JP2011132144A - Extract containing grain-derived proanthocyanidin and production process therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for extracting proanthocyanidin from grains, and to provide an extract of grains containing proanthocyanidin. <P>SOLUTION: An extract containing proanthocyanidin is obtained by extraction of grains, particularly, soy beans, and more particularly, a seed coat thereof as a raw material with an organic acid-containing aqueous solution. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a proanthocyanidin-containing extract obtained from cereal grains containing proanthocyanidins, particularly soybeans, and seed coats thereof, and a method for producing the same.

  Conventionally, it has been reported that proanthocyanidins have excellent physiological actions such as antioxidant action, anticancer action, thrombus formation inhibitory action, platelet aggregation inhibitory action, etc., active pharmaceutical ingredients and functional foods It has been found that it is useful as a raw material of (see, for example, Patent Document 1).

  So far, proanthocyanidins are known to be contained in grape seeds, pericarps, fruits, etc., and can be obtained by subjecting the plant parts to raw materials and extraction treatment using hot water or organic solvents as extraction solvents. (For example, refer patent document 2).

  In addition to the plant parts, it is known that proanthocyanidins are contained in soybeans such as black beans and tea beans, and grains such as red rice, sorghum and barley. However, as a result of research by the present inventors, the above-mentioned cereals, particularly soybeans, and also the seed coats thereof are extracted using a solvent used to extract proanthocyanidins from grape seeds, ie, hot water or an organic solvent as an extraction solvent. It was found that proanthocyanidins could not be obtained efficiently if subjected to (see Comparative Example 1, Reference Examples 2 and 4 in this specification).

  Conventionally, a method for extracting proanthocyanidins from grains containing proanthocyanidins by a method suitable for use in the food field has not been reported so far.

JP 2003-128560 A Japanese Patent Laid-Open No. 11-80148

  An object of the present invention is to provide a technique for extracting proanthocyanidins from grains containing proanthocyanidins, particularly soybean seed coats such as black soybeans and brown soybeans, and a grain extract containing proanthocyanidins.

  The present inventors diligently studied to solve the above-mentioned problems, and proanthocyanidins can be efficiently extracted by using a grain containing proanthocyanidins as a raw material and subjecting it to an extraction treatment with an organic acid-containing aqueous solution. I found. In addition, the proanthocyanidin-containing cereal extract obtained by such an extraction treatment contains proanthocyanidins having a low polymerization degree, and has been found to be useful as an active ingredient of pharmaceuticals and a raw material for functional foods. The present invention has been completed by further studies based on these findings.

That is, the present invention provides the following aspects of the invention:
Item 1. A proanthocyanidin-containing extract obtained by subjecting a grain containing proanthocyanidins to an extraction treatment with an aqueous solution containing an organic acid.
Item 2. Item 2. The proanthocyanidin-containing extract according to Item 1, wherein the cereal is soybean seed coat.
Item 3. Item 3. The proanthocyanidin-containing extract according to Item 1 or 2, wherein the extraction treatment is performed under a temperature condition of 90 to 105 ° C.
Item 4. A method for producing a proanthocyanidin-containing cereal extract, comprising a step of extracting a cereal containing proanthocyanidins with an organic acid-containing aqueous solution.
Item 5. Item 5. The method for producing an extract containing proanthocyanidins according to Item 4, wherein the cereal is soybean seed coat.
Item 6. Item 6. The method according to Item 4 or 5, wherein the extraction treatment is performed under a temperature condition of 90 to 105 ° C.
Item 7. (i) a method for producing proanthocyanidins, comprising: a step of extracting a grain containing proanthocyanidins with an organic acid-containing aqueous solution; and (ii) a step of purifying proanthocyanidins from the proanthocyanidin-containing extract obtained in the above step. .
Item 8. Item 8. The method according to Item 7, wherein the cereal is soybean seed coat.
Item 9. Item 9. The production method according to Item 7 or 8, wherein the extraction treatment is performed under a temperature condition of 90 to 105 ° C.

