JP2008099608A - Natural soybean seed highly containing isoflavone aglycone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide natural soybean seeds highly containing isoflavone, and to provide a processed food product using the seeds. <P>SOLUTION: The soybean seeds are exposed to seedpod harmful insects after a flowering period. In the soybean seeds, a damaged part caused by ingestion of seedpod harmful insects is preferably one-third or above of whole grains, and a sort having high total isoflavone content, such as "Akisengoku" and "Nishimusume" is preferably used. The content of isoflavone aglycone contained in the soybean seeds is ≥100 μg/g. The soybean seeds highly containing isoflavone are free from denaturation of soybeans, runoff of nutriment, and contamination of impurities excluding soybeans because of requiring no special artificial treatment. Furthermore, as a conventional production method for soybean processed food can be applied as it is, the soybean seeds are usable as a material of processed food product. The soybean seeds are suitable especially for the material of functional food which contains soybean isoflavone causing less individual differences and excellent in internal absorption. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a natural high isoflavone-containing soybean seed by exposure to a fruit pest and a processed food using the same.

Isoflavone is a kind of flavonoid widely distributed in the plant kingdom, and is abundant in legumes, particularly soybean seeds. Recently, isoflavones have been shown to have various pharmacological actions. For example, isoflavone has been shown to exhibit a weak estrogen action by binding to an estrogen receptor, and an improvement effect on climacteric disorders such as osteoporosis due to disturbance of hormone balance in menopausal women has been reported (Non-patent Document 1). . In addition, pharmacological actions such as antioxidant action (Non-patent document 2), cancer cell growth inhibitory action (Non-patent document 3), serum cholesterol concentration lowering action (Non-patent document 4) have been reported, lifestyle-related diseases, It is attracting attention as a functional ingredient for menopause.
J. et al. Nutr. , 125, 567-569 (1995) J. et al. Agric. Food Chem. , 24, 1174-1177 (1976) J. et al. Biol. Chem. , 262, 5592-5595 (1987) Abstracts of Annual Meeting of the Japanese Society for Agricultural Chemistry, p. 118 (2005)

Isoflavones can be broadly classified into aglycones and glycosides bound with sugars based on their structures. Isoflavones contained in soybean seeds are aglycone daidzein, genistein, glycitein and their glycosides daidin, genistin, glycitin, malonyl daidzin, malonylgenistin, malonyl glycitin, acetyl daidine, acetylgenistine, acetylglycitin However, it is glycoside that is the main component, and the content (weight ratio) of aglycone is only 1 to 2%.

According to research on digestion and absorption of isoflavones, isoflavone glycosides are ingested and then metabolized into aglycones and absorbed, but it is known that there are individual differences in metabolism in the body . Moreover, it has been clarified that aglycone is superior to glycosides in the absorption of isoflavones in humans (Non-Patent Document 5).
J. et al. Nutr. , 130, 1695-1699 (2000)

Therefore, in order to enhance the absorption of isoflavones into the body and improve health functionality, development of technology for removing sugars from isoflavone glycosides contained in soybeans and soybean foods and converting them into aglycones is underway. Examples of the invention related to this include the following patent documents.
JP 2001-204486 A JP 2002-288 JP2003-70439 JP 2005-34145 A JP-A-2005-224162

However, any of the above methods is a process for producing food, and requires artificial treatment such as enzyme treatment (Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 5) or acid addition treatment (Patent Document 4). However, not only are there problems in workability and economic efficiency, but also the deterioration of soybeans, the loss of soybean nutrients, and the mixing of components other than soybeans are unavoidable.

It is an object of the present invention to provide a natural high isoflavone aglycone-containing soybean seed by exposure to a fruit pest.

Another object of the present invention is to provide a processed food using a natural high isoflavone-containing soybean seed.

In order to solve the above-mentioned problems, the inventors have investigated the content of isoflavone aglycone in soybean seeds cultivated under various conditions, and as a result, soybean seeds damaged by seed pests have an isoflavone aglycone content. Found that there is a high tendency. The gist of the present invention based on such findings is as follows.

[Invention 1]
A natural soybean seed with a high isoflavone aglycone content, which is obtained by giving damage stress by exposing to soybean pests during enlargement and maturation of soybean seeds.

