JPH05244889A - Method for treating adzuki bean - Google Patents

Abstract

PURPOSE:To obtain ADZUKI beans reduced in unpleasant feeling such as a bitter taste produced in boiled ADZUKI beans or an ADZUKI bean product using the boiled ADZUKI beans, especially the ADZUKI bean product with hardly any sweetness and, above all, the bitter taste strongly felt in using whole grain ADZUKI beans having the testa or applying heat and preserving the ADZUKI beans for a long period, etc. CONSTITUTION:ADZUKI beans are heated and boiled to provide boiled ADZUKI beans. In the process, the ADZUKI beans are treated with one or two or more enzymes selected from a polyphenol oxidase such as laccase or bilirubin oxidase, a glycoside hydrolase such as naringinase, a glycoside transferase such as transglucosidase, a hydrolase for polysaccharides such as amylase or a proteolytic enzyme such as protease.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Azuki beans are widely used for shiruko, bean paste and the like, but the present invention relates to a method for treating azuki beans, and is particularly used for producing boiled azuki beans.

[0002]

2. Description of the Related Art Azuki beans are usually boiled once and then used for adzuki bean products. To boil red beans, the red beans from which contaminated dust has been removed are washed with water, and if necessary soaked in water to swell, then put in a pot or kettle with water and heated. Traditionally, boiled azuki beans have been sweetened by adding sugar etc. to make red bean products such as shiruko and bean jam. Recently, however, those with a strong sweetness have been disliked, and azuki bean products with weaker sweetness have increased in number.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have found that an adzuki bean product having a low sweetness sometimes causes an unpleasant sensation such as bitterness, particularly when using whole-grain adzuki beans having a skin or at a temperature. I noticed that I often felt it when I added it and kept it for a long time, and I pursued the cause and preventive measures. The unpleasantness such as the bitterness of red beans was not felt by all who ate it, but was felt strongly by some people, and there were individual differences in the way of feeling. Moreover, I felt or did not feel depending on the condition of heating when adzuki beans were boiled and the storage conditions of adzuki bean products. Therefore, although the cause of the problem was extremely difficult to find, it was found that it can be prevented by treating the adzuki bean with an enzyme when it is heated, and the present invention was completed.

When the red beans are boiled, the broth is generally removed once to remove the broth. However, in industrial production where a large amount of red beans are processed at one time, it is difficult to sufficiently wash with water after the removal of the red beans. Taste and astringency are likely to occur. The component showing such unpleasantness such as bitterness has not been clarified, but it is reported that azuki beans contain tannin, phytic acid, anthocyanidins, oxalic acid and the like.

The present invention is intended to remove components showing bitterness and the like which boiled azuki beans have, and by providing boiled azuki beans having no bitterness, an azuki bean product which does not feel unpleasantness such as bitterness is provided. That is also the purpose.

[0006]

According to the present invention, an enzyme treatment is carried out before and after heating red beans for boiling. Enzymes used here include proteolytic enzymes such as proteases, glycoside hydrolases such as naringinase, polysaccharide degrading enzymes such as amylase, glycosyltransferases such as transglucosidase, and polyphenol oxidases such as laccase and bilirubin oxidase. Enzymes selected from two or more species can be used. These enzymes may be used after being separated and purified from microorganisms and the like by a known method, but they are commercially available from many manufacturers as food grade preparations, and it is convenient to use them.

To treat red beans with an enzyme before boiling,
For example, adzuki bean may be added to immersion water when it is previously immersed in water, or it may be removed after immersion, mixed with an enzyme and left for a certain period of time. It can also be carried out by sprinkling the enzyme dispersed in water and allowing it to stand for a predetermined time before being immersed in water. The red beans treated in this way are heated by steaming, simmering, etc. according to a conventional method,
Use boiled red beans.

The treatment with the enzyme may be carried out after the boiling, without being carried out before the boiling. At this time, adding enzyme to hot red beans immediately after boiling may cause inactivation, so cool it a little and treat at a temperature that does not affect the function of the enzyme. It is also possible to treat the red beans before and after boiling. When an adzuki bean product such as shiruko or bean paste was prepared using the boiled adzuki bean thus treated with the enzyme, no unpleasant sensation such as bitterness was felt in the adzuki bean product.

The amount of enzyme added to azuki beans is not generally determined depending on the type of enzyme used, the degree of purification, the titer of enzyme activity, etc., but even when a commercially available enzyme is used, it is 10 times the weight of azuki beans used. 1 / 1,000, preferably 1,000
It is necessary to use more than one-third amount.

