JP4646753B2 - Flavor improver - Google Patents

Description

  The present invention is improved by containing a flavor improving agent containing (S) -2-methylbutanethioate S-alkyl which improves the quality and smell of flavors of foods and drinks, and this optically active substance. The present invention relates to foods and drinks having a flavor.

  Conventionally, many of the flavor improving agents used in food additives and the like use racemates, and there are few examples of using optically active compounds in food additives and the like. For example, racemic 2-methylbutanethioate S-alkyl is known to exist in natural products, particularly in fruits and beer (Non-patent Documents 1 to 13). Among these racemic 2-methylbutanethioate S-alkyls, in particular, S-methyl 2-methylbutanethioate is a food fragrance for the purpose of giving a fermented odor of food and a sense of ripeness of fruits. It is used as.

  However, foods and drinks containing these conventional food fragrances are satisfied for the time being with an excellent fermented odor and a sense of ripeness of fruits, but they are still not sufficient. There is also plenty of room for improvement in terms of giving a smell.

  On the other hand, in relation to the analysis of cheese aroma components, S-methyl (S) -2-methylbutanethioate and racemic S-methyl 2-methylbutanethioate were analyzed by gas chromatography, There has been a report on aroma as a compound (Non-Patent Document 14). Further, in the analysis of hop aroma components, aroma as a racemic compound of S-methyl 2-methylbutanethioate has been reported (Non-patent Document 8).

  According to these documents, the aroma of racemic 2-methylbutanethioate S-methyl is wild strawberry (Non-patent document 14) or Cooked vegetable, Sulphury, Soapy / fatty (Non-patent document 8). (S) -2-Methylbutanethioate S-methyl aroma is described as rubbery (Non-Patent Document 14). In addition, the fragrance of (R) -2-methylbutanethioate S-methyl has not been reported.

  However, all of these reports have only evaluated the aroma of a single compound that is not directly related to the flavor of the food and drink, and (S) -2-methylbutanethioic acid S-alkyl was consumed. It is not actually evaluated for flavor and smell.

Food Chemistry (2000), 69 (3), 319-330 Journal of the Institute of Brewing (1983), 89 (2), 87-91 Proceedings of the Congress-European Brewery Convention (1981), 18th, 161-8 Proceedings of the Congress-European Brewery Convention (1979), 17th, 79-89 Proceedings of the Congress-European Brewery Convention (1981), 17th, 91-104 Technical Quarterly-Master Brewers Association of the Americas (1981), 18 (1), 26-30 Organic Magnetic Resonance (1979), 12 (10), 557-60 Proceedings of the Analytical Division of the Chemical Society (1976), 13 (7), 215-17 Journal of Organic Chemistry (1973), 38 (24), 4239-43 Flavor and Fragrance Journal (1996), 11 (5), 295-303 Tetrahedron Letters (1971), (30), 2837-8 Development in Food Science (1988), 18 (Flavors Fragrances), 573-85 32nd Annual Meeting on Fragrances, Terpenes and Essential Oil Chemistry, 31-33, (October 24, 1988) Lebensmittel-Wissenschaft und-Technologie (1979), 12 (5), 258-61

  The present inventors have proposed a specific flavoring agent that can solve the problem of beverage flavor and beverage smelling that has been difficult to improve in the past, that is, a flavor improving agent for beverages and a beverage using the same. When the S-alkyl (S) -2-methylbutanethioate having the prescribed optical purity was added to the beverage, the flavor of the racemic product was lacking, and there was a slight sensation. Unlike the ones that are used, the fruity note has a slightly blue color, and it has a very clear and diffusive scent that leads to the ripeness of the fruit. As a result, it was discovered that the scent was remarkably superior. That is, when (S) -2-methylbutanethioate S-alkyl having a predetermined optical purity is added to a beverage, a very clear and diffusive fragrance that leads to a full ripeness of the fruit stands out. It was found that the beverage was remarkably excellent in terms of flavor and smell, such as enhanced flavor.

