Improved fermented food and its manufacturing method

Abstract

To provide an improved fermented food with good flavor and method for producing the same in which unpleasant odor and acid taste due to fermentation are suppressed and umami-taste due to fermentation is enhanced, and to provide a method for improving flavor of fermented food.SOLUTION: To a fermented food, a flavor improvement agent for fermented food that contains triacylglycerol, which has, as constituent fatty acid, medium-chain fatty acid of 6 to 12 carbon atoms, as an active ingredient, is added. The constituent fatty acid of the triacylglycerol having medium-chain fatty acid preferably comprises only medium-chain fatty acid having 6 to 12 carbon atoms, and more preferably comprises only medium-chain fatty acid having 8 and / or 10 carbon atoms.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an improved fermented food having an improved flavor. More specifically, the present invention relates to an improved fermented food having a good flavor in which unpleasant odors and sourness due to fermentation are suppressed and the umami taste due to fermentation is enhanced, and a method for producing the same. The present invention also relates to a method for improving the flavor of fermented foods. [Background technology]

[0002] In recent years, consumers have become increasingly concerned about the health of their food. In addition, there is a growing need for health foods that can be easily eaten every day, especially among the elderly. Fermented foods are foods that are processed by fermenting ingredients through the action of microorganisms. Fermentation produces glutamic acid and inosinic acid, which are the source of umami, and in addition to the original taste of the food, a unique flavor is added, making the food more flavorful. Fermentation also increases beneficial ingredients, making the food more nutritious. Furthermore, lactic acid bacteria produce lactic acid from sugars such as vegetables, which inhibits the growth of miscellaneous bacteria and makes the food more shelf-stable. In addition, fermented foods contain many live beneficial bacteria, which contribute to health by improving the intestinal environment. Recently, it has been discovered that glutamic acid and histidine, which are contained in large quantities in fermented foods, have anti-obesity functions. Fermented foods have long been a part of the Japanese diet, so they are one of the foods that people can continue to eat every day without getting tired of them. In addition, multiple fermented foods can be combined and eaten, so it is easy to create health foods that suit your eating needs. Therefore, fermented foods can be said to be one of the health foods that can be easily eaten every day.

[0003] Among fermented foods, there are soybean fermented foods made from soybeans. Soybeans contain functional ingredients such as isoflavones, soybean oligosaccharides, and saponins. Representative examples of soybean fermented foods include miso, soy sauce, and natto. It is also known that various functional ingredients are produced by fermentation. For example, melanoidin produced during the manufacturing process of miso and soy sauce is known to have antioxidant properties. In addition, nattokinase is known to have a thrombolytic effect in natto. Note that while miso and soy sauce are salted soybean fermented foods, natto is a salt-free soybean fermented food. On the other hand, soybean fermented foods have problems such as bean odor, grassy odor, and astringency derived from soybeans, and also have problems such as a fermented odor derived from fermentation, so it is difficult to say that soybean fermented foods are suitable for everyone. Therefore, many studies have been conducted to reduce the bean odor, grassy odor, astringency, etc., specific to soybeans using various food additives. For example, Patent Document 1 proposes a technology to reduce the grassy odor and astringency specific to soybeans by adding triacylglycerol having medium-chain fatty acids with 6 to 12 carbon atoms as constituent fatty acids to soy milk. In addition, Patent Document 2 proposes a technology to reduce the grassy odor and astringency specific to soybeans by adding triacylglycerol having medium-chain fatty acids with 6 to 12 carbon atoms as constituent fatty acids to soybean flour. However, these prior art technologies do not specifically disclose that the addition of triacylglycerol having medium-chain fatty acids with 6 to 12 carbon atoms as constituent fatty acids to fermented soybean foods made by fermenting soybeans as a raw material suppresses unpleasant odors and sourness caused by fermentation, enhances the umami taste caused by fermentation, and results in a good flavor.