[Invention 2]
The soybean seed according to invention 1, comprising 150 μg or more of isoflavone aglycone (daidzein, genistein, glycitein) per 1 g of soybean seed.

[Invention 3]
The soybean seed according to the invention 1 using the soybean cultivar "Akisengok" or "Nishimusume" having a high total isoflavone content.

[Invention 4]
Processed food containing high isoflavones using the soybean seeds of Invention 1, Invention 2 or Invention 3 as a raw material.

The present invention has the following practical effects and advantages.
(1) The soybean seed of the present invention contains at least 100 μg / g of isoflavone aglycone. This corresponds to 4 to 11 times the amount contained in normal soybean seeds.
(2) Since this high isoflavone aglycone-containing soybean seed does not depend on industrial treatment, there is no deterioration of soybean, loss of soybean nutrients, mixing of components other than soybean.
(3) By using this soybean seed as a raw material, a food with a high isoflavone aglycone content can be produced. Processed foods containing high isoflavone aglycone have a high metabolic absorption rate when fed. Therefore, even if the amount is the same as that of a normal processed soybean food, it is an excellent health functional food.

The soybean seeds of the present invention are those that have been subjected to damage stress due to feeding damage of the seedling pests by exposing to the seedling pests after the flowering period, and actually stopping the application of the chemicals for pest control. is there.

It is not always clear why damage stress caused by pests increases the isoflavone aglycone content in soybean seeds, but damage caused by pests caused by pests induces a pest repellent response (phytoalexin reaction) that is latent in soybeans. As a result, it is presumed that the sugar chains of isoflavone glycosides in soybean seeds are eliminated and the isoflavone aglycone content is increased.

The insect pest may be any insect that damages soybean seeds. Examples include sucking pests such as Hosohelikamushi, Ichimonjimamemushi, Minamiokakamemushi, Aokusakamamemushi, and food-damaging pests such as white spotted moth, Messinigaiga.

In order to stably obtain soybean seeds with a high isoflavone aglycone content, the damaged part due to the feeding of the seed pests should be more than one third of the whole grain in terms of the area or shape of the discolored part of the seed surface Is preferably selected.

The present invention is not limited to specific soybean varieties, and the effect is recognized even in cultivated varieties. In order to increase the content of isoflavone aglycone, varieties having a high total isoflavone content including isoflavone glycosides are preferred. Preferable varieties include, for example, “Akisengok” and “Nishimusume”.

The soybean seeds of the present invention have an increased isoflavone aglycone content even without artificial treatment such as enzyme treatment or acid treatment. The aglycone content per 1 g of soybean seeds is at least 150 μg / g or more, and the varieties having a high total isoflavone content easily reach 300 μg / g.

In order to obtain a processed food from the soybean seeds of the present invention, the usual method for producing a processed soybean food can be applied as it is. Moreover, it can utilize effectively by grind | pulverizing and pulverizing. By adding treatments such as solvent extraction and purification, it can also be used as a highly functional health food, cosmetics, or a pharmaceutical material.

Examples of processed foods using the soybean seeds of the present invention include soy milk and tofu. Ordinary foods, nutritional foods, functional foods and the like can be used in appropriate combination. Furthermore, as the food form, solid, liquid, powder, granule, etc. can be selected. In the case of health food, the dosage form can be arbitrarily shaped, such as a doublet or a capsule, if necessary.

The soybean seeds of the present invention can also be used as a raw material for producing a food material containing a high isoflavone aglycone by industrial treatment. In that case, the object can be achieved with a smaller amount than in the past.

In the plains of Miyazaki Prefecture, seven soybean varieties, “Akisengok”, “Axiromome”, “Ichihime”, “Elster”, “Sachiyutaka”, “Toyoshirome” and “Nishimusume” were cultivated. The sowing time, planting density, fertilizer amount, etc. were in accordance with the customary cultivation conditions in the region. Here, in order to expose soybean seeds to the seed pests, the spraying of chemicals for pest control was stopped after the flowering period, and the pest density in the field was kept high. More than half of the harvested soybean seeds were damaged by seed pests. Soybean seeds having a damage ratio of 1/3 or more of the whole grain were selected from them, and the isoflavone content was analyzed.