The treatment temperature is ideally the optimum temperature of the enzyme used, but the enzyme can be treated at an appropriate temperature of 80 ° C. to room temperature. Also, the treatment time varies depending on the type of enzyme used, the treatment temperature, the titer of enzyme activity, the treatment method, etc., but when treated at a high temperature of 60 to 80 ° C., 30 minutes is desirable, and it is left at room temperature overnight. It is also possible to do so. However, if it is left for too long, it may be adversely affected by the enzyme of adzuki bean itself or the microorganisms adhering to it, which may adversely affect the flavor of adzuki bean. Therefore, it is desirable to treat as short a time as possible.

By treating with the enzyme in this manner, boiled azuki beans without any discomfort such as bitterness were obtained. Furthermore, the red bean product made from this boiled red bean did not feel any discomfort such as the bitterness that red bean has. Moreover, for example, even if the obtained red bean product was stored at a high temperature for a long time with a hot bender or the like, little bitterness or the like occurred.

[0012]

EXAMPLES Next, examples of the present invention will be described. Examples 1 to 5 Pebble and dust contaminated with the adzuki beans as the raw material were removed, washed with water, and then drained. Then, 0.5 parts of each enzyme listed in the table was separately dispersed and dissolved in 200 parts of water to prepare each enzyme solution. Then, 100 parts of each enzyme solution is added.
Each part was spray-added to water-washed red beans and left at 50 ° C. for 2 hours. Next, the red beans treated with each enzyme were separately placed in a pressure-type double kettle, water was added and the mixture was boiled at 105 ° C. for 30 minutes, then the broth was removed, and washed thoroughly with water to obtain boiled red beans.

80 parts of this boiled azuki bean was ground and sieved to remove the skin, and 12 parts of sugar, 50 parts of water, 0.1 part of carrageenan and 20 parts of unbrushed boiled azuki beans and 20 parts of water was added to make a Shiruko drink. Fill the can with this sirko drink liquid, seal it, and let it stand at 130 ° C for 2
It was sterilized by heating for 0 minutes and cooled with water to obtain a canned shiroko drink. These canned shiruko drinks did not feel any discomfort such as bitterness.

Sensory test results The canned sirko drinks described in Examples 1 to 5 were placed in a hot bender adjusted to 60 ° C. and left for 2 months.
As a result of a sensory test by 10 panelists, the results are shown in the table.

[0015]

Regarding the sensory test, the following 5 grades were used to evaluate whether the bitterness or the like was felt when the Shirko drink was consumed, and how strong it was when the feeling was felt, and the evaluation points of 10 panelists were totaled. It is a thing. The number of panelists is about 10
From 0 people, 10 people were selected in descending order of sensitivity to the bitterness of boiled red beans.

Sensory test evaluation stage 1 No bitterness is felt. 2 Feel a slight bitter aftertaste. 3 Slight bitterness, etc., but not too uncomfortable. 4 Feels uncomfortable such as bitterness. 5 I strongly feel discomfort such as bitterness.

Comparative Example 1 is a canned sirko drink using boiled azuki beans, which is prepared by heat-treating azuki beans just washed with water without enzyme treatment, and Comparative Example 2 is water added in place of the enzyme solution. It is a canned Shirko drink using boiled azuki beans that has been left at 50 ° C for 2 hours and then heat-treated.

Example 6 Removing pebbles, dust, etc. contaminated from azuki beans as a raw material,
After washing with water and draining, 1 part of amylase (manufactured by Amano Pharmaceutical Co., Ltd.) was dispersed and dissolved in 500 parts of water, 100 parts of azuki beans was immersed in this, and left at 50 ° C. for 2 hours. Then, the azuki beans were taken out, washed with water, put in a pressure double pot with water, steamed at 120 ° C. for 20 minutes to remove the broth, and washed with water to prepare boiled azuki beans.

The boiled azuki beans were processed in the same manner as in Examples 1 to 5 to prepare a shiko drink liquid, which was filled in a can,
It was sterilized by heating at 0 ° C. for 20 minutes and cooled with water to obtain a canned shiroko drink. No unpleasant sensation such as bitterness was felt in these Shiruko drinks. In addition, put this canned Shiroko drink in a hot-bender,
As a result of sensory test after storage for a month, the total of 10 panelists' evaluation points was 12, most people (8 people) did not feel bitterness, and those who felt bitterness (2
(Name) also felt a slight bitterness in the aftertaste.

Claims (2)

[Claims] 1. When heating azuki beans to boil them,
A method for treating red beans, which comprises treating red beans with an enzyme. 2. The enzyme is a polyphenol oxidase such as laccase or bilirubin oxidase, a glycoside hydrolase such as naringinase, a glycosyltransferase such as transglucosidase, a polysaccharide degrading enzyme such as amylase, and a proteolytic enzyme such as protease. The method for treating azuki beans according to claim 1, wherein one kind or two or more kinds are selected from the above.