JP2022060682A - Flavor improving agent and novel acetoxy fatty acid ethyl ester which has flavor improving effects - Google Patents

Abstract

To provide a flavor improving agent capable of improving flavors of food and beverage, a novel compound with the flavor improving effects and a production method of the novel compound.SOLUTION: A flavor improving agent contains acetoxy fatty acid ethyl ester which is a lactone ring-opened compound with a specific number of carbon atoms. The flavor improving agent is capable of improving flavors of food and beverage without affecting original flavors of food and beverage. Also, by means of a production method, it becomes easy to produce a novel acetoxy fatty acid ethyl ester with the effects.SELECTED DRAWING: None

Description

The present invention relates to a flavor improving agent and a novel acetoxy fatty acid ethyl ester having a flavor improving effect.

In recent years, with the diversification of foods, various flavor-improving agents have been demanded. , Erythritol and / or a citrus acidity enhancer containing sorbitol as an active ingredient (Patent Document 3) and the like have been proposed. However, the proposals mentioned above were not always satisfactory in terms of taste.

There is also a flavor improver using a lactone used for food flavors, a roasted taste beverage or a roasted taste beverage flavored food and drink finish improving agent (Patent Document 4), and a fruit juice feeling and a body feeling are imparted by wine lactone (Patent). Document 5), a combination of flufuryl alcohol and γ-butyrolactone to give a drink response and body feeling from the middle to the latter half (Patent Document 6), and a sweetness improving agent for sweet-containing foods and drinks containing phthalides as an active ingredient (Patent Document 7). ), The action of dihydroactinidiolide to improve the taste of food (Patent Document 8), and the taste enhancer of food and drink consisting of 3,4-dimethyl-5-propyridenfuran-2 (5H) -one (Patent Document 8). Patent Document 9) and the like have been proposed. However, in the above-mentioned proposals, since the lactone has strong flavor characteristics, the flavor of the lactone itself remains even when used at a low concentration, and the flavor is not always satisfactory.

On the other hand, for the ring-opened product of δ-lactone having 8 to 12 carbon atoms, a milk flavor-imparting agent using alkyl 5-acyloxydecanoate (Patent Document 10) and a milk flavor-imparting agent using ethyl 5-formyloxyalkanoate (Patent). Documents 11) and 5-[(1-alkoxy) ethoxy] alkyl alkanoates have been proposed (Patent Document 12), but δ-lactone ring-opened products having 14 to 18 carbon atoms are used for foods and drinks. No mention is made of improving flavors such as sweetness, acidity, saltiness, taste, richness, finish and texture.

Japanese Unexamined Patent Publication No. 2006-296356 Japanese Unexamined Patent Publication No. 2008-194015 Japanese Unexamined Patent Publication No. 2018-139558 Japanese Unexamined Patent Publication No. 2009-296951 Japanese Unexamined Patent Publication No. 2010-083894 WO2010 / 147222 Japanese Unexamined Patent Publication No. 2011-103774 Japanese Unexamined Patent Publication No. 2014-193146 Japanese Unexamined Patent Publication No. 2019-032044 Japanese Unexamined Patent Publication No. 2013-17378 Japanese Unexamined Patent Publication No. 2014-031331 Japanese Unexamined Patent Publication No. 2015-131773

An object of the present invention is to provide a flavor improving agent capable of improving the flavor of food and drink, a novel compound having the effect, and a method for producing the novel compound.

As a result of diligent studies by the present inventors, it has been found that acetoxy fatty acid ethyl ester, which is a lactone ring-opened product having a specific carbon number, is useful for improving the flavor of foods and drinks, and has led to the completion of the present invention.

That is, the present invention is as follows.
[1] General formula (1)

(R represents an alkyl group having 9 to 13 carbon atoms.)
A flavor improving agent containing one or more acetoxy fatty acid ethyl esters selected from the acetoxy fatty acid ethyl esters represented by.
[2] A food or drink to which the flavor improving agent according to [1] is added.
[3] The food or drink according to [2], which contains 1 ppb to 100 ppm of acetoxy fatty acid ethyl ester by adding the flavor improving agent according to [1].
[4] A method for improving the flavor of food and drink, which comprises adding the flavor improving agent according to [1].
[5] The method for improving flavor according to [4], wherein 1 ppb to 100 ppm of acetoxy fatty acid ethyl ester is added by adding the flavor improving agent according to [1].
[6] General formula (1)

(R represents an alkyl group having 10 to 13 carbon atoms.)
Acetoxy fatty acid ethyl ester represented by.
[7] General formula (2)

(R represents an alkyl group having 10 to 13 carbon atoms.)
By transesterification reaction with ethanol using an acid catalyst of δ-lactone represented by the general formula (3).

