Bacillus subtilis p01 균주를 사용한 청국장 제조 시 유카 추출물의 첨가가 청국장의 숙성중 품질 특성에 미치는 영향을 검토하고자 청국장 숙성 과정중의 아미노태 질소, 암모니아태 질소, amylase 활성, pretense 활성, 유기산 성분의 변화, 향기성분의 변화를 조사하였다. 청국장의 숙성 중 아미노태질소 함량은 유카 첨가구에서 증가 하였으며, 암모니아태 질소는 유카 첨가구에서 감소하였다. Amylase 활성은 유카 첨가구들이 대조구와 비교 시 높게 나타났으며, 유카 추출물을 0.5 mg/g 첨가 시 효소활성이 가장 높았다. Pretense 활성 역시 유카 추출물 첨가구가 무첨가구보다 다소 높게 나타났다. 유기산은 유카 첨가구들에서 citric acid, acetic acid, malic acid가 검출되었고, 2,5-Dimethylpyrazine이 증가하였고, 불쾌취로 작용되는 cis-3-hexane이 숙성 기간 중 감소함을 보였다.
This study was carried out to investigate the effect of yucca extract on the quality characteristics of Chungkookjang using Bacillus subtilis p01. The changes in the contents of amino-type N, ammonia type N, volatile compounds and organic acids, and those in the activities of ${alpha}-amylase$ and protease were also determined during aging of Chungkookjang. The amount of amino-type N increased gradually with time for aging. The content of amino-type N was slightly higher in Chungkookjang fermented by adding yucca extract than in the control without yucca extract. The content of ammonia-type N was slightly lower in Chungkookjang with yucca extract than in the control without yucca extract. The activities of amylase and protease were higher in Chungkookjang with yucca extract than in the control and the highest in Chungkookjang containing 0.5 mg/g of yucca extract. Organic acid contents in Chungkookjang was the highest at the initial period of fermentation. The contents of organic acids in Chungkookjang with yucca extract was higher than that in control for 48 hr of aging. The amounts of 2,5-dimethylpyrazine were increased by addition of yucca extract, while those of cis-3-hexanol were decreased.