[0004] Among fermented foods, there are lactic acid fermented foods that are fermented with lactic acid bacteria. Lactic acid bacteria are widely found in nature and are distributed in various foods. Representative examples of lactic acid fermented foods include yogurt, cheese, pickles, kimchi, miso, and soy sauce. In yogurt, lactic acid bacteria inhibit the growth of harmful microorganisms, increase the safety and shelf life of yogurt, and contribute to health by improving the intestinal environment. In cheese, lactic acid bacteria lower the pH, help the milk protein to aggregate, and impart a moderate acidity. In pickles and kimchi, lactic acid bacteria foster a unique flavor and impart shelf life. Furthermore, in miso and soy sauce, lactic acid bacteria are said to have the effect of masking the odor of ingredients such as soybeans, improving salt tolerance and color clarity. On the other hand, some lactic acid fermented foods have unpleasant odors, off-flavors, sourness, etc., derived from lactic acid bacteria and lactic acid fermentation, and are therefore not suitable for everyone. Therefore, many studies have been conducted to reduce the unpleasant odors, off-flavors, and sourness derived from lactic acid bacteria and lactic acid fermentation using various food additives. For example, Patent Document 3 proposes an off-flavor masking agent that contains calcium and / or magnesium as an active ingredient, as a masking agent for the off-flavor derived from lactic acid bacteria in lactic acid bacteria-containing beverages. However, these prior art technologies do not specifically disclose that the addition of triacylglycerol having a medium-chain fatty acid with 6 to 12 carbon atoms as a constituent fatty acid to a lactic acid fermented food fermented with lactic acid bacteria suppresses unpleasant odors and sourness derived from lactic acid bacteria and lactic acid fermentation, enhances the umami taste due to fermentation, and results in a good flavor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2015 / 072570 [Patent Document 2] International Publication No. 2015 / 129107 [Patent Document 3] JP 2017-209090 A Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide an improved fermented food having a good flavor in which unpleasant odors and sourness due to fermentation are suppressed and the umami taste due to fermentation is enhanced, a method for producing the same, and a method for improving the flavor of fermented foods. [Means for solving the problem]

[0007] The present inventors have carried out intensive research into whether or not unpleasant odors and sourness caused by fermentation can be suppressed by adding various oils and fats to fermented foods, and have found that the problem can be solved by blending a specific amount of triacylglycerol having a medium-chain fatty acid having 6 to 12 carbon atoms, thereby completing the present invention. They have also found that the umami taste caused by fermentation is enhanced, thereby completing the present invention. That is, the present invention can be in the following aspects.

[0008] [1] For fermented foods containing triacylglycerol with medium-chain fatty acids having 6 to 12 carbon atoms as the active ingredient Fermentation Odor suppressant an agent for improving an unpleasant odor caused by fermentation for fermented foods, wherein the constituent fatty acids of the triacylglycerol having medium-chain fatty acids are composed only of medium-chain fatty acids having 8 and / or 10 carbon atoms, the fermented food is one or more selected from the group consisting of miso, soy sauce, natto, yogurt, and kimchi, and the content of the triacylglycerol having medium-chain fatty acids is 0.5 to 15 parts by mass per 100 parts by mass of the fermented food. . [2] Fermented food and the method for producing the fermented food according to claim 1. Fermentation An improved fermented food containing an unpleasant odor improving agent and having an improved flavor The improved fermented food contains 0.5 to 15 parts by mass of the unpleasant odor improving agent per 100 parts by mass of the fermented food. . [3] A method for producing an improved fermented food in which unpleasant odors due to fermentation are suppressed, the method comprising the step of mixing a fermented food with a triacylglycerol having a medium-chain fatty acid having 6 to 12 carbon atoms as a constituent fatty acid such that the content of the triacylglycerol having the medium-chain fatty acid is 0.5 to 15 parts by mass per 100 parts by mass of the fermented food. The method for producing an improved fermented food, wherein the constituent fatty acids of the triacylglycerol having medium-chain fatty acids are composed only of medium-chain fatty acids having 8 and / or 10 carbon atoms, and the fermented food is one or more selected from the group consisting of miso, soy sauce, natto, yogurt, and kimchi. . [4] A method for improving an unpleasant odor caused by fermentation of a fermented food, comprising a step of mixing a fermented food with a triacylglycerol having a medium-chain fatty acid having 6 to 12 carbon atoms as a constituent fatty acid such that the content of the triacylglycerol having the medium-chain fatty acid is 0.5 to 15 parts by mass per 100 parts by mass of the fermented food. a method for improving an unpleasant odor caused by fermentation of a fermented food, the constituent fatty acids of the triacylglycerol having medium-chain fatty acids being composed only of medium-chain fatty acids having 8 and / or 10 carbon atoms, and the fermented food being one or more selected from the group consisting of miso, soy sauce, natto, yogurt, and kimchi. . Effect of the Invention

