Flavor enhancer and flavor enhancing method for allium vegetables

Abstract

To develop a method for enhancing the flavor of Allium vegetables, and particularly, a method for enhancing, particularly when producing foods of Allium vegetables, the flavor of the produced Allium vegetables.SOLUTION: A flavor enhancer for Allium vegetables (excluding dried products) contains, as an active ingredient, a methoxypyrazine represented by the general formula in the figure. [In the formula, R1 represents a C2 to C4 alkyl group, and R2 represents hydrogen or a methyl group.]SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a flavor enhancer for Allium vegetables and a method for improving the flavor of Allium vegetables. In particular, the flavor of Allium vegetables can be improved by using the agent for improving the flavor of Allium vegetables when producing dried Allium vegetables. [Background technology]

[0002] Allium vegetables, such as dried green onions, dried chives, dried garlic, and dried onions, have traditionally been used as ingredients in instant foods such as instant miso soup and instant noodles, as well as many other foods. Methods for drying these Allium vegetables include hot air drying, freeze drying, vacuum drying, and microwave drying. Dried Allium vegetables have improved shelf life due to the reduction of moisture in the Allium vegetables, and are an ingredient that is expected to continue to be widely used in the future.

[0003] On the other hand, it has been pointed out that, regardless of the type of dried vegetable, the flavor may volatilize or a special flavor such as a metallic odor may be exhibited due to oxidation reactions of the cell tissue during the drying process. In this respect, it has been pointed out that dried vegetables have a flavor inferior to that of fresh vegetables. Furthermore, such problems also occur in dried Allium vegetables, and a method for avoiding this problem has been desired. On the other hand, as a method for dealing with such flavor deterioration of dried vegetables, for example, the following prior art has been disclosed. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2009-142244 [Patent Document 2] Patent Publication No. 7-298849

[0005] The techniques of Patent Documents 1 and 2 are excellent techniques for avoiding dry odor. However, Patent Document 1 is targeted at soups, and its range of application is limited. Furthermore, it requires the addition of monoglucosyl hesperidin, and the cost of this substance must also be taken into consideration. Furthermore, Patent Document 2 assumes that vegetables are crushed, and it has been pointed out that its applications are limited.

[0006] Furthermore, these methods are applicable to a wide range of vegetables that can be freeze-dried, and are not freeze-drying methods that are targeted at specific vegetables. However, vegetables vary in composition and characteristics depending on the type, and therefore, when producing dried vegetables, specific problems may arise depending on the type of vegetable. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present inventors have investigated a method for improving the flavor of Allium vegetables, taking Allium vegetables as the target vegetable, and have also investigated a method for improving the flavor of dried Allium vegetables, particularly in order to address the problem of flavor deterioration when producing dried foods of Allium vegetables. [Means for solving the problem]

[0008] The present inventors have repeatedly conducted experiments on the aroma components of various materials, and as a result of their intensive research, have discovered that the use of methoxypyrazine represented by general formula 1 has the effect of improving the flavor of Allium vegetables, leading to the completion of the present invention. That is, the first invention of the present application is a flavor improver for Allium vegetables, which contains as an active ingredient a methoxypyrazine represented by the following general formula 1:

[0009] [ka] [wherein R1 represents a C2-C4 alkyl group, and R2 represents hydrogen or a methyl group].

[0010] Next, in the present invention, it is preferable to use the flavor enhancer for dried Allium vegetables among vegetables of the genus Allium. That is, the second invention of the present application is "the flavor enhancer for Allium vegetables according to claim 1, which is a flavor enhancer for dried Allium vegetables."

[0011] Next, the present invention is directed to a method for producing vegetables of the genus Allium, which comprises a step of adding methoxypyrazine represented by the above general formula 1. That is, the third invention of the present application is a method for producing dried Allium vegetables, which includes a step of adding methoxypyrazine represented by the following general formula 1:

[0012] [ka] [wherein R1 represents a C2-C4 alkyl group, and R2 represents hydrogen or a methyl group].

[0013] Next, the present invention also contemplates the Allium vegetables themselves to which the methoxypyrazine represented by general formula 1 has been added. That is, the fourth invention of the present application is "a vegetable of the genus Allium to which methoxypyrazine represented by the following general formula 1 has been added.