  And based on these findings, the present inventors have further studied the food to widen the scope of application, and have completed the present invention, that is, the subject of the present invention is a sense of ripeness of fruits. It is to provide a novel flavor improving agent that gives a very clear aroma and a remarkable scent leading to the above, and a food and drink having an improved flavor.

  That is, the present invention intends to solve the above problems by the following (1) to (4).

(1) S-alkyl (S) -2-methylbutanethioate has an optical purity of 70% e.e. e. The flavor improving agent characterized by being contained above.

(2) The flavor improving agent according to (1), wherein the S-alkyl (S) -2-methylbutanethioate is S-methyl (S) -2-methylbutanethioate.

(3) Optical purity is 70% e.e. e. The above S-alkyl (S) -2-methylbutanethioate has an improved flavor characterized in that it is contained at a ratio of 10 ⁻⁸ to 10 ⁵ ppb in terms of an optical purity of 100%. Food and drink.

(4) The food and drink having an improved flavor according to (3), wherein the S-alkyl (S) -2-methylbutanethioate is S-methyl (S) -2-methylbutanethioate.

  The flavor improver containing (S) -2-methylbutanethioic acid S-alkyl of the present invention is very useful for adding to various drinks such as fruit juices and foods, leading to a sense of fruit ripeness. It has a clear and diffusive fragrance, and the flavor and flavor of the flavor formulation can be enhanced, so that it can provide foods and drinks that are remarkably excellent in terms of flavor and smell. The product value of can be significantly increased.

  The present invention is described in detail below.

  In the flavor improving agent of the present invention, S-alkyl (S) -2-methylbutanethioate is used as an essential component. Specific examples of the S-alkyl (S) -2-methylbutanethioate include S-methyl ester, S-ethyl ester, and Sn-propyl ester of (S) -2-methylbutanethioic acid. , S-isopropyl ester, S-butyl ester, S-2-methylpropyl ester, S-pentyl ester, S-2-methylbutyl ester, S-3-methylbutyl ester, S-hexyl ester, S-cis-3 -Hexenyl ester, S-heptyl ester, S-octyl ester, etc. can be mentioned.

  The (S) -2-methylbutanethioic acid S-alkyl may be used as one essential component or as a mixture of two or more thereof. Among these compounds, the flavor improving agent of the present invention may be used. A preferred compound as an essential component is S-methyl (S) -2-methylbutanethioate.

  As the S-alkyl (S) -2-methylbutanethioate used in the present invention, one obtained by extraction from a natural product can be used, or one obtained by a chemical synthesis method is used. However, when a large amount of S-alkyl (S) -2-methylbutanethioate is used, it is preferable to select one obtained by a chemical synthesis method.

  Examples of the chemical synthesis method of S-alkyl (S) -2-methylbutanethioate include a method of reacting (S) -2-methylbutanoic acid as a raw material with an acid halide and then reacting with alkylthiol. it can.

  Further, as a chemical synthesis method of (S) -2-methylbutanoic acid, the method described in JP-A-63-239245, that is, tiglic acid ((E)-) for which a commercially available product can be easily obtained. Examples thereof include a method of asymmetric hydrogenation using 2-methyl-2-butenoic acid) as a raw material and using a ruthenium-optically active phosphine complex having a specific absolute configuration as a catalyst.

The chemical synthesis method of (S) -2-methylbutanoic acid will be described in more detail. An autoclave in which tiglic acid is dissolved in a solvent such as methanol and ethanol and substituted with an inert gas is charged with ruthenium-optical activity. Since the phosphine complex is added to 1/100 to 1/1000 times the mole of tiglic acid, hydrogenation is carried out by stirring for 1 to 100 hours at a hydrogen pressure of 4 to 125 kg / cm ² and a reaction temperature of 5 to 50 ° C. is there.