  According to the present invention, proanthocyanidins, particularly proanthocyanidins having a low polymerization degree, can be efficiently extracted from cereals containing proanthocyanidins, and a cereal extract containing proanthocyanidins can be obtained. A cereal extract containing proanthocyanidins has excellent physiological activities such as an antioxidant action, an anticancer action, a thrombus formation inhibitory action, and a platelet aggregation inhibitory action, and is useful as a compounding ingredient for pharmaceuticals and foods. In particular, soybean seed coats have a high proanthocyanidin content (particularly, a low polymerization degree proanthocyanidin content), and proanthocyanidin-containing extracts obtained from soybean seed coats are particularly useful.

  Further, according to the present invention, proanthocyanidins can be extracted using an organic acid that can also be used as a food material. Therefore, the extract obtained in the present invention is highly safe and suitable for food applications. is there.

I. Production method of proanthocyanidin-containing cereal extract In the production method of the present invention, the raw material is not particularly limited as long as it is a cereal containing proanthocyanidins. For example, soybean, red rice, sorghum, barley and the like Illustrated. Among these, soybean is particularly preferable.

  In the production method of the present invention, when soybean is used as a raw material, the type of soybean is not limited, but black soybean and brown soybean are preferred. In particular, soybean seed coats, especially black soybean seed coats, have a high proanthocyanidin content (particularly, a low-polymerization degree proanthocyanidin content) and are more suitable raw materials.

  In the production method of the present invention, when soybean seed coat is used as a raw material, soy seed coat other than seed coat such as cotyledon, bud, radix, hypocotyl, etc. is included, as long as soybean seed coat is included. It may be.

  In the present invention, as the raw material to be subjected to the extraction treatment, it is possible to use untreated cereal grains or those subjected to pretreatment such as drying, roasting, chopping and crushing as necessary. In particular, when soybean, particularly soybean seed coat, is used as a raw material, the raw odor and blue odor derived from soybean can be reduced by roasting, and therefore, as a pretreatment of the raw material used in the production method of the present invention. Roasting is preferred.

  In the production method of the present invention, an organic acid-containing aqueous solution is used as an extraction solvent. Examples of the organic acid used as the extraction solvent include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, citric acid, lactic acid, malic acid, succinic acid, isobutyric acid, isovaleric acid, caproic acid, ascorbic acid, Examples include glutamic acid, gluconic acid, tartaric acid, fumaric acid and the like. Among these, preferably, acetic acid, citric acid, lactic acid, malic acid, succinic acid, ascorbic acid, glutamic acid, gluconic acid, tartaric acid, and fumaric acid are used, and more preferably acetic acid and citric acid are used. Proanthocyanidins can be extracted more efficiently by using these organic acids.

  In the present invention, vinegar may be used as the organic acid. Examples of vinegar include fruit vinegar such as apple vinegar and grape vinegar, and grain vinegar such as rice vinegar.

  In this invention, the said organic acid may be used individually by 1 type, and may be used in combination of 2 or more types arbitrarily. From the viewpoint of more efficiently extracting proanthocyanidins, an example of a suitable embodiment of the extraction solvent is an aqueous solution containing acetic acid and apple cider vinegar.

  In the organic acid-containing aqueous solution used as the extraction solvent, the content ratio of the organic acid varies depending on the type of the organic acid used and cannot be uniformly defined. Usually, however, the total amount of the organic acid is relative to the total amount of the aqueous solution. 0.001 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.1 to 2% by weight. In addition, when using vinegar as an organic acid, the organic acid content contained in the used vinegar is set so that the said range may be satisfied.

  The pH of the organic acid-containing aqueous solution is appropriately adjusted according to the type and concentration of the organic acid, but is usually 1.8 to 8, preferably 1.8 to 6, and more preferably 1.8 to It is desirable to adjust to 4. Such pH adjustment can be performed by known means.