[0014] [ka] [wherein R1 represents a C2-C4 alkyl group, and R2 represents hydrogen or a methyl group].

[0015] Next, in the fourth aspect of the present invention, the Allium vegetables are preferably dried Allium vegetables. That is, the fifth invention of the present application is "the Allium vegetable according to claim 4, wherein the Allium vegetable is a dried product."

[0016] Next, the present invention also contemplates a method for improving the flavor of Allium vegetables by utilizing methoxypyrazine represented by general formula 1. That is, the sixth invention of the present application is "a method for improving the flavor of Allium vegetables, characterized by utilizing methoxypyrazine represented by the following general formula 1.

[0017] [ka] [wherein R1 represents a C2-C4 alkyl group, and R2 represents hydrogen or a methyl group].

[0018] Next, in the seventh invention of the present application, the Allium vegetables are preferably dried Allium vegetables. That is, the seventh invention of the present application is "a method for improving the flavor of Allium vegetables according to claim 6, wherein the Allium vegetables are dried." [Effects of the Invention]

[0019] By using the flavor enhancer for Allium vegetables or the method for improving the flavor of Allium vegetables of the present invention, it is possible to improve the flavor of Allium vegetables, particularly dried Allium vegetables. [Brief explanation of the drawings]

[0020] [Figure 1] Front view of leek, a common Allium vegetable [Explanation of symbols]

[0021] 1 Leaf blade 2 Leaf sheath 3 Root DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be described in detail below based on the embodiments, but the present invention is not limited to these embodiments.

[0023] ─Methoxypyrazine─ The flavor enhancer for Allium vegetables of the present invention is a methoxypyrazine, particularly a compound represented by the following general formula 1 and substituents R1 and R2. Methoxypyrazine refers to a class of substances in which a methoxy group is bonded to a pyrazine ring.

[0024] [ka] [wherein R1 represents a C2-C4 alkyl group, and R2 represents hydrogen or a methyl group]

[0025] Here, R1 represents a C2-C4 alkyl group, and specific examples of this alkyl include ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, and tert-butyl groups, and R2 represents hydrogen or a methyl group.

[0026] The methoxypyrazines used in the present invention are commercially available, and certain of them can be used as food flavoring compounds. Food flavoring compounds are designated in Appendix 1 of the Enforcement Regulations of the Food Sanitation Act as food additives used for flavoring purposes.

[0027] Specifically, 2-ethyl-3-methoxypyrazine (CAS number: 25680-58-4), 2-isopropyl-3-methoxypyrazine (CAS number: 25773-40-4), 2-isobutyl-3-methoxypyrazine (CAS number: 24683-00-9), 2-sec-butyl-3-methoxypyrazine (CAS number: 24168-70-5), etc. are included in the specific items that have been determined to fall under the 18 categories of fragrances (so-called category 18) designated as designated additives or derivatives.

[0028] The methoxypyrazine used in the present invention can be purchased commercially, or synthesized.Furthermore, aromatic components extracted from foods, etc. by extraction (distillation, etc.) can also be used. In addition, when the methoxypyrazine of the present invention is used in the production of food, it is preferable to use a type in which it is dissolved in a solvent such as liquid oil or fat, or in water, ethanol, etc., or a type in which it is powdered together with various excipients, etc., as necessary.

[0029] A specific method of addition includes spraying liquid oil or water, or alcohol such as ethanol, in which methoxypyrazine shown in Formula 1 has been dissolved, onto the Allium vegetables after the above-mentioned hot air drying. The method for adding methoxypyrazine represented by formula 1 is not limited to the above-mentioned method, and various methods are of course possible.

[0030] ─Allium vegetables─ Representative examples of Allium vegetables in the present invention include welsh onion, scallion, garlic, onion, shallot, chive, leek, shallot, tree onion, chives, chives, etc. Of course, both cultivated and wild-growing vegetables are also acceptable.

