Contents of Free Amino Acids, and Nucleotides and Their Related Compounds of Dried Cod

대구 건제품의 핵산관련물질 및 유리아미노산 함량

In this experiment, the contents of free amino acids, and nucleotides and their related compounds of dried cod products were analysed by amino acid autoanalyzer and HPLC. Proline, histidine, lysine and alanine were dominant amino acids in raw extracts, having $65.4\%$ of total free amino acid contents, but the contents of aspartic acid, serine, isoleucine and phenylalanine were low, and methionine, tyrosine and arginine were detected in trace amount. In free amino acid composition of dried products, abundant amino acids were glycine, histidine, lysine, proline and alanine. Such amino acid as aspartic acid, methionine, tyrosine and phenylalanine were poor. In extracts of storage sample, most free amino acids were increased in both sun dried products and hot air dried products, and glycine, histidine, lysine, proline and alanine were abundant amino acid, such amino acid as methionine, tyrosine and phenylalanine were poor. In raw cod, inosine and IMP were dominant contents which 18.5, $10.0{\mu}mole/g$ on dry base, respectively, but the contents of ATP, ADP, hypoxanthine and AMP were detected less than $3.2{\mu}mole/g$. ATP and ADP were decreased while IMP, inosine and hypoxanthine were increased during drying and storage of cod.

저렴한 동물성 단백질의 급원인 냉동대구의 식품학적 기초자료를 얻기 위해 북양산 냉동대구육을 천일건조 및 열풍 건조시켜 1개월간 저장하면서 유리아미노산 및 핵산관련물질의 변화를 실험하여 다음과 같은 결과를 얻었다. 생시료에는 proline, histidine, lysine및 alanine의 함량이 가장 많았고, 천일건조시료, 천일건조 저장시료, 열풍건조시료 및 열풍건조 저장시료에는 glycine, histidine, lysine, proline 및 alanine의 함량이 가장 많았으며, 총유리아미노산의 함량은 저장중 현저히 증가하였다. 핵산관련물질의 함량은 생시료와 건조시료 및 저장시료 모두 inosine의 함량이 가장 많았으며, 다음으로 IMP의 함량이 많았다. 이상의 결과들로 미루어 볼 때 glycine, histidine, lysine, proline 및 alanine등의 유리아미노산과 핵산관련물질로서는 IMP등이 냉동대구를 원료로 한 대구 건제품의 맛에 중요할 구실을 할 것으로 추정된다.