(R represents an alkyl group having 10 to 13 carbon atoms.)
The acetoxy fatty acid according to [6], which comprises the step of obtaining the hydroxy fatty acid ethyl represented by the above and the step of obtaining the acetoxy fatty acid ethyl ester according to [6] by acylating the hydroxy fatty acid ethyl with acetic anhydride. Method for producing ethyl ester.

The flavor improving agent containing acetoxy fatty acid ethyl ester having a specific carbon number of the present invention can improve the flavor of foods and drinks without adversely affecting the original flavor of foods and drinks. Further, according to the production method of the present invention, a novel acetoxy fatty acid ethyl ester having the effect can be easily produced.

The acetoxy fatty acid ethyl ester used as the active ingredient of the flavor enhancer of the present invention has the general formula (1).

(R represents an alkyl group having 9 to 13 carbon atoms.)
It is a compound represented by.

The method for synthesizing these acetoxy fatty acid ethyl esters is not limited, but can be synthesized by, for example, the following method.

First, the hydroxy fatty acid ethyl represented by the general formula (3) is obtained by a transesterification reaction with ethanol using an acid catalyst using the lactones represented by the general formula (2) as a substrate.

The lactones used in this reaction can be synthesized by a known method, or commercially available products can also be used.

The amount of ethanol used in this reaction is arbitrary as long as it is equal to or greater than the amount of the lactones that are the substrates, but since the transesterification reaction is a reversible reaction, the equilibrium is large so that it is biased toward the target product. It is preferable to use an excess amount, preferably 5 to 15 equivalents with respect to the lactones as a substrate.

The acid catalyst used in this reaction may be any acid catalyst that can be used for the transesterification reaction, and preferred examples thereof include sulfuric acid and p-toluenesulfonic acid monohydrate. The amount of the acid catalyst used is arbitrary as long as it is a catalytic amount, but is preferably 0.01 to 0.03 equivalent with respect to the lactones as the substrate.

The reaction temperature may be arbitrarily determined depending on the lactones used and the acid catalyst, but is preferably between 20 and 40 ° C. The reaction time may be determined while monitoring the progress of the reaction by thin layer chromatography, gas chromatography, or the like, but the reaction is preferably carried out for 3 to 4 hours.

Next, the acetoxy fatty acid ethyl ester of the present invention represented by the general formula (1) is obtained by acylating the hydroxy fatty acid ethyl represented by the general formula (3) obtained in the above reaction with acetic anhydride.

The hydroxy fatty acid ethyl used in this reaction can be used by purifying the crude product obtained in the above reaction, but it may be used as it is.

As the acylating agent used in this reaction, any carboxylic acid anhydride or carboxylic acid halide that can be used for acylation may be used, and acetic anhydride is a preferable example. The amount of the acylating agent used is arbitrary as long as it is equivalent to or more than the lactones as a substrate, but it is preferable to use an excess amount with respect to the hydroxy fatty acid ethyl, preferably in the range of 2 to 3 equivalents.

Pyridine can be used as a solvent in this reaction. The amount of pyridine used can be reduced, and in that case, in order to suppress the intermolecular reaction between the hydroxy fatty acid ethyls as the substrate, it is preferable to use a solvent inactive for the substrate and the acylating agent in combination, as a preferable example. Toluene can be mentioned.

The reaction temperature may be arbitrarily determined depending on the hydroxy fatty acid ethyl used and the acylating agent, but it is preferably carried out at room temperature. The reaction time may be determined by monitoring the progress of the reaction by thin layer chromatography, gas chromatography, or the like, but it is preferable to carry out the reaction overnight.

The acetoxy fatty acid ethyl ester of the present invention obtained as described above may be purified by means such as column chromatography and vacuum distillation, if necessary.

By adding the flavor improving agent of the present invention to a food or drink, the flavor of the food or drink can be improved without adversely affecting the original flavor of the food or drink. In the present invention, "improving the flavor of food and drink" means each element consisting of the basic tastes of sweetness, acidity, saltiness and umami of foods and drinks, and the peripheral sensations of basic tastes such as richness, afterglow and texture. It refers to improving one or more of the elements. In addition, "improvement" in the present invention includes any of enhancing, imparting and suppressing one or more of the above-mentioned elements as long as it is evaluated to be preferable in the sensory evaluation of food and drink. Is done.