[0031] In particular, the present invention can be suitably used with leeks, which are vegetables of the Allium genus. For example, a wide variety of leeks can be used, including white leeks such as Senju leeks, Kaga leeks, and Shimonita leeks, green leeks (leaf leeks) such as Kujo leeks and Hakata banno leeks, intermediate types such as Chotsu leeks, red leeks, green onions, chives, and leeks. Dried leeks are particularly suitable for use.

[0032] A method for producing dried green onions will be described below. When producing dried green onions, not only the leaf sheath portion but also the leaf blade portion is often produced as shown in Figure 1, but the present invention can also be used in such cases. Furthermore, when washing fresh green onions after harvesting, they are washed with water or the like, but it is preferable to wash them immediately after harvesting or to wash them after removing the roots and tips of the leaf blades.

[0033] Next, the green onions after washing are cut as follows. As for the cutting direction, in addition to cutting perpendicular to the growth direction of the green onions, they may also be cut diagonally. Specifically, a method of cutting the green onions so that the angle between the growth direction of the green onions and the cut surface is about 25° or more can be used. In addition to cutting perpendicularly or diagonally to the growth direction, cutting along the growth direction of the green onions is also possible. Cutting can be done by hand with a kitchen knife or other tool, or with a slicer. The width of the cuts may be constant or may be varied. Specifically, a wide range of cutting widths from about 2 mm to 30 mm is possible. A cut width of about 5 mm to 15 mm is particularly preferable.

[0034] This process may also include a sterilization step using an aqueous sodium hypochlorite solution. In this case, for example, fresh green onions from which the roots and tips of the leaf blades have been removed are immersed in an aqueous solution of about 150 to 250 ppm sodium hypochlorite for about 10 to 20 minutes, and then washed with water. The hypochlorite treatment may be carried out either before or after cutting the green onions.

[0035] ─Drying method─ The flavor-enhancing effect of the present invention on Allium vegetables can be applied to fresh Allium vegetables, but is particularly suitable for dried Allium vegetables. Generally, drying methods used in the production of Allium vegetables, such as leeks, include hot air drying, freeze-drying, vacuum drying, and microwave drying. The present invention can be applied to any of these drying methods, but is particularly suitable for hot air drying and freeze-drying.

[0036] In addition, in the hot air drying method, treatment is usually possible if there is a dryer that supplies hot air, so drying can be achieved with simple equipment. For example, hot air drying can be carried out at a temperature of about 30°C to 90°C. The hot air drying time is not particularly limited, but is carried out until the moisture content reaches about 5 to 15% by weight. The hot air drying time is not particularly limited, but is generally about 4 to 10 hours at a temperature of about 40°C to 80°C.

[0037] The hot air drying can also be performed in two stages, such as by first drying at a temperature of about 80 to 60°C and then continuing to dry at a slightly lower temperature of 70 to 50°C. In the case of freeze-drying, a method in which the product is blanched with steam or the like, then frozen, and then dried under reduced pressure (usually a vacuum of 0.8 Torr or less) at a shelf temperature of 50°C to 80°C for approximately 14 to 24 hours can be mentioned. However, the above drying methods are merely examples, and the present invention is not limited to any particular drying method.

[0038] -Flavor enhancer for allium vegetables- The flavor improver for Allium vegetables of the present invention is an agent that improves the flavor of raw or dried Allium vegetables used, or is used in foods containing Allium vegetables to improve the flavor of the contained Allium vegetables. In other words, the term "improvement" in the flavor enhancer for Allium vegetables of the present invention means enhancing the flavor of the Allium vegetables when the Allium vegetables already have a flavor of their own.

[0039] In particular, the use of methoxypyrazine in the present invention can improve the natural flavor of Allium vegetables. In addition to the effect of improving the flavor of Allium vegetables, in the case of dried Allium vegetables, the effect of reducing the dry odor peculiar to the dried product may also be achieved. Furthermore, when the methoxypyrazine of the present invention is used on hydroponically grown leeks (fresh or dried), it may have the effect of making the flavor of the leeks closer to that of soil-grown leeks.