  In addition, the organic acid-containing aqueous solution is further improved in terms of the convenience of reaching the temperature reached at the time of extraction, the safety of the extraction operation, the peculiarity of the extraction apparatus, and the post-extraction removal operation from the viewpoint of increasing extraction efficiency From the viewpoint of complexity, safety when using foods, etc., it is desirable not to include an organic solvent.

  In the present invention, the grain extraction treatment with an organic acid-containing aqueous solution is usually at 25 ° C. or higher, preferably 50 ° C. or higher, more preferably 75 ° C. or higher, more preferably 90 ° C. or higher, particularly preferably 90 to 105 ° C. Done under. Proanthocyanidins can be efficiently extracted by subjecting the grains to extraction using such temperature conditions and the extraction solvent.

  In the present invention, the amount (weight ratio) of the extraction solvent relative to the raw material (dry weight) to be subjected to the extraction treatment is not particularly limited, but is usually 1 to 200 times, preferably 10 to 100 times, more preferably. A 10-50 times amount is illustrated.

  Moreover, the grain extraction treatment with the organic acid-containing aqueous solution can be carried out according to the extraction treatment method employed in the preparation of ordinary plant extracts. Specific examples of the extraction treatment method include an immersion method and a percolation method. The extraction process can be performed using a known extractor.

  In the extraction process of grains with an organic acid-containing aqueous solution, the extraction time is appropriately set according to the type of extraction solvent used, the extraction method, and the like, but is usually 10 to 120 minutes, preferably 15 to 60 minutes, and more preferably. Is exemplified for 15 to 30 minutes.

  Thus, by performing the extraction treatment, proanthocyanidins are extracted from the grains into the extraction solvent, and after the extraction treatment, an extract containing proanthocyanidins can be obtained by solid-liquid separation and collecting the liquid fraction. . For example, when soybean seed coat is used as a raw material, 0.7 to 2.0% by weight based on the total weight of the soybean seed coat used as a raw material is 1 in the preferred conditions. Proanthocyanidins corresponding to about 7 to 2.0% by weight can be extracted. Further, by performing the extraction treatment in this manner, it corresponds to about 0.1 to 0.3% by weight per total weight of soybean seed coat as a raw material, and about 0.2 to 0.3% by weight under preferable conditions. A low degree of polymerization proanthocyanidins having a degree of polymerization of 2 to 3 can be extracted.

  The extract containing proanthocyanidins obtained by the above extraction treatment is in a liquid state, but can be subjected to a treatment such as concentration and drying, if necessary, to form a concentrate or a dried product.

  Further, the extract containing proanthocyanidins thus obtained was further purified to a desired purity by subjecting it to a conventional purification step such as a countercurrent distribution method, liquid chromatography or the like. Proanthocyanidins can also be obtained.

II. Proanthocyanidin-containing cereal extract The proanthocyanidin-containing extract derived from cereal obtained by the above production method usually contains 2 to 5% by weight of proanthocyanidins, preferably about 3 to 5% by weight, based on the dry weight of the extract. is doing.

  When soybean seed coat is used as a raw material, in the proanthocyanidin-containing extract obtained by the above production method, among the total proanthocyanidins, those having a low polymerization degree of 2 to 3 are about 8 to 24% by weight. is occupying. That is, when soybean seed coat is used as a raw material, about 0.2 to 0.9% by weight of proanthocyanidins having a low polymerization degree is usually contained per proanthocyanidin-containing extract obtained by the above production method.

  The proanthocyanidin-containing extract obtained by the above production method can exhibit excellent physiological activity due to the action of proanthocyanidins, particularly proanthocyanidins having a low polymerization degree, and other extractive components. Specifically, proanthocyanidins have useful physiological actions such as antioxidant action, antimutagenic action, angiotensin I converting enzyme inhibitory action and the like, and proanthocyanidin-containing extracts obtained by the above production method are The useful physiological action of can be effectively exhibited. Therefore, the proanthocyanidin-containing extract obtained by the above production method is useful as an active ingredient of a pharmaceutical preparation, and is also useful as a food material for functional foods, health foods, foods for specified health use, and the like. That is, this invention provides the pharmaceutical or foodstuff (including a drink) containing the effective amount of the proanthocyanidin containing extract obtained by the said manufacturing method from another viewpoint.