[0009] According to the present invention, by adding a specific amount of triacylglycerol having medium-chain fatty acids with 6 to 12 carbon atoms to a fermented food, anyone can easily produce an improved fermented food with good flavor, in which unpleasant odors and sourness caused by fermentation are suppressed and the umami taste caused by fermentation is enhanced. The improved fermented food of the present invention has a good flavor in which unpleasant odors and sourness caused by fermentation are suppressed and the umami taste caused by fermentation is enhanced, so that it can satisfy the demand of people who have not been satisfied with conventional fermented foods. In particular, it can be eaten by consumers who have not been good at fermented foods, so that an increase in demand can be expected. In addition, since it contains triacylglycerol having medium-chain fatty acids, it can be easily eaten every day as a health food for effective energy supply for the elderly or during exercise, or as a health food for exerting the physiological effects of medium-chain fatty acids. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Flavor improver for fermented foods] One aspect of the present invention is a flavor improver for fermented foods, the active ingredient of which is triacylglycerol having a medium-chain fatty acid with 6 to 12 carbon atoms as a constituent fatty acid. The flavor improver will be described below. The flavor improver improves the flavor of fermented foods, and can be used, for example, to suppress unpleasant odors and sourness caused by fermentation and to enhance the umami taste caused by fermentation.

[0011] [Constituent fatty acids] The flavor improver for fermented foods of the present invention contains triacylglycerol (i.e., fats and oils) having medium-chain fatty acids with 6 to 12 carbon atoms as constituent fatty acids. The number of carbon atoms of the medium-chain fatty acids is more preferably 8 to 12, and even more preferably 8 and / or 10. The triacylglycerol may be a triacylglycerol whose constituent fatty acids are only medium-chain fatty acids with 6 to 12 carbon atoms, more preferably 8 to 12, and even more preferably 8 and / or 10 carbon atoms. Furthermore, it may be a mixed-acid triacylglycerol containing medium-chain fatty acids with 6 to 12 carbon atoms and other fatty acids as constituent fatty acids. Here, the binding position of each medium-chain fatty acid to glycerin is not particularly limited. In addition, in the case of a mixed-acid triacylglycerol, some of the constituent fatty acids may contain fatty acids other than those with 6 to 12 carbon atoms, and may contain, for example, long-chain fatty acids with 14 or more carbon atoms. The triacylglycerol having a medium-chain fatty acid used in the present invention may be a mixture of oils and fats of different molecular species, such as a mixture of trioctanoylglycerol and tridecanoylglycerol, and may be in any form, such as liquid, solid, or powder. Here, the medium-chain fatty acid having 6 to 12 carbon atoms is preferably a linear saturated fatty acid.

[0012] As the triacylglycerol having medium-chain fatty acids that can be used in the present invention, triacylglycerols (hereinafter also referred to as "MCT") whose constituent fatty acids are composed only of medium-chain fatty acids having 6 to 12 carbon atoms are preferred, and in particular, triacylglycerols whose constituent fatty acids are composed only of medium-chain fatty acids having 8 and / or 10 carbon atoms are more preferred. The triacylglycerol having a medium-chain fatty acid that can be used in the present invention can be produced by a conventionally known method, for example, by heating a fatty acid having 6 to 12 carbon atoms and glycerol in the presence of a catalyst, preferably in the absence of a catalyst, and preferably under reduced pressure at 50 to 250°C, more preferably 120 to 180°C, to cause dehydration condensation. The catalyst is not particularly limited, and may be, for example, an acid catalyst or a base catalyst used in normal ester exchange. The reduced pressure is, for example, 0.01 to 100 Pa, preferably 0.05 to 75 Pa, and more preferably 0.1 to 50 Pa. In this case, the water content in the system is preferably low, and more preferably 0.2% by weight or less.

[0013] The flavor improving agent for fermented foods of the present invention may contain triacylglycerol having a medium-chain fatty acid having 6 to 12 carbon atoms as described above as an active ingredient, and may also contain other ingredients, i.e., for example, fats and oils such as soybean oil and rapeseed oil, excipients such as dextrin and starch, other quality improving agents, etc., within the scope that does not impair the effects of the present invention.

