사과식초 제조를 위한 전단계로서 사과주스의 알코올발효 최적화를 실시하였다. 알코올발효 최적화를 위해 중심 합성계획이 사용되었으며, 이 때 독립변수로는 초기 당도(12, 14, 16, 18, 20 , ), 발효시간(48, 54, 60, 66, 72 hr, ), 발효온도(24, 26, 28, 30, , )로 설정하였으며, 종속변수로는 알코올함량, 환원당 함량, 당도, 산도를 살펴보았다. 발효조건에 따른 사과주스 알코올발효액의 알코올 함량은 3.4~6
The alcohol fermentation of apple juice was optimized as a preliminary study for the production of natural apple cider vinegar. To gain an optimal fermentation yield, a central composite design was used to investigate the effects of the independent variables [initial Brix (12/14/16/18/20, ), fermentation time(48/54/60/66/72h, ), and fermentation temperature(24/26/28/30/, )] on the dependent variables (alcohol content, reducing sugar, Brix, acidity). The alcohol content was 3.4-6.4%, the reducing sugar was 1.93-6.24%, and the Brix was . The alcohol content was mainly affected by the fermentation temperature and increased along with the fermentation time and temperature. The amount of the reducing sugar was significantly affected by the initial Brix and fermentation temperature. The optimal conditions for the alcohol content were found to be 15.22 initial Brix, 64.97 h fermentation time, and temperature.