted 10-fold with peptone water to obtain a sample solution, and this sample solution was diluted as appropriate and spread on a standard agar plate to measure the number of viable cells. The number of viable cells was measured by the surface smear method. Specifically, it was as follows: 0.1 mL of the sample solution or 0.1 mL of a diluted sample solution obtained by diluting the sample solution 10-fold or 100-fold was dropped onto the surface of the agar plate that had been pre-solidified into a plate, and it was spread evenly with a convection rod and cultured. Aerobic culture at 35°C for 24 hours using a standard agar medium was adopted as the culture medium and culture conditions. The number of viable cells was measured by multiplying the number of colonies grown in the culture medium by the dilution factor to obtain the number of viable cells per gram of culture medium (LOGcfu / g). The number of cells was converted to a logarithm, and the initial number of cells was subtracted to calculate the number of cells that had grown.

[0057] (Method for evaluating the bacteriostatic properties of pancakes) Approximately 200 cfu / g of Bacillus cereus spores were inoculated into the pancakes to be evaluated, and then left to stand for 9 hours in an environment with an ambient temperature of 30°C. The pancakes inoculated with Bacillus cereus were diluted 10-fold with peptone water to obtain a sample solution, and this sample solution was diluted as appropriate and spread onto standard agar plates to measure the number of viable cells. The number of viable cells was measured by the surface smear method. Specifically, it was as follows: 0.1 mL of the sample solution or 0.1 mL of a diluted sample solution obtained by diluting the sample solution 10-fold or 100-fold was dropped onto the surface of agar plates that had been pre-solidified, and the mixture was spread evenly with a convection wand and cultured. Aerobic culture at 35°C for 24 hours using standard agar medium was adopted as the culture medium and culture conditions. The number of viable cells was measured by multiplying the number of colonies grown in the culture medium by the dilution factor to obtain the number of viable cells per gram of culture medium (LOGcfu / g).

[0058] [Evaluation Test 2] The flavor and appearance of the foods containing shelf-life extenders produced in the examples and comparative examples were evaluated. Specifically, five expert panelists tasted the foods to be evaluated and evaluated them according to the following criteria. The arithmetic mean of the five panelists' evaluation scores was used as the evaluation result for the food. The results are shown in Tables 2 to 4 below.

[0059] <Flavor Evaluation Criteria> 5 points: No sourness or sour odor detected, extremely good. 4 points: Slight sourness or sour odor detected, good. 3 points: Sourness or sour odor detected, but within acceptable limits. 2 points: Strong sourness or sour odor detected, poor. 1 point: Very strong sourness or sour odor detected, extremely poor. <Appearance Evaluation Criteria> These evaluation criteria are used when comparing the product being evaluated to a food with the same composition as the product being evaluated, except that it does not contain shelf-life extenders. 5 points: No change in color or viscosity detected, extremely good. 4 points: Almost no change in color or viscosity detected, good. 3 points: Slight change in color or viscosity detected, within acceptable limits. 2 points: Change in color or viscosity detected, poor. 1 point: Significant change in color or viscosity, extremely poor.

[0060]

[0061]

[0062]

[0063] As shown in Tables 2 to 4, the food products of each example contained 0.2 to 2% by mass of sodium acetate and 0.01 to 0.2% by mass of organic acid (citric acid), and also contained 0.005 to 0.1% by mass of ginger extract. Therefore, compared to the comparative examples that did not meet these criteria, they all received high marks for bacteriostatic properties, flavor, and appearance. Industrial applicability

[0064] The food of the present invention has excellent preservation properties because it contains a bacteriostatic component, and the original flavor of the food is less likely to be impaired by the component, resulting in a good flavor. Furthermore, the food preservation agent of the present invention can improve the preservation of food without impairing the original flavor of the food. In addition, the method for inhibiting the perception of sour taste and sour odor of the present invention makes it difficult to perceive the sour taste and sour odor caused by organic acids (sodium acetate or organic acids) that exhibit bacteriostatic effects in food, thus maintaining the original flavor of the food.

Claims

1. A food product containing 0.2 to 2% by mass of sodium acetate and 0.01 to 0.2% by mass of an organic acid, or 0.02 to 0.2% by mass of acetic acid, and 0.005 to 0.1% by mass of ginger extract, with a pH of 5.0 to 7.0 at a product temperature of 25°C.

2. The food according to claim 1, wherein the organic acid comprises at least one selected from the group consisting of acetic acid, citric acid, malic acid, fumaric acid, adipic acid, glucono delta-lactone, gluconic acid, succinic acid, tartaric acid, ascorbic acid, and lactic acid.

3. The food according to claim 1 or 2, which is rice, prepared food, seasoning, or wheat processed food.

4. A food preservative containing 40-90% by mass of sodium acetate and 1-15% by mass of an organic acid, or 3-15% by mass of acetic acid, and 0.3-0.9% by mass of ginger extract, wherein the pH of a 1% by mass aqueous solution at a product temperature of 25°C is 4.0-6.

0.

5. The food shelf-life extender according to claim 4, wherein the organic acid comprises at least one selected from the group consisting of acetic acid, citric acid, malic acid, fumaric acid, adipic acid, glucono delta-lactone, gluconic acid, succinic acid, tartaric acid, ascorbic acid, and lactic acid.

6. A method for inhibiting the perception of sour taste and sour odor in a food containing sodium acetate or an organic acid, comprising including ginger extract in the food.

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