원문정보
Comparison of Temperature Effects on Brewing of Makgeolli Using Uncooked Germinated Black Rice
초록
영어
In this study we investigated the effect of temperature on the two-stage fermentation of Makgeolli using uncooked germinated black rice. The fermentation processes were conducted at 15℃ for three weeks and 25℃ for 7 days. The pH of Makgeolli at 25℃ increased from pH3.0 to pH 4.2, which was consistent with that at 15℃. In contrast total acidity of Makgeolli at 15℃ was about half of that at 25℃ (0.36% and 0.59%, respectively). By the 7 days-fermentation at 25℃, 11% of alcohol was produced, whereas three weeks were required for the same alcohol production at 15℃. In the case of sugar contents, the amounts of total glucose-equivalent reducing sugars and glucose increased at the end of the fermentation at 25℃ up to 2.25 mg/mL and 3.4 mM, respectively, whereas those at 15℃ were maintained at very low levels (0.18 mg/mL and 0.1 mM, respectively). Such limited supplement of sugars at 15℃ seemed to affect metabolism of yeast, resulting in different composition of organic acid. At 25℃, citric acid that was 73.4 ppm at the initial fermentation was consumed completely, whereas 20 ppm of citiric acid was remained at 15℃. In addition, acetic acid and lactic acid in Makgealli at 15℃ were 53% and 14% of those at 25℃.
목차
1. 서론
2. 재료 및 방법
2.1. 실험재료
2.2. 막걸리 제조
2.3. pH 및 총산 함량 측정
2.4. 알코올 함량분석
2.5. 환원당 정량
2.6. 포도당 정량
2.7. 유기산 분석
3. 결과 및 고찰
3.1. 발효 설계
3.2. 저온과 상온발효에서 막걸리 내 총산도 및 pH 변화
3.3. 저온과 상온발효에서 막걸리 내 알코올 함량 변화
3.4. 저온과 상온발효에서 막걸리 내 환원당 및 포도당 분석
3.5. 저온과 상온발효에서 막걸리 내 유기산 함량 변화
4. 결론
감사
References