[0014] [Improved fermented foods] A preferred embodiment of the present invention includes an improved fermented food having an improved flavor, which comprises a fermented food and the above-mentioned flavor improving agent for fermented foods. In the present invention, the term "fermented food" refers to food processed by fermenting ingredients by the action of microorganisms. There are various types of fermented food, such as processed grain products (natto, miso, soy sauce, etc.), processed seafood products (dried bonito, salted fish, etc.), processed vegetable and fruit products (pickles, kimchi, etc.), dairy products (yogurt, cheese), alcoholic beverages (sake, wine, beer, etc.), and teas (black tea, oolong tea, etc.), but the fermented food of the present invention is preferably a soybean fermented food or a lactic acid fermented food. More specific preferred examples include one or more types selected from the group consisting of miso, soy sauce, natto, yogurt, cheese, pickles, and kimchi. Further preferred examples include one or more types selected from the group consisting of miso, soy sauce, and natto.

[0015] The improved fermented food of the present invention contains the fermented food and the flavor improver for fermented foods. In particular, it is suitable that the triacylglycerol having a medium-chain fatty acid having 6 to 12 carbon atoms contained in the flavor improver for fermented foods is, for example, 0.5 to 15 parts by mass relative to 100 parts by mass of the fermented food. Therefore, the content of the triacylglycerol contained in the improved fermented food of the present invention is preferably 1 to 10 parts by mass, more preferably 1 to 8 parts by mass, and even more preferably 1.5 to 7 parts by mass relative to 100 parts by mass of the fermented food. If the amount exceeds 20 parts by mass, the amount of fat and oil relative to the fermented food may be too large, making it unsuitable for consumption. When the content of triacylglycerol having medium-chain fatty acids having 6 to 12 carbon atoms contained in the improved fermented food is within the above range, unpleasant odors and sourness caused by fermentation are suppressed, and an improved fermented food with a good flavor and enhanced umami due to fermentation is obtained, which is preferable. Note that, in the present invention, even if the content is less than the above-mentioned 0.5 parts by mass, it is believed that the effect of suppressing unpleasant odors and sourness caused by fermentation can be expected to a certain extent.

[0016] The improved fermented food of the present invention may further contain any other oil and fat raw material, so long as it contains a suitable amount of triacylglycerol having a medium-chain fatty acid having 6 to 12 carbon atoms. For example, the improved fermented food of the present invention may further contain coconut oil, palm kernel oil, palm oil, palm fractionated oil (palm olein, palm superolein, etc.), shea butter, shea fractionated oil, monkey fat, monkey fractionated oil, illipe fat, soybean oil, rapeseed oil, cottonseed oil, safflower oil, sunflower oil, rice oil, corn oil, sesame oil, olive oil, milk fat, cocoa butter, etc., or mixtures or processed oils and fats thereof.

[0017] The improved fermented food of the present invention may contain, in addition to the above-mentioned triacylglycerol, ingredients that are generally blended into fermented foods, such as sugars, sweeteners, acidulants, salts, minerals, stabilizers, pH adjusters, thickening polysaccharides, emulsifiers, fragrances, flavors, colorants, etc.

[0018] [Method of producing improved fermented foods] The method for producing the improved fermented food of the present invention will be described step by step below. The method for producing an improved fermented food of the present invention includes a step of using the above-mentioned fermented food as a raw material and mixing the fermented food with a triacylglycerol having a medium-chain fatty acid having 6 to 12 carbon atoms as a constituent fatty acid such that the content of the triacylglycerol having the medium-chain fatty acid is 0.5 to 15 parts by mass per 100 parts by mass of the fermented food. Here, the definitions and preferred ranges of the fermented food as the raw material, the triacylglycerol having a medium-chain fatty acid with 6 to 12 carbon atoms, and the content of the triacylglycerol having the medium-chain fatty acid are as described above. The fermented food of the present invention and triacylglycerol having a medium-chain fatty acid with 6 to 12 carbon atoms can be mixed according to a conventional method. For example, a fermented food is prepared according to a conventional method. Then, the above-mentioned triacylglycerol having a medium-chain fatty acid is added to this fermented food, and the two are thoroughly stirred and mixed to produce a fermented food in which the triacylglycerol is well dispersed. The well-dispersed state may be an emulsified state. Here, the mixing temperature may be about room temperature (25°C), and the stirring and mixing may be performed using a mixer or the like that is normally used for stirring, or may be performed by hand using chopsticks or a spoon.