  Further, as a hydrogen source, a method described in JP-A-3-157346 which does not use hydrogen gas can be used. However, according to this method, a primary or secondary alcohol is used as a hydrogen donor in a large excess. Will be used. After the reaction, if the solvent is distilled off and the residue is distilled under reduced pressure, the desired (S) -2-methylbutanoic acid can be obtained.

Examples of ruthenium-optically active phosphine complexes that can be used include the following.
Ru _x H _y Cl _z [(−) − (R−BINAP)] ₂ (S) _p (1)
{Wherein (-)-(R-BINAP) is (-)-2,2'-bis (diphenylphosphino) -1,1'-binaphthyl or (-)-2,2'-bis (di -P-methylphenylphosphino) -1,1'-binaphthyl and the like, and S represents a tertiary amine. y represents 0 or 1; when y is 0, x is 2, Z is 4, p is 1, and when y is 1, x is 1, Z is 1, and p is 0. }

{Ru [(−)-(X-BINAP)] _q } (OCOR ¹ ) (OCOR ² ) (2)
{In the formula, (-)-(X-BINAP) represents that an amino group, an acetylamino group or a sulfone group may be substituted at the 5-position and 5'-position of two naphthyl groups, (-)-2,2'-bis (diphenylphosphino) -1,1'-binaphthyl optionally substituted with a lower alkyl group at the p-position is shown. R ¹ and R ² represent a lower alkyl group, a halogeno lower alkyl group, a phenyl group which may be substituted by a lower alkyl group, an α-aminoalkyl group or an α-aminophenylalkyl group, or R ¹ and R 2 ² may combine to form an alkylene group. q represents 1 or 2. }

{RuH _l [(−) − (R-BINAP)] _v } Y _w (3)
{Wherein (-)-(R-BINAP) represents the same content as described above. Y represents ClO ₄ , BF ₄ or PF ₆ . l represents 0 or 1; when l is 0, v represents 1, w represents 2, and when l is 1, v represents 2, and w represents 1. }

{Ru [(−) − (BIPHEMP)]} Y ₂ (4)
{Wherein (-)-(BIPHEMP) is (-)-2,2'-dimethyl-6,6'-bis (diphenylphosphino) -1,1'-biphenyl, (-)-2,2 '-Dimethyl-6,6'-bis (di-p-methylphenylphosphino) -1,1'-biphenyl or (-)-2,2'-dimethyl-6,6'-bis (di- p-methoxyphenylphosphino) -1,1'-biphenyl and the like. Y indicates the same content as described above. )

  Any of the ruthenium-optically active phosphine complexes (1) to (3) described above can be obtained by the method described in JP-A-63-239245. The ruthenium-optically active phosphine complex (4) is a complex described in JP-A No. 63-145292.

  In the flavor improving agent of the present invention, the S-alkyl (S) -2-methylbutanethioate obtained as described above has an optical purity of 70% e.e. e. It is necessary to contain above.

  S-alkyl (S) -2-methylbutanethioate synthesized according to the method described in JP-A-63-239245 has an optical purity of 75% e.e. e. Although it was obtained with a high degree of purity, it was tested to what degree of optical purity the effect of the (S) form is manifested. e. It was found that the effect of the (S) body began to appear with a degree of optical purity. Therefore, it has been found that if it is higher than these optical purities, the flavor and scent effect of food and drink can be reliably expected by using it as it is as an essential component of the flavor improving agent of the present invention without purification.

  Here, “scenting” not only means that the flavor of food and drink spreads in the mouth instantaneously, but also means that the scent is felt only by the presence of food and drink near the mouth.

  The optical purity is 70% e.e. e. In order to obtain the above S-alkyl (S) -2-methylbutanethioate, a high optical purity (S) -2-methylbutanethioate S-alkyl obtained by the above-described chemical synthesis method, and natural products In particular, racemic 2-methylbutanethioate S-alkyl, which is known to be widely present in fruits, beer and the like, can also be appropriately mixed.

