Changes in Compositions of Liquor Fractions Distilled from Samil-ju with Various Distillation Conditions

증류조건에 따른 삼일주 증류액의 성분변화

Samil-ju, the traditional Korean rice wine was brewed and distilled using different columns (unpacked and packed) at different pressure (760, 460, 260 mmHg). Fractions of distillate were collected and analyzed. The sample wine, Samil-ju showed the following compositions; ethanol 14%, total acidity 16.2 g/100 ml, reducing sugar 7.9 mg/ml, total sugar 8.4 mg/ml, acetaldehyde 6 ppm, fusel oil acetaldehyde and ethyl acetate 6 ppm. As distillation proceeds, contents of ethanol, methanol, fusel oil, acetaldehyde and ethyl acetate were decreased but total acidity was increased. Generally at reduced pressure, all the constituents but total acidity showed more decrease than those at atmospheric pressure. In the 1st, 2nd and 3rd fractions of the distillate, ethanol contents were maintained at about 70% but those contents decreased abruptly to below 50% from the 5th fraction. Sixteen sensory characteristics were identified as quality factors of distillate. Among them, four characteristics were identified as aroma properties, seven as tastes and five as aftertastes. Nuruk and cooling flavor were considered as important factors which affect greatly the sensory quality of distillate. Among various fractions, the 2nd, 3rd and 4th fractions obtained from unpacked column at 260 mmHg showed the highest score in the overall quality. The compositions of these fractions were ranged as follows; methanol $24{\sim}36\;ppm$, total acidity $0.21{\sim}0.29\;g/100\;ml$, fusel oil 657-1340 ppm, acetaldehyde $12{\sim}41\;ppm$, and ethylacetate $22{\sim}311\;ppm$, respectively.

쌀을 원료로 한 우리나라 전통주인 삼일주를 제조하고 이를 증류한 증류주의 성분변화를 압력, 환류비 및 충전물의 유무에 따라 분획별로 분석하여 다음과 같은 결과를 얻었다. 삼일주의 성분중 에탄올 함량은 14%, 총산 16.2g/100 ml, 환원당 7.9 mg/ml, 전당 84 mg/ml였다. 향기성분은 아세트알데히드 6 ppm, 휴젤유 161 ppm, 에틸아세테이트 6 ppm이었다. 증류가 진행됨에 따라 에탄올, 메탄올, 휴젤유, 아세트알데히드, 에틸아세테이트는 감소하였으며 총산은 증가하였다. 대체적으로 총산을 제외하고는 상압보다는 감압에서 향기성분들은 감소하였다. 증류초기 1, 2, 3분액에서는 에탄올의 농도가 70%이상이었지만 5분액부터는 에탄올 함량이 급격히 감소하였는데 이때의 에탄을 함량은 50% 이하였다. 관능검사 결과 증류주의 특성은 총 16가지가 밝혀졌으며 그 중에서 항기성분이 4가지, 맛성분이 7가지, 그리고 후미가 5가지였다. 이들 특성중 증류주의 품질에 크게 영향을 미치는 특성은 누룩향과 시원한감 등이며 전체적인 품질은 충전상태, 260 mmHg의 2, 3, 4분액이 가장 높은 품질을 보였다. 이 분액의 성분은 메탄올 $24{\sim}36\;ppm$, 총산 $0.21{\sim}0.29\;g/100\;ml$, 휴젤유 $657{\sim}1340\;ppm$, 아세트알데히드 $12{\sim}41\;ppm$ 그리고 에틸아세테이트가 $22{\sim}311\;ppm$ 범위에 있었다.