유기농 영귤(Citrus sudachi)의 이화학적 특성 및 소스 제조적성

Abstract

Citrus sudachi is a small, round, green citrus fruit that is relatively unknown outside Jeju, where it is used alongside another citrus fruit, the yuzu and lemon. It is considered to have a zestier flavor and aroma than lemons or yuzu. For these reasons, it is the very useful citrus fruit as ingredients including sauce or additives. In this study was performed to investigate physiochemical and processing properties of Citrus sudachi cultivated by organic farming that excludes the use of synthetic fertilizers and pesticides, and then to make sauces with sudachi juice. The results of the present study were as follows;

1) The size and weight of sudachi was increased in accordance with its ripeness. It was almost ripe in the mid-september to the beginning of October. When the sudachi was ripe, the extracted juice rate was on the rise and the thickness of its peel was reduced, sugar level and pH were on the increase; however, total acidity and vitamin C were on the decline, and its special fragrance disappeared. Its green color was turned into yellow in the end of October. The fragrance was reduced by half. Citric acid accounted for 5.5 %, it meaned, 92 % out of total organic acid (6.08 %). There were 17 kinds of amino acids.

2) In oder to examine the septic rate of sudachi were divided three types of storage methods of the fruits, a normal temperature storage, a low temperature storage (6±1℃) and a low temperature PF (polyethylen film) packing storage. First, the septic rate in the normal temperature storage reached up to 55 % on the third day after the storage. The sudachi lost its productive value on the fifth day. Second, when it came to a low temperature storage, packing the sudachi in the PF had the low septic rate. Accordingly, it could be possible to store the sudachi for 5 days after harvested. In terms of a sudachi juice-extracting method, it was selected the Cursh-screw press type, because the extracted juice rate went up by 65 %, flavonoid, a biologically active substance of the peel, was fully activated. However, if refined elements of the peel are excessively mixed, the smell of acidification could occur when it was stored and distributed.

3) An experiment was conducted on a sauce group with extracted juice instead of vinegar when making sauce with soy sauce, hot pepper paste, salted anchovies and pickled damsel fish. By doing this, it was examined if both had different tastes. The result showed they had significant difference. As the result of acceptance on the sauce added with extracted juice, it was found that it was superior to the sauce made from vinegar. They were kept in cold storage for 60 days; however, there were no difference. If the sauce with extracted juice is kept in a refrigerator, its quality can remain stabilized at least within two months.

In conclusion, considering the aroma of citrus sudachi and acid content, it is desirable to harvest them in mid-September. Moreover, the oranges classified as damaged fruit of its peel has to be processed within two days if they are kept in a normal temperature storage. In order to put useful substances of its rind into sudachi juice, it is necessary to have the Cursh-screw press type, and include procedures of separation, sterilization, homogenization and air eradication to make processed products. In addition, it is possible to use processed goods made from the extracted juice of citrus sudachi as all kinds of seasonings. Therefore, imported lemons or limes can be replaced with Citrus sudachi.