  As these racemic 2-methylbutanethioate S-alkyl, for example, S-methyl 2-methylbutanethioate is beer, hop, cheese, etc., S-ethyl 2-methylbutanethioate is durian, etc. It is known that S-butyl 2-methylbutanethioate is contained in carbnam and the like. In addition, Sn-propyl ester, S-isopropyl ester, S-butyl ester, S-2-methylpropyl ester, S-pentyl ester, S-2-methylbutyl ester, S of 2-methylbutanethioic acid, S It is known that -3-methylbutyl ester, S-hexyl ester, S-cis-3-hexenyl ester, S-heptyl ester, S-octyl ester and the like are contained in various fruits and the like.

  The flavor improving agent of the present invention has an optical purity of 70% e. e. The above-mentioned (S) -2-methylbutanethioic acid S-alkyl is contained in a mixture of one or more thereof, and other ingredients such as fragrances are blended and added to food and drink It is what is done. Other ingredients such as fragrances blended in the flavor improver can be used without particular limitation as long as they are components used in ordinary food fragrances. Further, the content of S-alkyl (S) -2-methylbutanethioate in the flavor improving agent of the present invention is not particularly limited, but it may be contained in the flavor improving agent at a ratio of about 1 to 15% by weight. preferable.

In addition, the food and drink having an improved flavor according to the present invention has an optical purity of 70% e.e. e. The above-mentioned (S) -2-methylbutanethioic acid S-alkyl is contained in a mixture of one or two or more thereof, and the flavor improvement of the present invention is formed by blending other components such as a fragrance. It contains an agent and has improved flavor and smell. Although the addition amount to the various foods and drinks of the flavor improving agent of this invention can be suitably changed with the kind of foods and drinks to add, it is about (S) -2-methylbutanethioic acid S-alkyl with respect to foods and drinks. 10 ⁻⁸ to 10 ⁵ ppb (converted to an optical purity of 100%) is preferable. When the addition amount is less than about 10 ⁻⁸ ppb, the effect of addition is not clearly observed, and about 10 ⁵ ppb is reduced. If the amount is too large, the flavor of the food and drink itself may be impaired.

  In particular, when added to a beverage, the addition amount may be about 1 to 100 ppm as S-alkyl (S) -2-methylbutanethioate with respect to the beverage.

  The food and drink for adding the flavor improving agent of the present invention is not particularly limited as long as it is a variety of foods and drinks that are expected to have a flavor improving effect. Examples of food include caramel, candy, chocolate, chewing gum, and grilled food. Confectionery such as confectionery, frozen confectionery such as ice cream and sorbet, pudding, jelly, etc., and as beverages, carbonated beverages such as cider, lemon lime, various fruit sodas, guarana, cola beverages, Examples include various fruit juice drinks containing no fruit juice or natural fruit juice, nectar, concentrated syrup for dilution, milk drink, taste drink, functional drink, liquor and the like.

  The flavors when the flavor improving agent of the present invention and these racemates conventionally used as food flavors were added to beverages were compared as follows.

(1) Selection of panelists A total of 10 professional flavourists (Flavorists, who create food flavors) in their 20s and 30s were selected, including 8 men and 2 women.

(2) Preparation of Beverage Flavor Improvement Agent by Recombination Formulation A beverage flavor improvement agent was prepared by recombination of racemic 2-methylbutanethioate S-alkyl in an existing flavor prescription into (S) form.

(3) Addition to beverage A predetermined amount of the flavor prepared in (2) was added to the model beverage, and the flavors when the (S) body or racemic body was added were compared.

  In addition, the expression of the odor in an Example and a comparative example is referring to the expression described in Motoichi Into, "Actual knowledge of fragrance | flavor" (March 25, 1975), Toyo Keizai Shinposha, page 3. did. Moreover, the unit of the prescription shown in the table | surface in an Example and a comparative example is represented by the weight part.