[0040] Furthermore, the flavor improver of the present invention is sufficient as long as it contains at least the methoxypyrazine represented by formula 1, and of course may also contain other ingredients such as various oils and fats, solvents, fragrances, seasonings, etc. Furthermore, the form of the flavor enhancer for Allium vegetables does not necessarily have to be one stored in a predetermined type of container, etc., but rather, when producing a food containing Allium vegetables, it is sufficient that a material (various ingredients for addition, such as powder or granules) containing at least methoxypyrazine represented by Formula 1 is present to enhance the flavor of the Allium vegetables, and the material falls within the flavor enhancer for Allium vegetables of the present invention if it is added or mixed with the Allium vegetables themselves or with the food containing Allium vegetables during production or consumption. Of course, the flavor enhancer may also be appropriately blanched with steam or the like before drying.

[0041] ─Addition to Allium vegetables─ There are various methods for adding the methoxypyrazine represented by formula 1 to Allium vegetables. When adding to raw Allium vegetables, it can be added to the Allium vegetables after or before cutting. Various methods of addition are possible, such as spraying. Next, when adding to dried Allium vegetables, in addition to the "drying treatment" step, methoxypyrazine represented by formula 1 can be added as an additive to the dried Allium vegetables after drying. It is also possible to add it before drying. The amount of addition to Allium vegetables is not particularly limited, but in the case of dried green onions, it is generally about 10 ppt to 500 ppm, preferably 100 ppt to 10 ppm, and more preferably 1 ppb to 1 ppm.

[0042] -Allium vegetables containing methoxypyrazine represented by formula 1- The present invention also contemplates Allium vegetables (particularly dried Allium vegetables) containing methoxypyrazine represented by formula 1. Here, dried leek containing methoxypyrazine represented by formula 1 includes, firstly, cases where methoxypyrazine represented by formula 1 is added to fresh Allium vegetables or during the manufacturing process of dried Allium vegetables.

[0043] Furthermore, for example, when processed foods such as instant noodles or instant rice are seasoned with methoxypyrazine at the time of consumption, and the consumer opens the accompanying soup pack or the like to add the seasoning, if the soup pack or the like contains methoxypyrazine shown in formula 1, and if Allium vegetables are used as dried ingredients in the instant noodles or the like, and if dried green onions or green onions reconstituted in hot water and methoxypyrazine shown in formula 1 are present at the time of consumption, then Allium vegetables containing methoxypyrazine shown in formula 1 are present. Furthermore, the methoxypyrazine represented by formula 1 to be added does not necessarily have to be purified, and it goes without saying that any form of flavoring, food material, etc. containing methoxypyrazine represented by formula 1 as a part of its component is included. -Method for producing dried Allium vegetables, including a step of adding methoxypyrazine represented by formula 1- The present invention also contemplates a method for producing dried Allium vegetables, which includes a step of adding (containing) methoxypyrazine represented by formula 1 during the production process of dried Allium vegetables, with the aim of improving the flavor of the Allium vegetables. That is, any step in the process of producing dried Allium vegetables may include a step of incorporating methoxypyrazine represented by formula 1. There are no limitations on the amount used, but when used on dried Allium vegetables, it is preferable to prepare an amount that is roughly the same as the amount added to the dried Allium vegetables described above. -Method for improving the flavor of Allium vegetables by using methoxypyrazine represented by formula 1- The present invention also contemplates a method for improving the flavor of Allium vegetables by incorporating or adding methoxypyrazine represented by formula 1 for the purpose of improving the flavor of Allium vegetables. [Example]

[0044] Examples of the present invention will be described below, but it goes without saying that the present invention is not limited to these examples.

[0045] [Test Example 1] Confirmation of the effect of 2-sec-butyl-3-methoxypyrazine on dried green onions and examination of its concentration The effect of adding 2-sec-butyl-3-methoxypyrazine to dried Allium vegetables, including dried Welsh onion, was investigated. Commercially available 2-sec-butyl-3-methoxypyrazine was used. How to prepare dried green onions Commercially available fresh green onions (Kujo green onions) were cut off to a 5mm section at the root, and then soaked in sodium hypochlorite. After soaking, the green onions were cut into 5mm pieces and then cut into pieces. The cut green onions were washed under running water for 30 minutes, thoroughly drained, and then placed on a tray and placed in a hot air drying device. They were dried at 70°C for 50 minutes, and then further dried at 60°C for 4 hours. After drying, 2-sec-butyl-3-methoxypyrazine was added to the dried green onions in each test group at the concentration shown in Table 1, and the dried green onions were subjected to the following sensory evaluation.