The richness of food and drink in the present invention refers to the thickness felt from the content to the aftertaste, and is an element including a rich feeling and complexity, and the afterglow of food and drink is the lingering sound of food and drink from the entire mouth to the throat after swallowing. It refers to a flavor that lasts for a while toward the back. The texture of food and drink refers to the flavor that comprehensively expresses the main characteristics and characteristics of the food and drink.

The food or drink to which the flavor improving agent of the present invention is applied is not particularly limited, and examples of the food or drink include fruit beverages, beverages containing fruit juice, vegetable juices, effervescent beverages, concentrated juices, frozen juices, sports drinks, and nutrition. Drinks, other functional drinks, flavored teas, milk drinks, lactic acid bacteria drinks, soy milk and other beverages in general, yogurt, jelly, mousse, desserts, ice cream, lacto ice, ice milk, sherbet and other cold drinks, ice cream, cakes , Cookies, biscuits, pies, rice cakes, other rice cakes and other Western and Japanese sweets, including baked goods and steamed sweets, breads, snacks, chewing gum, hard candy, soft candy, jelly beans, gummy, locks General sugar confectionery including cream, fruit flavor sauce, jam and marmalade, sweetener, syrup, curry roux, stew roux, hayashi rice roux, hashed beef roux, sauce, seasoning sauce, powder seasoning, liquid seasoning, dressing, fried Seasonings such as flour, pasta sauce, gratin sauce, cooked rice base (paeria, biryani, pilaf, etc.), fried rice base, mabo tofu base, pot base, Chinese juice base, consomme soup base, etc. Instant noodles such as cup ramen, cup yakisoba, bag noodles, instant rice such as cup rice, retort foods, frozen foods (fried rice, pilaf, dumplings, grilled, fried, hamburger, fried, croquette, gratin, pizza, etc.), Cooked foods such as canned foods and processed foods can be mentioned, and oral hygiene products include pharmaceuticals such as oral refreshing agents, mouthwashes, toothpastes and other non-medicinal products, and syrups and the like, but are limited to these. Not done.

The acetoxy fatty acid ethyl ester used in the flavor improving agent of the present invention may be used alone or in combination of two or more.

The suitable amount of the flavor improving agent of the present invention added to the food or drink varies depending on the food or drink to be added, but the flavor of the acetoxy fatty acid ethyl ester itself does not adversely affect the original flavor of the food or drink, or the acetoxy fatty acid ethyl ester. It is preferable that 1 ppb to 100 ppm of acetoxy fatty acid ethyl ester, which is an active ingredient, is contained in the food or drink so that the flavor of the whole food or drink is not blurred due to excessive addition of the above, and 10 ppb to 10 ppm is contained in the food or drink. Is more preferable. In the present invention, ppt, ppb, ppm and% indicate mass ratios unless otherwise specified.

The flavor improving agent of the present invention may be added to foods and drinks as it is and used, or may be appropriately diluted with a solvent or the like for convenience in use. The solvent used for dilution is not particularly limited as long as it is commonly used in fragrance compositions. Further, it may be prepared as a fragrance composition in advance, and as long as it does not adversely affect the flavor, it may be a composition to which other additives or additives commonly used as ingredients other than fragrance are added. Further, in the present invention, a formulation technique generally applied to fragrances can be applied, and it can be prepared into a desired form depending on the situation such as powdering and encapsulation. Since the amount of the flavoring composition prepared as described above added to foods and drinks is generally about 1% at the maximum, the active ingredient in any form so as to obtain the flavor improving effect. It is preferable to prepare the acetoxy fatty acid ethyl ester so as to contain 100 ppb or more.

The flavor improving agent of the present invention may be added at any time in the manufacturing process as long as it can be evenly mixed in the food and drink.

[Example 1] Synthesis of ethyl 5-acetoxytetradecanoate Under a nitrogen atmosphere, δ-tetradecalactone (1.5 g, 6.6 mmol), ethanol (3.0 g), and p-toluenesulfonic acid monohydrate are placed in a test tube. A Japanese product (0.02 g, 0.11 mmol) was charged and stirred at 30 ° C. for 3 hours. Water (12 ml) was added, the mixture was extracted with toluene (10 mL), and the resulting toluene layer was washed twice with water (10 mL). By concentrating under reduced pressure, ethyl 5-hydroxytetradecanoate (1.8 g) was obtained as a colorless oily crude product.

