Effect of Heating Time on Contents of Amino Acids and Related Compounds in the Muscle Extract of Snakehead

가열시간별 가물치육 엑스중의 아미노산 및 그 관련화합물의 변화

As a fundamental study of fresh water fish on a suitable cooking method and on flavor components from the view point of food science, changes in the free amino acid composition of the muscle extracts of snakehead (Channa argus) during heating in boiling water were investigated. The muscle extract of raw fish was featured a very high content of glycine, taurine, glutamic acid and histidine, and a large amount of urine was also determined in the extract; the former four components comprised about $53\%$ of the total free amino acids. The total extractable nitrogen was greatly increased with the heating time till 120 minutes of heating, while it gradually decreased thereafter. The apparently increased components on heating of 120 minutes were taurine, glycine, alanine, hydroxyproline, and ${\beta}$-aminoisobutyric acid, etc. including urea. After hydrolysis of the extracts, some of the amino acids were increased, the content of ethanolamine, lysine, 1-methyl histidine, phenylalanine, glutamic acid and taurine, etc. were apparently increased.

엑스성분에 대하여 비교적 알려진 것이 적은 담수어 중 가물치를 시료로 하여 가열 시간별로 육액스분중의 아미노산 및 그 관련화합물의 함량변화를 분석 검토하였다. 가물치의 생육중에는 glycine, taurine, glutamic acid, histidine이 특히 많은 함량을 보였고, 요소가 많이 함유되어 있는 것도 특기할 점이었다. 전술한 4 가지 성분이 전체아미노산 및 그 관련화합물중 약$53\%$를 차지하였다. 가열시간에 따른 전질소엑스분의 양적 변화를 측정한 결과, 대체로 가열 120분까지는 대폭 증가하였으나 그 이후부터는 감소하는 관계를 보였다. 120분간의 가열에서 특히 현저한 증가를 보인 성분은 요소를 비롯하여 taurine, glycine, alanine, hydroxyproline, ${\beta}$-aminoisobutyric acid 등이었다. 엑스분을 가수분해한 결과, 일부의 성분은 증가하였으며, ethanolamine, lysine, 1-methylhistidine, phenylalanine, glutamic acid, taurine 등은 현저한 증가경향을 보였다.