The analysis in this example was performed using the following analytical equipment.
Optical rotation;
Device: DIP-370 (manufactured by JASCO Corporation)
Proton nuclear magnetic resonance spectrum ( ¹ H-NMR);
Equipment: AM-400 type (400MHz) (Brucker)
Internal standard: Tetramethylsilane Infrared absorption spectrum (IR);
Equipment: Nicolet Avatar 360 FT-IR (manufactured by Nicolet Japan)
Mass spectrum (MS);
Instrument: M-80B mass spectrometer (ionization voltage: 20 eV) (manufactured by Hitachi, Ltd.)
Gas chromatograph instrument: HP-5890 (manufactured by Hewlett-Packard Company)
Column: PEG BC-WAX (0.25 mm × 50 m) (manufactured by GL Sciences Inc.)

Synthesis example 1
Production of (S) -2-methylbutanoic acid 0.2 g (2 mmol) of tiglic acid and 20 ml of methanol were placed in a 100 ml stainless steel autoclave previously purged with nitrogen, followed by Ru [(−)-BINAP] (BF ₄ ). ₂ {(−)-BINAP represents (−)-2,2′-bis (diphenylphosphino) -1,1′-binaphthyl. } 6.0 mg (0.007 mmol) was added, hydrogenation was carried out by stirring for 12 hours at a hydrogen pressure of 4 kg / cm ² and a reaction temperature of 20 ° C., and the solvent was distilled off to obtain the target (S) -2- 0.2 g (yield 100%) of methylbutanoic acid was obtained. The optical rotation was [α] _D ²⁵ = + 16.7 ° (neat), and the purity by gas chromatography was 100%. This was reacted with (R) -1-phenylethylamine to synthesize an amide and analyzed by gas chromatography. As a result, the optical purity of (S)-(+)-2-methylbutanoic acid was 88% e.e. e. Met.

Synthesis example 2
Production of (S) -2-methylbutanoic acid chloride (S) -2-methylbutanoic acid {[α] _D ²⁵ = + 16.7 ° (neat)} obtained in Synthesis Example 1 was added to 35.8 g (350 mmol). 50.0 g (420 mmol) of thionyl chloride was added dropwise at 50 ° C. over 3 hours, and then reacted at 80 ° C. for 1 hour. Excess thionyl chloride was distilled off under reduced pressure, and the residue was distilled under reduced pressure to obtain 40.4 g (yield 96%) of (S) -2-methylbutanoic acid chloride.
Boiling point: 35 ° C / 0.1 torr
¹ H-NMR (CDCl ₃ ): 0.98 (t, J = 7.5 Hz, 3H), 1.29 (d, J = 6.9 Hz, 3H), 1.58 to 1.66 (m, 1H) ), 1.79-1.87 (m, 1H), 2.78-2.85 (m, 1H)
¹³ C-NMR: 11.46 (CH ₃ ), 16.88 (CH ₃ ), 26.91 (CH ₂ ), 53.29 (CH), 178.05 (CO)

Synthesis example 3
(S) -2-Methylbutanethioate Production of S-methyl (S) -2-methylbutane obtained in Synthesis Example 2 under stirring in a mixture of 75 g of a 15% methyl mercaptan aqueous solution cooled to 0 ° C. and 100 mL of diethyl ether 16.1 g (120 mmol) of acid chloride was added dropwise over 1 hour. The organic layer was separated, washed with brine, diethyl ether was distilled off, and the residue was concentrated under reduced pressure to give 15.1 g of S-methyl (S) -2-methylbutanethioate (yield 86%). ) As a result of analysis by gas chromatography, the chemical purity was 100% and the optical purity was 88% e.e. e. Met.
Boiling point 32 ° C./5 torr.
[Α] _D ²⁰ = + 36.7 ° (neat)
¹ H-NMR (CDCl ₃ ): 0.92 (t, J = 7.5 Hz, 3H), 1.29 (d, J = 6.9 Hz, 3H), 1.43 to 1.52 (m, 1H) ), 1.70 to 1.78 (m, 1H), 2.28 (s, 3H), 2.54 to 2.60 (m, 1H)
¹³ C-NMR: 11.29 (CH ₃ ), 11.58 (CH ₃ ), 17.21 (CH ₃ ), 27.17 (CH ₂ ), 50.04 (CH), 204.22 (CO)

