Abstract
In order to elucidate the taste compounds of Korean catfish, Parasilurus asotus, free amino acids, nucleotides and their related compounds, organic bases, sugars, organic acids and minerals in the extracts of Korean catfish were analyzed, and then evaluated by sensory test of synthetic extract prepared on the basis of the analytical data. Taste panel assessments of synthetic extracts prepared with each extractive component omitted were carried out by a triangle difference test, and changes in taste profile were assessed. In free amino acid composition, glycine was dominant occupying $25\%$ of total free amino acids. The other abundant free amino acids were lysine, taurine and alanine. Judging from the result of analysis of nucleotides, IMP was dominant showing about $70\%$ of total nucleotides while ATP, ADP, AMP, inosine and hypoxanthine were low in content. Among organic bases, total creatinine was abundant and its nitrogen content occupied more than $50\%$ of the total extractive nitrogen. The amount of betaine was 18mg/100g and trace amount of trimethylamine and trimethylamine oxide were detected. The main organic acids were succinic, butyric, propionic and valeric acid. On the other hand, oxalic, fumaric, maleic, tartaric and citric acids were analyzed in trace. As for the sugars, glucose was found to be the most abundant monosaccharide. Extremely small amounts of fructoae, inositol were also detected and ribose and arabinose were trace in content. $K^+,\;Na^+,\;PO_{4}^{3-}$ and $Cl^-$ were found to be the major ions and small amount of $Ca^{2+}$ were defected. The synthetic extract, prepared with about 40 pure chemicals based on the analytical data satisfactorily revealed the natural taste of the original extract except slight difference in meaty taste and mildness. From the results of omission test the major components which contribute to produce the taste were serine, IMP, succinic acid and $PO_{4}^{3-}$.
우리 나라 중요 담수어의 정미성분을 밝힐 목적으로 전보에 이어 메기배육중의 유리아미노산, 핵산관련물질, 유기염기, 당류, 유기산 및 무기질을 분석하였다. 또한 이 분석치를 기초로 하여 표준 시약을 가지고 합성엑스분을 조제하여 천연엑스분과 맛을 비교하였으며, omission test를 실시하여 각 성분들이 맛에 미치는 영향을 조사하였다. 유리아미노산의 함량은 glycine이 가장 맞아 전체 유리아미노산의 $25\%$를 차지하였고, 다음으로 alanine, lysine, taurine등이 많았다. 핵산관련물질은 IMP 함량이 98.9mg/100g으로서 가장 많았으며, 그 외 성분은 비교적 함량이 적었다. 유기염기는 creatinine이 351.7mg/100g으로서 가장 많았고 betaine은 18.0mg/100g이었으며 TMA 및 TMAO는 1.4mg/100g 이하로서 극미량이었다. 유기산의 경우는 숙신산, 브티르산, 프로피온산 등이 함량이 많았고 옥살산, 푸마르산, 말레산, 타르타르산 및 시트르산은 흔적량에 불과하였다. 당류의 함량은 포도당이 5.1mg/100g으로서 가장 많았으며, ribose, arabinose, fructose및 inositol은 약 1mg/100g으로서 미량이었다. 무기염류의 함량은 $K^+$ 및 $PO_{4}^{3-}$이 각각 210.0mg/100g, 305.8mg/100g으로서 월등히 많았고 다른 무기염류는 38.0mg/100g이하였다. 관능검사 결과로 본 매기의 주된 정미성분은 serine, alanine, IMP, 숙신산 및 $PO_{4}^{3-}$였다.