JPH07227246A - Simultaneous production of violet pigment from sweet potato and foodstuff product - Google Patents

Abstract

PURPOSE:To extract a violet pigment of sweet potato of high heat and light resistance and obtain useful lees as a foodstuff by treating a kind of a modified species of violet sweet potato with aqueous alcohol under neutral to acidic conditions. CONSTITUTION:A modified species of violet sweet potato 'KYUUSHUU No. 113' is extracted with aqueous alcohol under neutral or acidic conditions. The alcohol is suitably methanol, ethanol or propanol, the concentration thereof is suitably 20 to 95%, particularly 30 to 80%. The pH lower than 4 is undesirable because the lees taste acidic or cause denaturation with the acid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a stable purple sweet potato pigment excellent in heat resistance and light resistance, and a purple sweet potato that eliminates industrial waste by using the lees after extraction of the pigment as a useful food material. The present invention relates to a method for simultaneously producing a pigment and a food material.

[0002]

2. Description of the Related Art Red natural pigments such as red cabbage, grapes and purple corn belong to anthocyanin pigments. Purple sweet potato is also a pigment raw material containing a similar anthocyanin pigment. Recently, this dye is more excellent in heat resistance and light resistance than other anthocyanin dyes, so that it is expected to be used in foods, and various studies have been made on its manufacturing method. For example, a method for producing a purple sweet potato pigment by extracting raw or steamed purple sweet potato with water or hydroalcohol under acidic conditions and adsorbing and concentrating the extract (JP-A-62-
297363, Japanese Patent Laid-Open No. 62-297364), the raw material is treated at 10 ° C. or lower, or a frozen and pulverized raw material is used to extract the enzyme activity suppressed with water or hydrous alcohol, A method for producing a purple sweet potato pigment by adsorbing and concentrating the extract, etc. (JP-A-4-103669) has been proposed.

However, the techniques studied so far are limited to purple sweet potatoes as a raw material such as Yamakawa purple, Tanegashima native, Ei purple, Chiran purple, Kiiri purple, Nakamurasaki, etc. However, the dye was difficult to extract, and there was a limit to industrial use in terms of extraction efficiency and quality of the extracted dye. In addition, it is a well-known fact to those skilled in the art that anthocyanin pigments are discolored by the oxidase contained in the raw material, but in order to avoid this, it is easy to extract the pigment from the ground material while cooling the raw material. It has been considered and has been implemented and studied by each company for a long time. However, this method complicates the manufacturing process and causes local heat generation during pulverization, so that the raw material is, for example, liquid nitrogen or a freezer, and is used at −10 ° C. or −3.
It was necessary to cool to 0 ° C. and finely pulverize, and there was a limit to industrial use.

Anthocyanin dyes are
Moreover, the extraction method under strongly acidic conditions of pH 4 or less has been conventionally performed as preferable, but when the lees after the extraction of the pigment is used as a food material, the taste of the acid and the modification with the acid affect the taste and texture. It had a great influence, which was one of the obstacles that prevented the meal from being used as a food material. Furthermore, until now, the lees after the extraction of the pigment were difficult to extract the pigment, and a purple streak with a faint color was seen, and it was not suitable as a food material in appearance, and the fiber was strong and even if it was cooked normally It did not become a high-starch food material such as sweet potato, was not used elsewhere, and was directly disposed of as industrial waste.

[0005]

DISCLOSURE OF THE INVENTION The present invention addresses the problem by improving the purple sweet potato itself, which is a raw material, and provides a production method capable of efficiently producing a pigment and at the same time making the lees after extraction a useful food material. With the goal.

[0006]

[Means for Solving the Problems] The present inventors can efficiently obtain a large amount of high-quality pigments from purple sweet potato and make the extracted lees a useful food material without converting them into industrial waste. As a result of intensive research, the present invention has been achieved. That is, the present inventors first developed an improved cultivar "Kyushu 113" bred with Satsuma Hikari as a father and an improved cultivar "Kyushu 109" with Chiran purple as a mother and Yamakawa purple as a father. After examining the extraction method of the pigment suitable for the variety, this purple sweet potato was cut into chips, etc. if necessary, soaked in neutral to acidic hydrous alcohol, or with or without cutting the raw material. It was found that the raw material may be crushed or stirred with a mixer or the like in the presence of an acidic to acidic hydrous alcohol. It was found that the raw material may be with or without the skin on it, and that the raw material need not be cooled and may be treated at room temperature. Of course, the raw material may be cooled and frozen for processing, or the raw material may be processed in an environment in which the gas is replaced with an inert gas such as nitrogen gas. Sufficient quality by simply immersing the cut into a neutral to acidic hydrous alcohol at room temperature and / or crushing or stirring the raw material in the presence of a neutral to acidic hydrous alcohol at room temperature. It was found that a high content of dye liquor was obtained.

