Studies on the chages in Free Amono Acids of Yellow Corvenia(Pseudosciaena manchurice) during Gulbi processing

굴비제조중 유리아미노산의 변화에 관한 연구

Gulbi were processed by salting Yellow corvenia (Pseudosciaena manchurica) with in three ways: the dry salting method with bar salt, the dry salting method with purified salt or with the abdominal brine injection method with purified salt. The half of the sample was dried by the control system of temperature and humidity; the other part was dried by the natural condition. The moisture content of fresh Yellow corvenia muscle and eggs were 76.8%, and 68.2% while those of dried samples decreased to 57.7% and 45.3%, respectively. The total nitrogen content of fresh muscle and eggs were 11.0g% and 7.6g%, respectively (dry weight basis), which decreased slightly during salting and showed no significant changes during drying prosess. The protein nitrogen content of fresh muscle and eggs were 10.2g% and 7.5g%, which decreased during Gulbi processing. On the other hand, the nonprotein nitrogen content of both muscle and eggs increased. The content of free amino acids of fresh muscle and eggs were 508.8mg/100g and 1,110.6mg/100g, which increased to between 5.3 and 2.7 times, respectively after 25 days of drying. The composition patterns of free amino acids in muscle and eggs were similar to each other. The four amino acids - Ala, Glu, Lys and Leu - were most abundant in both fresh and dried samples. These amino acids are known as taste and flavour constituents.

굴비는 참조기(Yellow corvenia)를 정제건염법, 정제복장주입법, 천일건염법에 의해 염장한 후 절반씩 나누어 온도, 습도가 조절된 실내건조 조건과 자연건조 조건에서 건조하여 제조하였다. 이 과정에서 근육과 알의 유리아미노산 변화를 분석하여 다음과 같은 결과를 얻었다. 1. 수분함량은 근육의 경우 생시료에서 76.8%였으며 25일 건조했을때는 $53.2{\sim}62.2%$로 감소하였다. 알의 경우 생시료에서 68.2%였고, 25일 건조했을 때는 $42.3{\sim}48.4%$로 감소하였다. 2. 총 질소함량은 생시료 근육과 알에서 각각 평균 11.0%와 7.6%였는데 염장중 약간 감소하였으며 건조중에는 거의 변화가 없었다. 단백태질소 함량은 생시료 근육과 알에서 각각 10.2와 7.5%였는데 굴비제조중 감소한 반면 비단백태질소 합량은 증가하는 경향을 보였다. 3. 총유리아미노산 함량은 생시료 근육과 알에 각각 508.8mg/100g와 1,110.6mg/100g 함유되었는데 25일 건조후 근육은 5.3배, 알은 2.7배로 건조중 증가하였다. 유리아미노산 조성은 근육과 알이 유사하였으며 염장 및 건조중 뚜렷한 변화는 없었다. 건조기간중 정미성 아미노산으로 알려진 Ala, Glu, Lys, Leu이 많이 함유되어 있었다.