魚類 및 새우 低溫貯藏中의 鮮度 變化 = Freshness of Fish and Shrimp during Cold Storage

국문 초록 (Abstract)

Saito等(1959)이 提案한 K-値에 依한 鮮度 判定法이 우리나라에서 生産되는 魚類나 甲殼類의 鮮度를 判定하는데 適用할 수 있는가를 檢討하기 위한 資料를 얻기 위하여 Kobayashi and Uchiyama(1970)의 K-値 迅速定量法으로 우선 底棲魚種이며 白色肉이 많은 붕장어, 表層회游魚이고 活動性이 强한 학꽁치 및 海底에 묻혀 사는 보리새우를 試料로 하여 氷藏및 凍結貯藏中의 K-値의 變化를 實驗하여 揮發性鹽基窒素量, 總菌數, pH 및 官能檢査 結果와 比較하였다.
살아 있는 붕장어와 보리새우를 卽殺하여 氷藏하였을 때 貯藏 中의 K-値는 貯藏期間에 따라 거의 직선적으로 增加하였다. 官能檢査 結果와 比較하여 보면 氷藏 8日만에 腐敗初期에 도달하였으며, 이 때 붕장어의 K-値는 26%, 보리 새우의 K-値는 23%였다.
한편 鮮度 좋은 학꽁치도 氷藏 中 K-値가 急激히 增加하였으며 腐敗初期라고 보아 지는 氷藏 7日째의 K-値는 43%였다.
K-値 揮發性鹽基窒素量, 總菌數, pH 및 官能檢査 結果를 比較하여 볼 때 K-値는 生鮮의 品質을 評價하는데 있어 有效한 判定方法 中의 하나라고 볼 수 있다.

다국어 초록 (Multilingual Abstract)

It is so far suggested from the results of investigation on the changes in nucleotides during the storage of fish and shellfish that ATP rapidly breaks down and forms such derivatives as adenylic acid, inosinic acid, inosine and hypoxanthine, and ribose, mainly in the early stage of storage.
Therefore K value representing the ratio of optical densities of inosine and hypoxanthine fraction and total nucleotide fraction at 250 nm may be useful as an index to measure the freshness of the fishes in prior to bacterial deterioration.
In this paper, the correlation between K value and freshness was discussed to elucidate whether K value is an useful index of freshness.
The freshness variations of conger eel, half beak and oriental brown shrimp during icing and cold storage were determined by means of volatile basic nitrogen, pH, total bacterial count, and organoleptic test.
The results showed that the K value of the three smaples were rapidly and linearly increased during iced storage being changed 26% for the conger eel, 23% for the oriental brown shrimp and 43% for the half beak respectively, while that was maintained almost consistently during three months cold storage at -20℃.
As a conclusion it is noted that the K value could be useful as an index to measure the freshness of fish muscle preserved with ice.