By this method, almost all of the pigment in the raw material can be extracted, and when the liquid and the solid are separated by a conventional method such as filtration or centrifugation, a purple sweet potato pigment liquid is obtained.
It is also possible to obtain a white extract cake with almost no pigment. By adjusting the extraction conditions, the color of the extracted lees can be freely adjusted from white to dark purple, that is, white, light red, red, bright red, dark red, light purple, purple, fresh purple, dark purple, etc. It is possible to make sweet potatoes and potatoes, or even imitate red bean paste, but this is a faint purple paste obtained when using conventional purple sweet potatoes as a raw material, There is a big difference visually and in texture from the above-mentioned texture, and the result shows that "Kyushu 113" is superior as a food material. However, in terms of taste, "Kyushu 113" had bitterness, which was a big problem, but the one treated with the production method according to the present invention has the bitterness completely removed, and can be used as a food material for the first time. Became.

[0008] Extract lees obtained by sufficiently extracting pigments are almost the same as those of ordinary sweet potatoes, and their tissues are not strong in fibers and rich in starch, and not only the appearance but also the texture are similar to those of ordinary commercially available sweet potatoes. There was no change. However, when water containing no alcohol or hydrous alcohol having an alcohol concentration of less than 20% is used for extracting the pigment, the extraction rate of the pigment is low, the stability of the extracted pigment is low, and the extracted lees are textured. It becomes dull and unfavorable, and in terms of taste, the bitterness remains unfavorably like the raw material in which no pigment is extracted at all. The hydrous alcohol used both for extracting the pigment and for using the extracted meal as a food material is preferably an alcohol having 3 or less carbon atoms, that is, methanol, ethanol or propanol,
The alcohol concentration is preferably 20 to 95%, more preferably 30 to 80%. The liquidity may be neutral to acidic, but for the use of the extracted meal as a food material, it is strongly acidic, that is, under the conditions of pH 4 or less, the taste of the acid and the modification by the acid greatly affect the taste and texture. Not good.

The obtained dye solution may be used as it is or may be purified by a column or the like. Further, as it is or after being purified, it may be concentrated to obtain a concentrated pigment, or may be powdered by a spray drying method or the like. Heat treatment such as batch sterilization or plate sterilization may be performed in order to prevent discoloration of the dye solution and growth of bacteria. The condition in this case is 80 for batch sterilization.
30-100 minutes at -100 ° C is sufficient, and 20 seconds-30 minutes at 100-120 ° C is sufficient for plate sterilization.

The obtained extracted meal can be used as it is, or can be steamed and made into a paste by a standard method, and can be a useful food material as a dried product or a powdered product by a drum dryer or the like. It is also useful as a feed. If necessary, sugars, seasonings and the like may be added to the extracted meal, and the dried product and the powdered product may or may not undergo the cooking step.

[0011]