[0019] [Methods for improving the flavor of fermented foods] As described above, when triacylglycerol having a medium chain fatty acid with 6 to 12 carbon atoms is added to a fermented food, the unpleasant odor and sourness caused by fermentation are suppressed, and the deliciousness caused by fermentation is enhanced, so that the fermented food can be modified to have a good flavor. Therefore, the present invention also relates to a method for improving the flavor of a fermented food, which includes a step of mixing a fermented food with triacylglycerol having a medium chain fatty acid with 6 to 12 carbon atoms as a constituent fatty acid so that the content of the triacylglycerol having the medium chain fatty acid is 0.5 to 15 parts by mass per 100 parts by mass of the fermented food. As shown below, by using the flavor improver for fermented foods of the present invention in the production of an improved fermented food, a conventional fermented food can be improved to one having a good flavor in which the unpleasant odor and sourness caused by fermentation are suppressed and the deliciousness caused by fermentation is enhanced. Here, the definitions and preferred ranges of the fermented food, the triacylglycerol having a medium chain fatty acid with 6 to 12 carbon atoms used as the raw material, and the content of the triacylglycerol having the medium chain fatty acid are as described above. EXAMPLES

[0020] EXAMPLES Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these in any way.

[0021] The triacylglycerol composition of the oils and fats was analyzed by gas chromatography (in accordance with JAOCS, vol. 70, 11, 1111-1114 (1993)). The constituent fatty acids of the oils and fats were analyzed using gas chromatography (in accordance with AOCS Ce1f-96).

[0022] <Raw material oil> [MCT]: The fatty acids constituting the triacylglycerol were octanoic acid (8 carbon atoms) and decanoic acid (10 carbon atoms), and the ratio (mass ratio) of the fatty acids constituting the triacylglycerol was octanoic acid:decanoic acid = 75:25. Triacylglycerol (manufactured by Nisshin Oillio Group, Ltd., product name "ODO") composed only of medium-chain fatty acids with 8 and 10 carbon atoms was used as MCT. [Canola oil]: The fatty acids constituting triacylglycerols are palmitic acid (carbon number 16), oleic acid (carbon number 18), linoleic acid (carbon number 18), and others, and the ratio (mass ratio) of fatty acids constituting triacylglycerols is palmitic acid:oleic acid:linoleic acid:others = approximately 4:61:20:15. Canola oil was used as the canola oil (manufactured by Nisshin Oillio Group, Ltd., product name "Nissin Canola Oil").

[0023] <Raw fermented food> [Miso]: Manufactured by Marusanai Co., Ltd., product name "Junsei Koji Miso" [Soy sauce]: Kikkoman Corporation, product name "Always Freshly Squeezed Raw Soy Sauce" [Natto]: Takano Foods Co., Ltd., product name: "Mini 3" [Yogurt]: Made by Meiji Co., Ltd., product name "Meiji Bulgaria Yogurt" [Kimchi]: Made by Miyama Co., Ltd., product name: "Recommended Yakiniku Restaurant Taste Kimchi"

[0024] [Examples 1 to 5] The raw fermented food was dispensed into test tubes at 50 g. The MCT was then added to the test tubes at 0 parts by mass (control), 1 part by mass, 10 parts by mass, and 20 parts by mass per 100 parts by mass of the raw fermented food. The mixture was thoroughly stirred with a spoon to produce the test fermented food. Note that the food that was prone to separation was eaten immediately after stirring and mixing. Example 1 is miso, Example 2 is soy sauce, Example 3 is natto, Example 4 is yogurt, and Example 5 is kimchi.

[0025] [Comparative Examples 1 to 5] The fermented food was dispensed into a test tube at 50 g. The canola oil was added to the test tube at 0 parts by mass (control), 1 part by mass, 10 parts by mass, and 20 parts by mass per 100 parts by mass of the fermented food. The mixture was thoroughly stirred with a spoon to produce a test fermented food. Note that the food that was prone to separation was eaten immediately after stirring and mixing. Comparative Examples 1 to 5 are the same as Examples 1 to 5.

