Abstract
Sarine scrap usually comprises about $40\%$ of the raw fish in processing. The purpose of this study is to establish the desirable methods for proteinaceous materials from the sardine scrap through autolysis or enzymatic digestion and to convert them into useful by-products such as sardine sauce. Sardine scrap was chopped and mixed with equal weight of water, and be hydrolyzed them by autolysis and/or by addition of commercial proteolytic enzyme and various concentrations of sodium chloride. The optimal conditions for hydrolysis of sardine scrap were revealed in temperature at $55^{\circ}C$ and 4 hours digestion with bromelain($0.4\%$) and commercial complex enzyme ($6.0\%$), and those conditions were also applicated in autolysis. The maximum hydrolyzing rate of protein and released amino nitrogen were $82.5\%,\;5.2\%$ through autolysis, $84.3\%,\;5.8\%$ by bromelain digestion and $92.5\%,\;5.9\%$ by complex enzyme, respectively. In the products prepared from sardine scrap through autolysis or bromelain digestion, hypoxanthine was dominant, as $17.4 {\mu}mole/g$, dry matter for autolysis and $16.0 {\mu}mole/g$, dry matter, for bromelain digestion among the nucleotidcs and their related compounds, respectively. The abundant free amino acids were leucine, glutamic acid, lysnie, valine and alanine. The contents of those amino acids were $51.3\%,\;48.3\%$ of the total free amino acids, respectively. And the contents of 5'-IMP and TMAO were negligible but total creatinine was developed in value from $9.2\%\;to\;10\%$ of total extracted nitrogen. The flavor of sardine sauce prepared from sardine scrap by autolysis or enzyme digestion were not inferior to that of traditional Korean soy sauce by sensory evaluation.
수산부산물을 효율적으로 이용하기 위한 방안의 하나로 정어리를 가공할 때 생기는 잔사를 원료로 하여금 자체에 존재하는 자가소화효소나 단백질분해효소로써 정어리간장제조를 시도하였다. 마쇄한 정어리잔사에 동량의 물을 첨가하여 가수분해시킬 때의 최적가수분해조건을 검토하고 아울러 제품의 정미성분을 분석하였다. 자가소화에 의한 경우와 bromelain이나 complex enzyme첨가구 모두 $55^{\circ}C$에서 최대활성을 나타내었고, 분해시간은 4시간이 가장 적합하였으며, 효소농도는 bromelaine의 경우 $0.4\%$, complex enzyme은 $6.0\%$가 가장 좋았다. 정어리잔사로써 만든 어간장의 단백질가수분해율 및 아미노질소는 각각 자가소화법인 경우 $82.5\%,\;5.2\%$, bromelain 첨가구는 $84.3\%,\;5.8\%$, complex enzyme 첨가구는 $92.5\%,\;5.9\%$이었다. 자가소화나 bromelain에 의해 제조된 정어리잔사로써 만든 정어리간장의 핵산관련물질은 hypoxanthine이 건물양 기준으로 각각 $17.4 {\mu}mole/g,\;16.0{\mu}mole/g$로서 가장 많았고, 유리아미노산 중 함량이 많은 것은 leucine, glutamic acid, lysine, valine 및 alanine으로서 전 유리아미노산에 대해 각각 51.3, $48.3\%$를 차지하였다. 그리고 5'-IMP와 TMAO는 엑스분질소에 대해 건물양 기준으로 각각 $0.2\%,\;0.4\%$로서 비교적 소량이었으나 총 creatinine은 엑스분질소에 대해 $9.2{\sim}10.0\%$로써 다소 높은 함량이었다. 관능검사결과 자가소화시킨 정어리잔사로써 만든 정어리간장은 효소첨가한 것이나 재래식 간장에 비해서 품질에 손색이 없었다. 정어리잔사는 단백질분해효소를 첨가하지 않은 자가소화만으로도 재래식 간장에 비해 손색없는 어간장을 제조할수 있다는 결론을 얻었다.