Example 1 and Comparative Example 1
Evaluation of aroma quality For S-methyl (S) -2-methylbutanethioate obtained in the synthesis example, sensory evaluation was performed by a perfume who had more than 5 years experience using the one attached to the bottle mouth and filter paper. It was. The evaluation results are shown in Table 1.

  As described above, S-methyl (S) -2-methylbutanethioate used in the flavor improving agent of the present invention is reminiscent of a fruity note with a slight bluishness and is very clear that leads to a full ripeness of the fruit. It had a fragrance rich in diffusibility. On the other hand, although the racemic body is a natural fragrance, it lacked strength and had a slight miscellaneous feeling.

Example 2 and Comparative Example 2
Based on the strawberry flavor formulation in Table 2, a flavor improver for beverages was prepared. Example 2 containing S-methyl (S) -2-methylbutanethioate obtained in Synthesis Example and Comparative Example 2 containing S-methyl racemic 2-methylbutanethioate It was. Each obtained flavor improving agent for beverages was added at a ratio of 0.1% by weight to a fruitless carbonated beverage containing 10% by weight of glucose and 0.1% by weight of citric acid. Table 3 shows the results of the evaluation of the flavor of each beverage by the above-mentioned 10 flavorists.

  As shown in Table 3, the beverage added with the flavor improver for beverage of Example 2 containing S-methyl (S) -2-methylbutanethioate is very clear and diffusible, which leads to a sense of ripeness of the fruit. In contrast to the rich scent, the addition of the flavor improving agent for beverages of Comparative Example 2 containing a racemic body, the freshness when S-methyl (S) -2-methylbutanethioate is added is I couldn't feel it at all.

Example 3
S-methyl (S) -2-methylbutanethioate synthesized according to the method described in JP-A-63-239245 has an optical purity of 88% e.e. e. Although it was obtained with a high degree of purity, it was confirmed that the optical purity of the (S) isomer was manifested with certain optical purity. (S) -2-methylbutanethioate S-methyl having an arbitrary optical purity is prepared by mixing the racemic compound in an arbitrary ratio, and the optical purity that allows the effect of the (S) isomer to be clearly and reliably discriminated. 2: Two-point identification method {To identify two samples A and B, first present samples A and B to the panel as bright samples and memorize their characteristics. Present as a blind sample, point out the sample that is different from A, and determine whether there is a difference between the two samples from the number of correct answers obtained in several iterations; Shin Sato “Introduction to Sensory Testing” 54 pages (October 16, 1978, published by Nikka Girensha Publishing Co., Ltd.)} were used for measurement.

  As a result, when S-methyl (S) -2-methylbutanethioate was used, the optical purity was 70% e.e. e. If it was above, it turned out that it can be used as it is, without refine | purifying, and the flavor improvement effect of food and drink can be anticipated reliably.

Claims (4)

(S) -2-Methylbutanethioate S-alkyl has an optical purity of 70% e.e. e. The flavor improving agent characterized by being contained above. The flavor improving agent according to claim 1, wherein the S-alkyl (S) -2-methylbutanethioate is S-methyl (S) -2-methylbutanethioate. Optical purity is 70% e.e. e. The above S-alkyl (S) -2-methylbutanethioate has an improved flavor characterized in that it is contained at a ratio of 10 ⁻⁸ to 10 ⁵ ppb in terms of an optical purity of 100%. Food and drink. The food and drink having an improved flavor according to claim 3, wherein the S-alkyl (S) -2-methylbutanethioate is S-methyl (S) -2-methylbutanethioate.