[0026] [Sensory evaluation] The test fermented foods (room temperature: 25°C) obtained above were subjected to a sensory evaluation by five panelists who had passed the in-house taste test and smell test (using standard odors for panel selection manufactured by Daiichi Yakuhin Sangyo Co., Ltd.). The results are shown in Tables 1 to 10. The evaluation was performed using a control containing 0 parts by mass of MCT or canola oil, and a higher score indicates a better product. The scores are the average of the scores of the five panelists. When the fermented food was miso (Tables 1-2), unpleasant odor, saltiness, and umami were evaluated using a 3-point scale, and the overall flavor was evaluated using a 5-point scale. When the fermented food was soy sauce (Tables 3-4), unpleasant odor, saltiness, and umami were evaluated using a 3-point scale, and flavor was evaluated overall using a 5-point scale. When the fermented food was natto (Tables 5-6), unpleasant odor, off-flavor (bitterness, harshness), and umami were evaluated using a 3-point scale, and flavor was evaluated overall using a 5-point scale. When the fermented food was yogurt (Tables 7-8), unpleasant odor, sourness, and umami were evaluated using a 3-point scale, and flavor was evaluated overall using a 5-point scale. When the fermented food was kimchi (Tables 9-10), unpleasant odor, sourness, and umami were evaluated using a 3-point scale, and flavor was evaluated overall using a 5-point scale. <In case of unpleasant odor> 3 points: The unpleasant odor is suppressed more than the control product. 2 points: Equivalent to the control product (raw fermented food) 1 point: The odor is worse than the control product. <Salty, strange or sour taste> 3 points: The saltiness, off-flavors, and sourness are reduced compared to the control product. 2 points: Equivalent to the control product (raw fermented food) 1 point: Worse than the control product, with a saltier, stranger, or sourer taste <In the case of umami> 3 points: The flavor is enhanced more than the control product. 2 points: Equivalent to the control product (raw fermented food) 1 point: The flavor is less than the control product and is poor. <Overall evaluation (flavor)> 5 points: Better flavor than the control and tastier 4 points: Slightly better flavor than the control 3 points: Equivalent to the control product (raw fermented food) 2 points: The flavor is slightly worse than the control product. 1 point: The flavor is worse than the control product and it is not tasty.

[0027] [Table 1]

[0028] [Table 2]

[0029] [Table 3]

[0030] [Table 4]

[0031] [Table 5]

[0032] [Table 6]

[0033] [Table 7]

[0034] [Table 8]

[0035] [Table 9]

[0036] [Table 10]

[0037] As is clear from the results in Tables 1 and 2 above, the improved miso with added MCT had a suppressed unpleasant odor (miso odor) compared to the miso with added canola oil. Also, the improved miso with added MCT had a mellow salty taste, enhanced umami, and an overall mild and pleasant flavor. On the other hand, the miso with added canola oil did not have a mellow salty taste, and was perceived as more salty than the control product. In this way, the improved miso had a good flavor with the unpleasant odor caused by fermentation suppressed, the saltiness suppressed, and the umami taste enhanced.

[0038] As is clear from the results in Tables 3 and 4 above, the improved soy sauce with added MCT had a slightly suppressed unpleasant odor (soy sauce smell) compared to the miso with added canola oil. The improved soy sauce with added MCT also had a slightly stronger umami taste, with the saltiness removed without compromising the original taste of soy sauce. Overall, it had a mild and good flavor. On the other hand, the soy sauce with added canola oil had a slightly stronger saltiness, with the saltiness not removed. However, it seemed that canola oil was a better match for soy sauce compared to miso. Thus, the improved soy sauce had a good flavor with the unpleasant odor caused by fermentation suppressed, the saltiness suppressed, and the umami taste enhanced.

[0039] As is clear from the results of Tables 5 and 6 above, the improved natto with added MCT had a suppressed unpleasant odor (natto odor) compared to the natto with added canola oil. Also, the improved natto with added MCT had a reduced bitterness and harshness derived from soybeans (hereinafter collectively referred to as "off-flavors") compared to the natto with added canola oil. In this way, the improved natto had suppressed unpleasant odors and off-flavors, resulting in natto with enhanced umami and good flavor. Furthermore, when oil and fat are added to natto, the oil and fat act as a release agent, so the natto does not form strings even when stirred, but forms clumps that are easy to eat. It was also confirmed that the remaining natto does not stick to the container, making it easier to clean the container.

