JPH0317B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for preventing discoloration of chestnuts, root vegetables, and root vegetables. In general, root vegetables such as chestnuts, potatoes, and burdock, and root vegetables such as lotus root contain polyphenols such as leucocyanidin and chlorogenic acid, and tyrosine, and these also contain the enzymes polyphenol oxidase and tyrosinase. Due to the action of oxidation during storage or cooking, it causes discoloration of the above-mentioned side dishes. Conventionally, sulfites, ascorbic acid, etc. have been used to prevent this discoloration, but they are still far from satisfactory. For example, sulfites were once frequently used because of their remarkable effects, but now, There are regulations on its use under the Food Sanitation Law, and strict restrictions are also placed on the amount of residue. On the other hand, the discoloration prevention effect of ascorbic acid is weak;
Moreover, the effect does not last very long. In view of these circumstances, the present inventors have conducted various studies and found that γ-
It has been discovered that oryzanol has an excellent anti-discoloration effect. That is, the present invention is a method for preventing discoloration of chestnuts, root vegetables, or root vegetables, which comprises immersing the edible parts of chestnuts, root vegetables, or root vegetables in a solution containing γ-oryzanol. Chestnuts, root vegetables, or root vegetables used in the present invention are not particularly limited, and polyphenols, tyrosine, etc. contained in the vegetables are oxidized by the action of polyphenol oxidase, tyrosinase, etc., and this causes discoloration. The method of the present invention can be applied to any type of material. chestnuts,
Examples of root vegetables or root vegetables include chestnuts, root vegetables such as potato, burdock, taro, sweet potato, or carrot, and root vegetables such as lotus root and Japanese ginger. It is preferable to peel the chestnuts, root vegetables, or root vegetables and use the edible parts thereof, and furthermore, they can be used by cutting them into appropriate shapes. Commercially available γ-oryzanol can be suitably used, and the concentration in the γ-oryzanol-containing liquid is preferably about 0.003 to 5%, particularly about 0.05%. The γ-oryzanol-containing liquid may be a solution, suspension, emulsion, or the like. In carrying out the method of the present invention, a γ-oryzanol-containing liquid is first prepared, but when the containing liquid is used as a solution, it may be a hydrous alkanol solution, and particularly preferably a hydrous ethanol solution. When used as a suspension or emulsion, γ-oryzanol can be dissolved in a small amount of ethanol or the like and dispersed in water to form a suspension or emulsion. If a surfactant is used in combination, a more stable emulsion can be prepared. As the surfactant, for example, propylene glycol fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, etc. can be used, and these surfactants have a concentration of about 0.5 to 1.0 w/w.
It is appropriate to add it to water to give a concentration of %.
Then, the edible parts of chestnuts, root vegetables, or root vegetables are soaked in this. The immersion treatment may be carried out for about 0.5 to 12 hours, and the immersion treatment can be carried out at any temperature within the range of about 10 to 70°C, but it is preferably carried out at room temperature. The soaked edible portion is then washed with water and drained to obtain chestnuts, root vegetables, or root vegetables that have been treated to prevent discoloration. Furthermore, in the present invention, L-cysteine or a salt thereof can be used together with γ-oryzanol in the immersion liquid, thereby further enhancing the browning prevention effect of γ-oryzanol. L-cysteine or its salt is chestnut,
It may be added to the γ-oryzanol-containing solution before the soaking treatment of root vegetables and root vegetables, and as the L-cysteine or its salt, in addition to free L-cysteine, for example, hydrochloride etc. can be used. can. It is appropriate to use L-cysteine or a salt thereof in an amount of about 1 to 10 times, particularly about 3 times, the amount of γ-oryzanol. According to the method of the present invention as described above, the effect of preventing discoloration can be obtained by an extremely simple method such as immersion in a solution containing γ-oryzanol, and the γ-oryzanol can be removed by simply washing with water. Moreover, γ-oryzanol is harmless to the human body and has excellent safety from the viewpoint of food hygiene. Hereinafter, the present invention will be explained in more detail using experimental examples and examples. Example 1 Peel the skin of Shikoku chestnuts and remove 2 to 3 edible parts.
After soaking in water for an hour, drain the water. Next, 1 kg of this was boiled for 40 minutes at 92 to 94°C in γ-oryzanol-containing liquid 1 shown in Table 1 below. Next, wash and drain the chestnuts with cold water, bottle 250g each, and pour about 200g of sugar solution with a sugar content of 65 degrees. Close the bottle and heat at 90℃ for 35 minutes to sterilize. The jarred candied chestnuts thus obtained were stored at room temperature under diffused light, and changes in the appearance of the chestnuts in the jar were observed. The same procedure was carried out except that water and an ascorbic acid aqueous solution were used as controls. The results are shown in Table 1 below.

【table】

[Table] Example 2 After washing and peeling burdock, cut into appropriate sizes. 500 g of them were immersed in the γ-oryzanol-containing solution shown in Table 2 for 12 hours. The samples were then taken out, washed with water, drained, placed in a polyethylene bag, and stored indoors under diffused light at room temperature (18°C), and changes in appearance were observed. As a control, water and an ascorbic acid aqueous solution were used and the same procedure as above was carried out. The results are shown in Table 2 below.

[Table] Example 3 After peeling potatoes, they were sliced and immersed in a γ-oryzanol-containing solution shown in Table 3 below for 5 minutes. The sample was then taken out, washed with water, drained, placed in a polyethylene bag, and stored in a refrigerator (5°C), and changes in appearance of color tone were measured using a Hunter color difference meter. The same procedure as above was carried out using water as a control. The results are shown in Tables 4 to 6 below. In addition, when L is 50 or less, a is 9 or more, and b is 20 or more, as measured by a Hunter colorimeter, it indicates that there is considerable browning.

【table】

【table】

【table】

[Table] This shows that the browning is more advanced.

[Table] shows green color.

【represent.

Claims (1)

[Scope of Claims] 1. A method for preventing discoloration of chestnuts, root vegetables, or root vegetables, characterized by immersing the edible parts of chestnuts, root vegetables, or root vegetables in a γ-oryzanol-containing solution.2. It is burdock or burdock,
Method 3 according to claim 1, wherein the root vegetable is lotus root. The method according to claim 1 or 2, which uses a liquid containing γ-oryzanol and L-cysteine or a salt thereof.