JPS6129694B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an aqueous solution for removing astringency from persimmons, chestnuts, etc.

[Conventional technology]

The inventors previously reported in Patent Application No. 214847 filed in 1981 that a mixed aqueous solution of ethyl alcohol and acetic acid obtained by adding a few hundredths of a mole of acetic acid to an aqueous solution of ethyl alcohol such as shochu, It was demonstrated that high quality persimmons and chestnuts without astringency can be obtained by removing astringency from persimmons and chestnuts.

[Problem that the invention seeks to solve]

Later, when this method was widely applied to domestic persimmons, it was found that some astringent persimmons could not be expected to have any practical effects. Examples include Yokono persimmons from the Shimonoseki region of Yamaguchi Prefecture, Atago persimmons from Ehime Prefecture, Hagakure persimmons from Saga Prefecture, and Shibu persimmons from highlands. Although these meats are recognized to have excellent meat quality, it is difficult to remove the astringency, so most of them undergo a general short-term process to remove the astringency.
The reality is that instead of producing fresh de-astringent persimmons, persimmons are dried in the sun for a long period of time to remove astringency and are sold as kushi-gaki or korogaki.

The inventors have arrived at the present invention as a result of various studies on these difficult-to-remove astringency persimmons, focusing on the above-mentioned ethyl alcohol-acetic acid aqueous solution system.

[Means for solving problems]

In other words, as an auxiliary means to promote the astringency removal effect of an ethyl alcohol-acetic acid aqueous solution, the first thing that can be considered is to accelerate the permeation rate of the aqueous solution into persimmons, and for this purpose, it is possible to add a homogeneous organic acid salt. This is probably due to the use of osmotic pressure.

Therefore, the inventors added many organic acid salts to an ethyl alcohol-acetic acid-based astringent removing aqueous solution, and investigated the astringency removing effect of persimmons. As a result, it was surprisingly found that aminocarboxylic acid salts, rather than simple salts such as sodium acetate, have an effective astringency removal promoting effect as co-catalysts in the aqueous solution system. The reason for this is thought to be that, in addition to the osmotic pressure effect of the carboxylate, reactive hydrogen atoms such as amino groups exert some kind of chemical effect on tannins, which are the main components of persimmon astringency. There are more than 30 types of amino acid salts that are useful here, depending on the field of protein, but from the viewpoint of being universal, easy to obtain, and having an effect on the human body,
Sodium glutamate (commercially available under the name "Ajinomoto") is suitable. In addition, a three-component aqueous solution obtained by adding acetaldehyde, which has long been speculated to have some relationship with astringency removal and has an extremely active hydrogen atom, in place of the aforementioned carboxylic acids. The astringency removal effect is very strong, and the astringency removal time can be further halved. This, in one aspect, supports the credibility of the present invention. However, the use of acetaldehyde
Considering the impact on the human body during work and concerns about residual aldehyde, this is not preferable. By the way, the amount of these amino acid salts added as a cocatalyst to the aqueous ethyl alcohol acetic acid solution of the previous application is 1 to 5 moles based on the amount of acetic acid.
A molar range is preferred. The reason is that if a small amount of 1 mol or less is added, the promoting effect will be halved.
Furthermore, even if a large amount of 5 mol or more is added, no significant increase in the promoting effect is observed, which is meaningless.

Furthermore, the astringency removal method using this three-component aqueous solution can be carried out in no different manner from the general astringency removal method using an ethyl alcohol aqueous solution. That is, the method involves soaking persimmon stems in this solution and then leaving the solution in a sealed container. The temperature at which the product is left at this time is surprisingly sensitive, and it is necessary to keep the room temperature within the range of 20°C to 25°C. If the temperature is below 20°C, hardly any promotion of the astringency removal effect will be observed, and if it is above 25°C, alcohol burning or persimmon softening will occur, which is undesirable.

The ethyl alcohol content of the astringent aqueous solution used in the present invention is preferably in the range of 20% to 40%. The reason for this is the same as in the case of a general ethyl alcohol aqueous solution for removing astringency (generally using shochu).

By performing astringency removal treatment using a three-component aqueous solution as described above, even persimmons that are difficult to remove astringency can be
It is possible to complete the astringency removal within 50 hours and obtain fresh astringent persimmons that have a strong sweetness, high hardness, and are completely free from alcohol roasting.

In addition, due to the characteristics of the three-component aqueous solution of the present invention, as a method for removing astringency, the solution is contained in a cloth-like sponge (for example, a plastic sponge cloth, etc.), and the stems of persimmons are placed in contact with it. If they are lined up like this and sealed, the astringency removal effect will further increase. Hereinafter, the usefulness of the present invention will be explained in detail with reference to Examples.

〔Example〕

In 1977, in Nagasaka Town, a highland area in the northwestern part of Yamanashi Prefecture.
On October 23rd, 120 kg of Koshu Maru Shibu persimmons were collected. Then, divide these into three parts each weighing 40 kg, and then divide them into three parts.
We compared the results by treating them with different types of astringency removal solutions. First of all
Firstly, 1000 c.c. of commercially available shochu, which is a 35% alcohol aqueous solution, was prepared as the astringent removal liquid, and secondly, an acetic acid-containing acetic acid-containing aqueous ethyl alcohol solution, which was the treatment liquid of the previous application, was prepared in the following manner. That is, make 750 c.c. of a 40% ethyl alcohol aqueous solution from absolute alcohol, add 250 c.c. of vinegar (acetic acid concentration 4.
(commercially available product) to obtain 1000 c.c. of ethyl alcohol-acetic acid aqueous solution. Third, a treatment liquid of the three-component aqueous solution of the present invention was prepared. That is, 50 g of commercially available Ajinomoto was further added as sodium glutamate to the treatment solution prepared in the same manner as in the second case, and the mixture was thoroughly stirred and dissolved. Two days after collection using these three types of treatment solutions.
On October 25th, persimmons weighing 40kg each were treated to remove astringency. First, a shallow plastic container was prepared, and a cloth-like urethane sponge impregnated with each treatment solution was placed on the bottom. The persimmons to be processed were then arranged in a row on top of it. Next, 10 stacks of these plastic containers were placed in an agricultural plastic bag, sealed, and stored in a pre-cooler for agricultural products to warm it up and maintain the temperature at 25°C.
After 36 hours, the persimmons treated with the three types of aqueous solutions were taken out, and the state of astringency removal was examined using cardboard that had been immersed in a 5% ferric chloride aqueous solution and dried. That is, this method utilizes a color reaction between ferric chloride impregnated into cardboard and water-soluble tannin.
As a result, the persimmons treated with the third aqueous solution according to the present invention did not show any color reaction to the test paper, indicating that the astringency removal was completed.
On the other hand, the second treatment solution was estimated to have removed astringency by approximately 70% based on the coloring of the test paper, and the first treatment solution was estimated to have removed astringency by approximately 30%. . Also,
Naturally, the firmness and freshness of the appearance of the Koshumaru persimmons, which were removed in such a short period of time, were not much different from those before the treatment. In addition, it is thought that similarly good results can be obtained with regard to the astringency of chestnuts.

Claims (1)

[Claims] 1. Acetic acid in the range of 5/100 to 1/1000 mol per 1 mol of ethyl alcohol, and 20% to 40% of the aminocarboxylic acid salt added to the acetic acid in the range of 1 mol to 5 mol. An aqueous solution for removing astringency from persimmons consisting of a 3-component aqueous solution with a range of 3.