The present invention will be described in more detail with reference to the following examples. Example 1 Purple sweet potato improved variety "Kyushu 113" 1 kg was cut into 1 to 5 mm dice with a cutting machine, and immediately 3 L of 80 was cut.
% Ethanol solution, stirred at room temperature for 3 hours and then filtered to obtain a purple sweet potato extract dye solution. This liquid was used as Diaion HP-21 (adsorption resin manufactured by Mitsubishi Kasei Co., Ltd.) 100
After adsorbing to 58 ml of water and washing with water, 150 ml of 58% ethanol was used to elute the adsorbed dye. Concentrate the obtained dye solution to 50 g with a vacuum concentrator,
15 g of 5% by volume ethanol, 1 g of citric acid and 34 g of water were added to obtain 100 g of purple sweet potato dye solution. In addition, the extracted lees were steamed in a steamer, added with 150 g of granulated sugar and 3 g of salt, kneaded, and further lined to paste 1.1.
I got kg. Experimental Example 1 The pigment liquid obtained in Example 1 exhibited a vivid red-purple color when added to a carbonated beverage, and did not cause any change in color tone or insoluble matter even when left at room temperature for 1 month. Moreover, when the paste obtained in Example 1 was wrapped in rice cake and tasted, it was a delicious potato paste Daifuku rice cake. Example 2 5 mm of 1 kg of improved purple sweet potato variety "Kyushu 113"
Cut into sticks with a length of 15 cm or less at corners, put in a basket of wire mesh, put a lid on it, and immediately put it in 3 L of 30% methanol solution and shake the basket at room temperature for 5 hours to obtain a purple sweet potato extract dye solution. . This liquid was adsorbed on 100 ml of Diaion HP-21 (adsorption resin manufactured by Mitsubishi Kasei Kogyo Co., Ltd.), washed with water, and then the adsorbed dye was eluted with 150 ml of 58% ethanol. The obtained dye solution was used as a membrane having a molecular weight cut off of 100,000 (manufactured by Nitto Electric Industry Co., Ltd.
The solution was passed through an ultrafiltration membrane NTU-35100) and then concentrated to give 9
15 g of 5% ethanol, 1 g of citric acid, and 34 g of water were added to obtain 100 g of purple sweet potato dye solution. Also, the extracted lees remaining in the basket are fried together with the basket in an oil at 100 to 150 ° C., 20 g of starch syrup, 50 g of granulated sugar and 10 g of water are kneaded and boiled, dried with a candy-shaped syrup, and dried to about 5
Obtained 00g of potato kempi. Experimental Example 2 The pigment liquid obtained in Example 2 was added to the vitamin C beverage having the formulation shown in Table 1 and stored in a constant temperature bath at 50 ° C for 10 days. As a result, it was found that this dye exhibits extremely good stability. The state of the change over time at this time is shown in Table 2 as the residual rate when the absorbance at the maximum absorption wavelength at the start is 100%.
Shown in. Further, when the potato kempi obtained in Example 2 was sampled, it had no difference in texture and taste from those on the market.

[0012]

[Table 1]

[0013]

[Table 2]

Experimental Example 3 In the same manner as in Example 1, instead of "Kyushu 113", a dye solution was prepared using the conventional varieties of purple sweet potatoes, such as purple Yamakawa, Tanegashima, Chiran purple, and Nakamurasaki. The extracted meal was made into a paste and compared with the paste obtained in Example 1. As a result, the value of the absorbance at the maximum absorption wavelength of the 10% concentration solution of the dye solution (hereinafter referred to as color value) is as shown in Table 3, and "Kyushu 113" has a 4-5 times higher dye yield than conventional varieties. Moreover, it was found that the pigment was easily extracted. Moreover, as shown in Table 4, the paste was not preferable because it had a poor texture and a purple appearance with a faint appearance.

In the same manner as in Example 1, instead of stirring in an 80% ethanol solution for 3 hours, the mixture was stirred for 25 minutes to obtain a paste from the extracted meal (hereinafter referred to as the paste of Experimental Example 3). Compared with the paste, the appearance was much deeper and more vivid even though it had the same purple color as the paste of the conventional type purple sweet potato, and the texture was the same as that of a regular commercially available sweet potato as Hokuhoku. In terms of taste, neither the paste of Example 1 nor the paste of Experimental Example 3 felt bitterness at all, which was preferable as a food. Furthermore, 1 kg of "Kyushu 113" was steamed in a steamer in the same manner as in Example 1 without any extraction treatment of the pigment, and granulated sugar 150 was added.
g and 3 g of salt were added and kneaded, and the mixture was lined to prepare a paste (hereinafter referred to as an untreated paste), and its taste was compared with others. The untreated paste has a strong bitterness, is not very usable as a raw material for food, and its color is not vivid and turbid, which is clearly inferior to the pastes of Example 1 and Experimental Example 3. It was The results are shown in Table 4.

[0016]

[Table 3]

[0017]

[Table 4]

[0018]

EFFECTS OF THE INVENTION According to the present invention, a high dye yield of 4 to 5 times or more can be obtained by a simple process as compared with the case of using the conventional purple sweet potato, and the lees after extraction are not treated as industrial waste. Now it can be used as a useful food ingredient. Moreover, the color of the food material thus obtained can be freely adjusted from white to deep purple, and it has become possible to be applied to various uses.

Claims (3)

[Claims] [Claim 1] Improved variety of purple sweet potato "Kyushu 113"
A process for producing a purple sweet potato pigment, which comprises treating the product with a hydrous alcohol under neutral to acidic conditions. 2. An improved variety of purple sweet potato "Kyushu 113".
Treated with hydroalcoholic under neutral to acidic conditions,
A method for simultaneously producing a purple sweet potato pigment and a food material, characterized in that the lees after the pigment extraction are made into a paste and / or a powder. 3. The alcohol concentration of hydrous alcohol is 20 to.
It is 95%, The manufacturing method of Claim 1 or 2.