Under a nitrogen atmosphere, the ethyl 5-hydroxytetradecanoate (1.8 g, 6.6 mmol), toluene (10.0 g), pyridine (0.2 g), acetic anhydride (2.0 g) obtained above were placed in a test tube. 19.6 mmol) was charged, and the mixture was stirred overnight at room temperature. Water (10 ml) was added, and the mixture was extracted with toluene (10 mL), and the obtained toluene layer was washed successively with 5% aqueous sodium hydrogen carbonate solution (10 mL) and water (10 mL × 2 times). The residue (1.9 g) obtained by concentration under reduced pressure was distilled and purified with a silica gel chromatogram to obtain ethyl 5-acetoxytetradecanoate (0.7 g, 2.2 mmol) as a colorless oil. .. The yield from δ-tetradecalactone was 33%.

[Example 2] Synthesis of ethyl 5-acetoxyhexadecanoate Under a nitrogen atmosphere, δ-hexadecalactone (5.0 g, 19.7 mmol), ethanol (9.1 g), sulfuric acid (0.06 g, 0) were placed in a test tube. .59 mmol) was charged and stirred at 20 ° C. for 6 hours. A 5% aqueous sodium hydrogen carbonate solution (11 mL) was added, the mixture was extracted with ethyl acetate (20 mL), and the obtained ethyl acetate layer was washed 3 times with 10% saline (11 mL). By concentrating under reduced pressure, ethyl 5-hydroxyhexadecanoate (5.9 g) was obtained as a colorless oily crude product.

Under a nitrogen atmosphere, the ethyl 5-hydroxyhexadecanoate (5.9 g, 19.6 mmol), toluene (12.0 g), pyridine (2.0 g), acetic anhydride (4.0 g) obtained above were placed in a test tube. 39.3 mmol) is charged and stirred overnight at room temperature. Water (15 mL) was added, and the mixture was extracted with toluene (10 mL), and the obtained toluene layer was washed successively with 5% aqueous sodium hydrogen carbonate solution (15 mL) and water (15 mL x 2 times). The residue (6.8 g) obtained by concentration under reduced pressure was distilled and purified with a silica gel chromatogram to obtain ethyl 5-acetoxyhexadecanoate (4.5 g, 13.1 mmol) as a colorless oil. .. The yield from δ-hexadecalactone was 66%.

The physical characteristics of the obtained ethyl 5-acetoxyhexadecanoate were as follows.
^{1 1} H-NMR (400 MHz, CDCl ₃ ): δppm 0.88 (t, 3H, J = 6.9 Hz), 1.24-1.32 (m, 21H), 1.52-1.69 (m, 6H), 2.04 (s, 3H) 2.30 (t, 2H, J = 7.6Hz), 4.12 (q, 2H, J = 7.2Hz), 4.87 (quin, 1H, J) = 6.1Hz)
¹³ C-NMR (400 MHz, CDCl ₃ ): δppm 14.06, 14.18, 20.64, 21.18, 22.63, 25.23, 29.29, 29.44, 29.47, 29. 51, 29.57, 29.58, 31.85, 33.31, 33.93, 33.95, 60.22, 73.72, 170.82, 173.32

[Example 3] Synthesis of ethyl 5-acetoxyoctadecanoate Under a nitrogen atmosphere, δ-octadecalactone (3.8 g, 13.4 mmol), ethanol (6.2 g), sulfuric acid (0.11 g, 1) were placed in a test tube. .09 mmol) was charged and stirred at 30 ° C. for 6 hours. A 5% aqueous sodium hydrogen carbonate solution (7 mL) was added, the mixture was extracted with ethyl acetate (10 mL), and the obtained ethyl acetate layer was washed 3 times with water (6 mL). By concentrating under reduced pressure, ethyl 5-hydroxyoctadecanoate (4.3 g) was obtained as a colorless oily crude product.

Under a nitrogen atmosphere, the ethyl 5-hydroxyoctadecanoate (4.3 g, 13.4 mmol), toluene (10.7 g), pyridine (2.0 g), acetic anhydride (2.8 g) obtained above were placed in a test tube. 27.4 mmol) was charged, and the mixture was stirred overnight at room temperature. Water (10 ml) was added, and the mixture was extracted with toluene (10 mL), and the obtained toluene layer was washed successively with 5% aqueous sodium hydrogen carbonate solution (10 mL) and water (10 mL × 2 times). The residue (3.4 g) obtained by concentration under reduced pressure was distilled and purified with a silica gel chromatogram to obtain ethyl 5-acetoxyhexadecanoate (1.0 g, 2.7 mmol) as a colorless oil. .. The yield from δ-octadecalactone was 21%.