[0040] As is clear from the results of Tables 7 and 8 above, the improved yogurt with added MCT had a suppressed unpleasant odor (milky odor) derived from yogurt compared to the yogurt with added canola oil. The improved yogurt with added MCT also masked the sourness derived from yogurt to a moderate extent compared to the yogurt with added canola oil. Furthermore, the improved yogurt with added MCT had a stronger creamy richness and enhanced umami compared to the yogurt with added canola oil. Such enhanced umami was felt even at low MCT concentrations. Thus, in the improved yogurt, unpleasant odors were suppressed, excess sourness was reduced, and the rich, creamy flavor was enhanced, resulting in yogurt with a good flavor.

[0041] As is clear from the results in Tables 9 and 10, the improved kimchi with added MCT had a suppressed unpleasant odor (kimchi odor) compared to the kimchi with added canola oil. The grassy odor derived from the vegetables also seemed to be somewhat suppressed. The improved kimchi with added MCT also seemed to have a suppressed excessive sourness, a mellowed out sharpness of the hotness derived from the chili peppers, and an enhanced umami flavor compared to the kimchi with added canola oil. In this way, the improved kimchi suppresses the unpleasant odor caused by fermentation, and also reduces excessive sourness and spiciness, allowing the original umami flavor of kimchi to be felt, resulting in a milder, more pleasant-tasting kimchi. Furthermore, the improved kimchi has less of an unpleasant odor and a less spicy taste, so even people who don't like kimchi can eat it. It is also expected that people will have less bad breath after eating kimchi.

[0042] In summary, adding an appropriate amount of triacylglycerol having medium-chain fatty acids with 6 to 12 carbon atoms as constituent fatty acids to fermented foods can suppress unpleasant raw material odors and fermentation odors and enhance umami. It was also found that the sourness and other unpleasant flavors caused by fermentation are suppressed and harsh tastes such as saltiness and spiciness are tamed, making it easier to feel the inherent umami of the fermented food. As a result, an improved fermented food with a better flavor than conventional fermented foods was obtained.

Claims

1. A fermentation-based unpleasant odor improver for fermented foods, containing as an active ingredient triacylglycerol having medium-chain fatty acids with 6 to 12 carbon atoms, wherein the constituent fatty acids of the triacylglycerol having medium-chain fatty acids are composed of only medium-chain fatty acids with 8 and / or 10 carbon atoms, the fermented foods are one or more selected from the group consisting of miso, soy sauce, natto, yogurt, and kimchi, and the content of the triacylglycerol having medium-chain fatty acids is 0.5 to 15 parts by mass with respect to 100 parts by mass of the fermented foods.

2. An improved fermented food containing one or more fermented foods selected from the group consisting of miso, soy sauce, natto, yogurt, and kimchi and the fermentation-based unpleasant odor improver for fermented foods according to Claim 1, wherein the unpleasant odor caused by fermentation is suppressed by the unpleasant odor improver and the flavor is improved, and the improved fermented food contains 0.5 to 15 parts by mass of the unpleasant odor improver with respect to 100 parts by mass of the fermented foods.

3. A method for producing an improved fermented food with suppressed unpleasant odor caused by fermentation, comprising a step of mixing a fermented food and triacylglycerol having medium-chain fatty acids with 6 to 12 carbon atoms as constituent fatty acids so that the content of the triacylglycerol having medium-chain fatty acids is 0.5 to 15 parts by mass with respect to 100 parts by mass of the fermented food, wherein the constituent fatty acids of the triacylglycerol having medium-chain fatty acids are composed of only medium-chain fatty acids with 8 and / or 10 carbon atoms, and the fermented food is one or more selected from the group consisting of miso, soy sauce, natto, yogurt, and kimchi.

4. A method for improving the unpleasant odor caused by fermentation of a fermented food, comprising a step of mixing a fermented food and triacylglycerol having medium-chain fatty acids with 6 to 12 carbon atoms as constituent fatty acids so that the content of the triacylglycerol having medium-chain fatty acids is 0.5 to 15 parts by mass with respect to 100 parts by mass of the fermented food, wherein the constituent fatty acids of the triacylglycerol having medium-chain fatty acids are composed of only medium-chain fatty acids with 8 and / or 10 carbon atoms, and the fermented food is one or more selected from the group consisting of miso, soy sauce, natto, yogurt, and kimchi. ​ ​ ​

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