  When the proanthocyanidin-containing extract obtained by the above production method is blended in a pharmaceutical preparation, the blending ratio of the extract is not particularly limited, and is appropriately set according to the daily dose. Specifically, the above-described production method for a pharmaceutical preparation is performed so that the daily dose for an adult satisfies, for example, 0.1 to 400 mg, preferably 1 to 300 mg, more preferably 20 to 200 mg in terms of the amount of proanthocyanidins. It is sufficient that the proanthocyanidin-containing extract obtained in (1) is contained. A pharmaceutical preparation containing a proanthocyanidin-containing extract obtained by the above production method is mixed with a base, a carrier, an additive and the like generally used in the pharmaceutical field together with the extract to obtain a desired dosage form. It is prepared by formulating as follows.

  In addition, when the proanthocyanidin-containing extract obtained by the above production method is blended with food (including beverages), the blending ratio of the extract is not particularly limited. For example, the proanthocyanidin content per total amount of food is The protoanthocyanidin-containing extract obtained by the above production method is contained in the food so as to be 0.001 to 10% by weight, preferably 0.001 to 5% by weight, more preferably 0.01 to 0.5% by weight. It only has to be done. The form of the food is not particularly limited, and examples include seasonings such as beverages, gel food, gummi, pudding, baked confectionery, dressing, seasoning sauce, ice cream, ice confectionery, and the like. Examples of suitable food forms include beverages and gel foods. A food containing a proanthocyanidin-containing extract obtained by the above production method is prepared by using a food material, a food additive, or the like as a raw material together with the extract to obtain a desired food form. For example, beverages are mixed with liquid proanthocyanidin-containing extracts obtained by the above production method in a proper amount of sweeteners such as sugar, seasonings such as amino acids, antioxidants such as vitamin C, fruit juice, etc. as necessary. Can be prepared. In addition, the gel-like food is mixed with a liquid proanthocyanidin-containing extract obtained by the above production method, and if necessary, a sweetener, a seasoning, an antioxidant, a colorant, a fragrance, a fruit juice, etc., and agar, It can be prepared by gelation using a gelling agent such as pectin, carrageenan, guar gum, tamarind gum, xanthan gum, locust bean gum or the like.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited by these.

Examples 1 to 19 Production of proanthocyanidin-containing extract Black soybean seed coats were roasted for 3 minutes with stirring at a temperature of 190 ° C., then transferred to another container and cooled or ground without roasting. The black soybean seed coat obtained in this way was added to an extraction solvent and subjected to an extraction treatment under heating conditions. The extraction processing conditions are as shown in Table 1. After the extraction treatment, centrifugation was performed, or the extract was taken out and filtered through a 5 micrometer bag filter to obtain a proanthocyanidin-containing extract.

  The proanthocyanidin content contained in the obtained proanthocyanidin-containing extract was measured by HPLC.

  The results are also shown in Table 1. From this result, even when the extraction treatment is performed using hot water (Comparative Example 1), the extraction efficiency of proanthocyanidins having a polymerization degree of 2 to 3 from the seed coat of black soybean is low, whereas in an aqueous solution containing an organic acid, (Examples 1 to 19) The extraction efficiency of proanthocyanidins having a polymerization degree of 2 to 3 was greatly improved. In particular, when an organic acid is used in combination with apple vinegar and citric acid, the extraction efficiency of proanthocyanidins having a polymerization degree of 2 to 3 has been remarkably improved. When an extraction solvent containing an organic solvent (acetone) and an organic acid (acetic acid) is used (Reference Example 1), an extraction solvent containing no organic solvent and containing an organic acid of the same concentration is used (implementation). Compared to Example 19), the extraction efficiency of proanthocyanidins having a degree of polymerization of 2 to 3 was reduced to about half.