The physical characteristics of the obtained ethyl 5-acetoxyoctadecanoate were as follows.
^{1 1} H-NMR (400 MHz, CDCl ₃ ): δppm 0.88 (t, 3H, J = 6.8 Hz), 1.24-1.27 (m, 25H), 1.52-1.69 (m, 6H), 2.04 (s, 3H) 2.30 (t, 2H, J = 7.4Hz), 4.13 (q, 2H, J = 7.2Hz), 4.88 (quin, 1H, J) = 6.1Hz)
¹³ C-NMR (400 MHz, CDCl ₃ ): δppm 14.06, 14.18, 20.64, 21.18, 22.64, 25.23, 29.31, 29.45, 29.47, 29. 52, 29.59, 29.63, 31.86, 33.31, 33.95, 60.22, 73.72, 170.82, 173.32

[Reference example]
Ethyl 5-acetoxytetradecanoate (hereinafter, may be referred to as compound 1), ethyl 5-acetoxyhexadecanoate (hereinafter, may be referred to as compound 2) and 5-acetoxy, which are the active ingredients of the flavor enhancer of the present invention. When the taste and aroma of the compound itself were evaluated for ethyl octadecanoate (hereinafter, may be referred to as compound 3), all the compounds exhibited a weak bitterness, and the aroma was as shown in Table 1. .. In the following examples, the concentration of the acetoxy fatty acid ethyl ester used was set to 100 ppm or less so that the taste and aroma of the compound itself would not be a problem and the flavor of the whole food and drink would not be blurred due to the excessive addition of the compound. ..

[Example 4] Evaluation of beverage containing peach juice to which the compound of the present invention is added A solution obtained by diluting the compound shown in Table 1 to 100 ppm with ethanol (hereinafter referred to as “compound solution”) is the peach juice shown in Table 2. 0.01% was added to the beverage base containing (the addition concentration of the compound in the food and drink was 0.01 ppm), and sensory evaluation was performed in comparison with the beverage base containing no additives. The evaluation was made on a 7-point scale as shown in Table 3, and was conducted by four trained in-house panels. The results are shown in Table 4. As a result of the sensory evaluation, the sweetness, richness and finish of all the compounds were improved, a peach-like fruit juice feeling was imparted, and the overall flavor was improved. No offensive taste or odor was observed.

[Example 5] Evaluation of a beverage containing orange juice to which the compound of the present invention was added 0.01% of the compound solution was added to the beverage base containing orange juice shown in Table 5 (the addition concentration of the compound in the food and drink was 0. 01 ppm), sensory evaluation was performed in comparison with the additive-free beverage base. The evaluation was performed according to the same criteria as in Example 4, and was performed by four trained in-house panels. The results are shown in Table 6. As a result of the sensory evaluation, the sweetness, richness and finish of all the compounds were improved, an orange-like fruit juice feeling was imparted, and the overall flavor was improved. No offensive taste or odor was observed.

[Example 6] Evaluation of commercially available lemon juice to which the compound of the present invention is added 0.01% of the compound solution is added to commercially available lemon juice (the addition concentration of the compound in food and drink is 0.01 ppm), and the juice is not added. A sensory evaluation was performed in comparison with. The evaluation was performed according to the same criteria as in Example 4, and was performed by two trained in-house panels. The results are shown in Table 7. As a result of the sensory evaluation, the sweetness, acidity, richness and finish were improved for all the compounds, and a lemon-like fruit juice feeling was imparted, and the overall flavor was improved. No offensive taste or odor was observed.

[Example 7] Evaluation of coffee beverage to which the compound of the present invention is added 0.01% of the compound solution is added to a coffee beverage base in which 5% of sugar is added to commercially available sugar-free black coffee (addition of a compound in food and drink). The concentration was 0.01 ppm), and sensory evaluation was performed in comparison with the additive-free coffee beverage base. The evaluation was performed according to the same criteria as in Example 4, and was performed by 6 trained in-house panels. The results are shown in Table 8. As a result of the sensory evaluation, one or more of the sweetness, richness and lingering taste were improved for each compound, and for compound 1 and compound 3, freshly roasted coffee and freshly ground coffee were obtained. It also gives a coffee feeling reminiscent of freshly brewed coffee, and the overall flavor is improved. No offensive taste or odor was observed.

