Analysis of the Free Amino Acids and Volatile-Flavor Compounds in the Commercial Brown-Rice Vinegar Prepared via Static Acetic-Acid Fermentation

This study was performed to evaluate the quality of the commercial brown-rice vinegars of South Korean and Japanese origins, which were prepared via static acetic-acid fermentation. The major free amino acids of Korean brown-rice vinegars were proline, glutamic acid and phenylalanine, while those of the Japanese were proline, valine, phenylalanine, lysine, ${\gamma}$-aminobutyric acid, alanine and isoleucine. The ${\gamma}$-aminobutyric acid (GABA) and total amino acids (3686.37~4212.27 mg%) contents were found to be significantly higher in the Japanese than in the Korean brown-rice vinegars. The key volatile compounds of the Korean brown-rice vinegars, analyzed with GC-MS, were acetic acid, benzaldehyde, phenethyl alcohol and phenethyl acetate while those of the Japanese brown-rice vinegars were acetic acid, ethyl acetate, ethyl alcohol, isoamyl acetate, phenethyl acetate and benzaldehyde. The volatile patterns of the Korean and Japanese commercial brown-rice vinegars were effectively distinguished from each other using an electronic nose, through which it was also elucidated that the volatiles profiles were similar among the Japanese vinegars but were different among the Korean vinegars.

시판 정치배양 현미식초의 유리아미노산 및 휘발성 향기성분 특성 분석

본 연구는 정치발효에 의한 국산 및 일본산 현미식초의 품질비교를 실시하였다. 국내산 현미식초의 주요 유리아미노산은 proline, glutamic acid와 phenylalanine인 반면, 일본산 현미식초는 proline, valine, phenylalanine, lysine, ${\gamma}$-aminobutyric acid, alanine과 isoleucine이었다. ${\gamma}$-aminobutyric acid (GABA)와 총아미노산 함량(3686.37~4212.27 mg%)은 국내산 정치배양 현미식초에 비해 일본산 정치배양 현미식초에서 유의적으로 높게 나타났다. GC-MS에 의한 주요 휘발성 향기성분 분석 결과, 식초의 주된 휘발성 향기성분인 acetic acid 이외에 국내에서 제조된 현미식초는 ethyl acetate, benzaldehyde, phenethyl alcohol와 phenethyl acetate 이었으나, 일본에서 제조된 현미식초는 ethyl acetate, phenethyl alcohol, ethyl alcohol, isoamyl acetate, phenethyl acetate와 benzaldehyde이었다. 전자코에 의한 향미패턴 분석결과, 국내 및 일본산 정치배양 현미식초 간의 향미패턴에 차이가 있음을 확인 할 수 있었으며 전자코에 의해 효과적인 구별이 가능하였다. 또한 일본산 현미식초는 제품 간 유사한 향기성분을 나타내었으나, 국산 현미식초는 제조사에 따라 서로 다른 패턴을 보였다.