Example 20 Production Example of Beverage The proanthocyanidin-containing extract (liquid form) obtained in Example 1 was added to acesulfame K (final concentration 0.0063 wt%), sucralose (final concentration 0.0053 wt%), flavor (commodity) Name “Multi Enhancer” made by San-Ei Gen FFI Co., Ltd. (final concentration 0.04% by weight), Neo-san Marc (trade name, produced by San-Ei Gen FFI Co., Ltd.), and granulated sugar (final concentration 0.5% by weight) After adding and mixing, after heating to 90 ° C., filling and sealing the container, overturning the container and holding for 1 minute as a container / cap sterilization (conditions satisfying the sterilization condition of soft drinks with a pH of less than 4) The product was cooled to room temperature or lower with cold water and drained to produce a beverage product.

  The thus obtained beverage (the beverage of Example 20) was subjected to sensory evaluation by 10 panelists. The evaluation was carried out by cooling each beverage to 10 ° C., and evaluating the results of drinking in five levels: good, slightly good, normal, slightly bad, and bad. In addition, the sensory evaluation of the proanthocyanidin-containing extract (liquid) itself obtained in Example 1 was performed in the same manner.

  The results are shown in Table 2. From this result, all the panelists evaluated that the beverage of Example 20 is better in taste with respect to the proanthocyanidin-containing extract obtained in Example 1, and the beverage of Example 20 It was improved to a level that is sensuously equivalent to that of a normal beverage.

Example 21 Production Example of Gelled Food The proanthocyanidin-containing extract (liquid) obtained in Example 1 was mixed with fructose 3% by weight and powdered agar (trade name “Yamato”, manufactured by Ina Food Industry Co., Ltd.) 0.5. Weight% was added and heated with stirring until the product temperature reached 85 ° C. After filling and sealing the heated mixed liquid in a suitable cup, the gelled food with moderate jelly-like viscosity was manufactured by cooling with a refrigerator.

  Since the taste and texture are important for the evaluation of gel foods, the panelists of 10 obtained gel foods are evaluated for taste and texture, respectively, and the taste and texture are generally evaluated. A comprehensive evaluation was conducted. In addition, these evaluations ingested the gel-like food with which the cup was filled after cooling to 10 degreeC, and evaluated the result of ingestion in five steps, good, a little good, normal, a little bad, and bad.

  The results are shown in Table 3. From this result, it was confirmed that the gel-like food of Example 21 was good with taste and texture, and was excellent sensory.

Claims (9)

  A proanthocyanidin-containing extract obtained by subjecting a grain containing proanthocyanidins to an extraction treatment with an aqueous solution containing an organic acid.   The proanthocyanidin-containing extract according to claim 1, wherein the cereal is soybean seed coat.   The proanthocyanidin-containing extract according to claim 1 or 2, wherein the extraction treatment is performed under a temperature condition of 90 to 105 ° C.   A method for producing a proanthocyanidin-containing cereal extract, comprising a step of extracting a cereal containing proanthocyanidins with an organic acid-containing aqueous solution.   The method for producing a proanthocyanidin-containing extract according to claim 4, wherein the cereal is soybean seed coat.   The manufacturing method of Claim 4 or 5 with which an extraction process is performed on the temperature conditions of 90-105 degreeC. (i) extracting cereals containing proanthocyanidins with an organic acid-containing aqueous solution; and
(ii) A method for producing proanthocyanidins, comprising a step of purifying proanthocyanidins from the proanthocyanidin-containing extract obtained in the above step.   The production method according to claim 7, wherein the cereal is soybean seed coat.   The production method according to claim 7 or 8, wherein the extraction treatment is performed under a temperature condition of 90 to 105 ° C.