[Example 8] Evaluation of cookie to which the compound of the present invention is added 0.1% of the butter flavor shown in Table 9 to which 1% of the compound shown in Table 1 is added is added to the cookie dough shown in Table 10 (food and drink). The added concentration of the compound in the product is 10 ppm), and this cookie dough was placed in an oven preheated to 150 ° C at the bottom and 180 ° C at the top and baked for 7 minutes to prepare a cookie, which was compared with the cookie without butter flavor. A sensory evaluation was performed. The evaluation was performed according to the same criteria as in Example 4, and was performed by four trained in-house panels. The results are shown in Table 11. As a result of the sensory evaluation, the sweetness, richness and finish of each compound were improved, a rich buttery feeling was imparted, and the overall flavor was improved. No offensive taste or odor was observed.

[Example 9] Evaluation of monosodium glutamate-containing saline solution to which the compound of the present invention was added 0.01% of the compound solution was added to the monosodium glutamate-containing saline solution shown in Table 12 (the addition concentration of the compound in food and drink was 0). 0.01 ppm), sensory evaluation was performed in comparison with the additive-free one. The evaluation was performed according to the same criteria as in Example 4, and was performed by three trained in-house panels. The results are shown in Table 13. As a result of the sensory evaluation, one or more of the salty taste, the umami, the richness and the afterglow were improved for each compound. No offensive taste or odor was observed.

[Example 10] Evaluation of commercially available noodle soup containing the compound of the present invention 0.01% of the compound solution was added to the commercially available noodle soup (the concentration of the compound added in the food and drink was 0.01 ppm), and compared with the additive-free noodle soup. The sensory evaluation was performed. The evaluation was performed according to the same criteria as in Example 4, and was performed by three trained in-house panels. The results are shown in Table 14. As a result of the sensory evaluation, the salty taste, umami, richness and aftertaste were improved for all the compounds, and for the compound 2 and the compound 3, the soy sauce's first taste and the Japanese-style soup stock's mellow flavor (soup sensation) were enhanced. No offensive taste or odor was observed.

[Example 11] Evaluation of a commercially available curry to which the compound of the present invention is added 0.01% of a compound solution is added to a curry prepared using a commercially available curry (the addition concentration of the compound in food and drink is 0.01 ppm). A sensory evaluation was performed in comparison with the additive-free curry. The evaluation was performed according to the same criteria as in Example 4, and was performed by one trained in-house panel. The results are shown in Table 15. As a result of the sensory evaluation, the richness and finish of all the compounds were improved, and the well-cooked sweet flavor (curry feeling) peculiar to cooked foods was also enhanced. Further, with respect to compound 1, a spicy feeling reminiscent of the pungent flavor of spices was also imparted. No offensive taste or odor was observed.

Claims (7)

General formula (1)

(R represents an alkyl group having 9 to 13 carbon atoms.)
A flavor improving agent for foods and drinks containing one or more acetoxy fatty acid ethyl esters selected from the acetoxy fatty acid ethyl esters represented by. A food or drink to which the flavor improving agent according to claim 1 is added. The food or drink according to claim 2, which contains 1 ppb to 100 ppm of acetoxy fatty acid ethyl ester by adding the flavor improving agent according to claim 1. A method for improving the flavor of food and drink, which comprises adding the flavor improving agent according to claim 1. The method for improving flavor according to claim 4, wherein 1 ppb to 100 ppm of acetoxy fatty acid ethyl ester is added by adding the flavor improving agent according to claim 1. General formula (1)

(R represents an alkyl group having 10 to 13 carbon atoms.)
Acetoxy fatty acid ethyl ester represented by. General formula (2)

(R represents an alkyl group having 10 to 13 carbon atoms.)
By transesterification reaction with ethanol using an acid catalyst of δ-lactone represented by the general formula (3).

(R represents an alkyl group having 10 to 13 carbon atoms.)
The acetoxy fatty acid according to claim 6, which comprises a step of obtaining the hydroxy fatty acid ethyl represented by the above and a step of obtaining the acetoxy fatty acid ethyl ester according to claim 6 by acylating the hydroxy fatty acid ethyl with anhydrous acetic acid. Method for producing ethyl ester.