Flavor Components in Sun-Dried Ray

마른 가오리의 풍미성분(風味成分)

To investigate the flavor components of sun-dried ray, Raja porasc, the contents of such as free amino acids, nucleotides and their related compounds, total creatinine, betaine, TMAO, fatty adds, and volatile compounds were analysed. The content of total free amino acids was 1773.3mg% on dry basis and the abundant amino acids were taurine, lysine, leucine, alanine, glycine, glutamic acid, proline, and valine in order and these amino acids accounted for 80% of total free amino acids in sun-dried ray. In the nucleotides and their related compounds, hypoxanthine was the most abundant. Ammonia-N was the most abundant, resulting 26.4% of extractive nitrogen which was 1965.6mg% and next free amino acid-N, total creatinine-N, and nucleotide-N in order. In the fatty acid composition of total lipid and neutral lipid, polyenoic acid was abundant holding 42.0%, 45.3% respectively. In phospholipid, the ratio of polyenoic acid and saturated fatty acid were similar to 39% respectively. The predominant fatty acids in total lipid, neutral lipid, and phospholipid were $C_{16:0},\;C_{22:6},\;C_{18:1},\;C_{18:0},\;and\;C_{20:4}$. In the volatile compounds, isocaproic acid, caproic acid, isobutyric acid, and butyric acid were the major portion of the 8 kinds of volatile fatty acids detected and 2-butanone, pentanal, and 2-methylpropanal were the major portion of the 8 kinds of volatile carbonyl compounds detected and also trimethylamine was the major portion of 2 kinds of volatile amines detected. It was presumed from the results that the reciprocal action of taste compounds such as free amino acids, nucleotides and their related compounds total creatinine, betaine, and TMAO and volatile compounds such as volatile carbonyl compounds, volatile fatty acids, volatile amines, and ammonia played an important role for the characteristics of flavor of sun-dried ray.

독특한 맛과 냄새성분 때문에 남도지방의 특산물로서 우리나라에서 즐겨 이용되고 있는 마른가오리의 풍미성분을 밝힐 목적으로 유리아미노산, 핵산관련물질, 총크레아티닌 및 베타인등의 정미성분과 지방산 그리고 냄새성분을 분석하였다. 마른가오리의 VBN 및 아미노질소는 각각 60.98mg% 및 95.82mg%였으며, 카르보닐값은 97.67meq/kg였고 pH는 7.18이었다. 유리아미노산함량은 1773.3mg%이었고 이중 taurine, lysine, leucine, alanine, glycine, glutamic acid, proline 및 valine 등이 전체의 80%정도를 차지하였다. 핵산관련물질중에서는 hypoxanthine의 함량이 가장 많았다. 전엑스분질소 함량은 1965.6mg% 이었으며 이중 암모니아질소가 519.0mg%로써 가장 많았고 다음으로 유리 아미노산질소, 총크레아티닌질소 및 핵산관련물질소 순이었다. 총지질에 대한 구성비는 중성지질이 92.5%, 인지질이 5.5%였으며 총지질과 중성지질에서는 폴리엔산이 각각 42.0%, 45.3%로써 가장 많은 량을 차지하였고 인지질에서는 포화산과 폴리엔산이 39% 정도로서 비슷한 양이었다. 총지질, 중성지질 및 인지질에서 양적으로 많은 지방산은 $C_{16:0},\;C_{22:6},\;C_{18:1},\;C_{18:0},\;C_{20:4}$ 순이었다. 또한 냄새성분중 휘발성지방산은 8종이 동정되었는데 이중 고린내 특유의 냄새성분을 나타내는 isocaproic acid, caproic acid, isobutyric acid 및 butyric acid 등이 많은 비율적 차지하였고 휘발성카르보닐화합물에서도 8종이 동정되어 이중 2-butanone, pentanal 및 2-methylpropanal등이 많은 비율을 차지하였다.