[0046] Sensory evaluation method for dried green onions 100g of boiling water was poured over 1g of the dried green onion, and the green onion was subjected to a sensory evaluation. The evaluation was conducted by five experienced panelists, who evaluated the following points. The effect of improving the green onion flavor was evaluated by sensory evaluation of the flavor of the dried green onions of each test example. The evaluation was conducted from the viewpoint of improving the green onion flavor, and it was determined whether or not the test example had an effect of improving the natural flavor of the green onion. The evaluation results were given with a higher numerical value, the greater the effect of improving the green onion flavor. The evaluation was carried out on a 7-point scale, with the following evaluation criteria: (1 point: bad ⇔ 7 points: good).

[0047] Evaluation criteria 7 points: The natural flavor of green onions is very strong. 6 points: The natural flavor of green onions is strongly felt. 5 points: The natural flavor of green onions is slightly strong. 4 points: Equivalent to control 3 points: The natural flavor of the green onions is slightly lost. 2 points: The natural flavor of the green onions is lost. 1 point: The natural flavor of the green onions is greatly diminished. The evaluation results are shown in Table 1. The evaluation was the average score of the five evaluations.

[0048] [Table 1] It was found that the use of 2-sec-butyl-3-methoxypyrazine improved the green onion flavor of dried green onions. [Test Example 2] Examination to confirm the effect of 2-sec-butyl-3-methoxypyrazine on Allium vegetables other than onion The effect of adding 2-sec-butyl-3-methoxypyrazine to Allium vegetables other than dried leeks was investigated. The Allium vegetables used were chives, onions, and garlic, and the test conditions were the same as in Test Example 1. The results are shown in Table 2.

[0049] [Table 2] It was found that the use of 2-sec-butyl-3-methoxypyrazine improved the flavor of dried chives, dried onions, and dried garlic.

[0050] [Test Example 3] Examination of the effects of other methoxypyrazines on dried leeks The effects of using 2-ethyl-3-methoxypyrazine, 2-isopropyl-3-methoxypyrazine, and 2-isobutyl-3-methoxypyrazine as methoxypyrazines other than the 2-sec-butyl-3-methoxypyrazine used in Test Example 1 on dried green onions were investigated. The test conditions were the same as in Test Example 1. The concentration was adjusted to 10 ppb for dried green onions. The results are shown in Table 3.

[0051] [Table 3] It was also confirmed that 2-ethyl-3-methoxypyrazine, 2-isopropyl-3-methoxypyrazine, and 2-isobutyl-3-methoxypyrazine, as methoxypyrazines other than 2-sec-butyl-3-methoxypyrazine, were also effective.

Claims

1. A flavor enhancer for vegetables of the genus Allium (excluding dried vegetables of the genus Allium) containing, as an active ingredient, methoxypyrazine represented by the following general formula 1: General formula 1: 【Chemistry 1】 [wherein R1 represents a C2-C4 alkyl group, and R2 represents hydrogen or a methyl group]

2. A method for producing Allium vegetables (excluding dried Allium vegetables), comprising the step of adding methoxypyrazine represented by the following general formula 1: General formula 1: 【Chemistry 2】 [wherein R1 represents a C2-C4 alkyl group, and R2 represents hydrogen or a methyl group]

3. Vegetables of the genus Allium to which methoxypyrazine represented by the following general formula 1 has been added (however, dried vegetables of the genus Allium are excluded). General formula 1: 【Transformation 3】 [wherein R1 represents a C2-C4 alkyl group, and R2 represents hydrogen or a methyl group]

4. A method for improving the flavor of Allium vegetables (excluding dried Allium vegetables), characterized by utilizing a methoxypyrazine represented by the following general formula 1: General formula 1: 【Chemistry 4】 [wherein R1 represents a C2-C4 alkyl group, and R2 represents hydrogen or a methyl group]

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