Cultivation was carried out under the same conditions as in Example 1 except that pest control was carried out by chemical spraying throughout the cultivation period. The isoflavone content was analyzed for the harvested soybean seeds. In addition, 10% or less of the harvested soybean seeds were damaged by the fruit pests.

Each sample was pulverized with a centrifugal pulverizer, pulverized, 10 times the amount of 70% ethanol was added, and the sample left at room temperature for 18 hours was centrifuged, and the collected supernatant was subjected to high performance liquid chromatography analysis. The collected supernatant was injected into ODS-AM-303 (4.6 mm × 250 mm, YMC). The detector used was RF-10Axl (Shimadzu Corporation), and the measurement wavelength was 260 nm. Elution is performed by a gradient elution method, and the initial conditions of the moving bed are set as liquid A (acetonitrile: acetic acid = 1000: 1): liquid B (water: acetic acid = 1000: 1) = 15: 85, and the concentration of liquid B is linear. 50 minutes later, A liquid: B liquid = 35: 65. The mobile phase flow rate was 1.0 ml per minute. The results of the analysis are shown in Table 1.

Table 1. Comparison of the content of isoflavone glycosides and aglycones in soybean seeds exposed to pests and normal (unexposed) soybean seeds and the percentage of total isoflavones

表１から明らかなように、莢実害虫に暴露した大豆種子のイソフラボンアグリコン含有量は、いずれの品種においても通常（無暴露）の大豆種子と比較して顕著に高い値を示した。すなわち、アグリコン含有量は、莢実害虫に暴露した大豆種子が１８〜６０μｇ／ｇであったのに対し、通常の大豆種子では１５６〜３８１μｇ／ｇの範囲にあった。

As is clear from Table 1, the content of isoflavone aglycone in soybean seeds exposed to the seed pests was significantly higher in all varieties than in normal (unexposed) soybean seeds. That is, the aglycone content was 18 to 60 μg / g for soybean seeds exposed to the seed pests, while it was 156 to 381 μg / g for normal soybean seeds.

Five times the amount of water was added to the soybean seed (variety: Nishimusume) powder of Example 1 and Example 2 and homogenized, and filtered through two layers of gauze to prepare raw soymilk. Ethanol was added to the obtained raw soymilk to a concentration of 70%, left at room temperature for 18 hours, centrifuged, and the recovered supernatant was analyzed for isoflavone content. The analysis of the isoflavone content is the same as in Example 1 and Example 2 above. The results of the analysis are shown in Table 2.

Table 2. Comparison of the content of isoflavone glycosides and aglycones in soybean milk prepared using soybean seeds exposed to pests and normal (unexposed) soybean seeds and the percentage of total isoflavones

表２から明らかなように、莢実害虫に暴露した大豆種子を用いて調製した豆乳のイソフラボンアグリコン含有量は、通常の大豆種子を用いたものと比較して顕著に高い値を示した。すなわち、イソフラボンアグリコン含有量は、通常の大豆種子が２９μｇ／ｇであったのに対し、莢実害虫に暴露した大豆種子では１５５μｇ／ｇであった。

As is clear from Table 2, the isoflavone aglycone content of soy milk prepared using soybean seeds exposed to the seed pests was significantly higher than that using ordinary soybean seeds. That is, the content of isoflavone aglycone was 29 μg / g for normal soybean seeds, whereas it was 155 μg / g for soybean seeds exposed to seed pests.

The natural high isoflavone aglycone-containing soybean seed of the present invention can be used as a raw material for highly functional health foods. The extracted and purified isoflavone aglycone can also be used as cosmetics and pharmaceutical materials.

Claims (4)

大豆 Soybean seeds containing natural high isoflavone aglycone by exposure to real pests. The soybean seed according to claim 1, comprising 150 μg or more of isoflavone aglycone per 1 g of seed. The soybean seed according to claim 1, wherein the variety "Akisengok" or "Nishimusume" is used. Processed food containing high isoflavones using the soybean seed of claim 1, claim 2 or claim 3 as a raw material.