Abstract
This study was conducted to determine whether pectinase treatment would affect the process of alcohol fer-mentation with persimmon. The pectinase did not change pH and total acidity throughout the alcohol fermentation. However, the concentrations of reducing sugar were significantly lowered with the fermentation time, compared with controls. During the alcohol fermertation, the concentration of reducing sugar decreased rapidly up to 60 hours, unchanged from 60 to 72 hours, and then increased thereafter. The total alcohol concentrations of pectinase-treated groups were significantly higher than that of alcohol fermentation containing without pectinase. Among concentration 200 and 500 ppm had the most pronounced increase in the yield (%) of total alcohol (96%, respectively) and then, 300, 400 ppm and control in descending order. The contents of 5 major alcohols (acetaldehyde, methanol, n-propy alcohol, iso-butyl alcohol and iso-amyl alcohol) were measured. Among alcohol constituents, acetaldehyde and methanol were detected to be the lowest at control and methanol the highest at 200 ppm. These observations indicated that pectinase treatment would increase the yield of total alcohol, whereas it also raised methanol production during persimmon alcohol fermentation.
감과실의 효율적 활용을 위하여 알콜발효과정에서 pectinase 처리에 따른 성분 변화를 조사하였다. pH 및 총산의 변화는 모든 구간에서 크게 나타나지 않았으며 pectinase 처리에 따른 영향은 없었다. 환원당 함량의 변화는 실험구간 모두 발효시간 12시간 이후 급격히 감소하여 60시간부터는 변화가 없었으며 72시간에서는 pectinase처리 구간이 약간 높게 나타났다 알콜 함량의 변화는 무처리구보다 pectinase 처리구들이 높게 나타나는 경향이었으나 농도에 따른 차이는 크게 나타나지 않았다. 알콜발효수율은 200, 500 ppm 처리구가 96%로 가장 높았으며 다음은 300, 400 ppm 및 무처리구 순서로 높게 나타났다. 알콜발효과정에서 주요 알콜성분은 acetaldehyde, mothanol, ethanol, n-propylalcohol, iso-butylalcohol 및 iso-amylalcohol 5종이 분석되었다. Acetaldehyde 및 methanol 함량은 무처리구가 가장 낮았으며 methanol의 함량은 200 ppm처리구가 가장 높았으나 pectinase 처리 및 농도에 따른 차이는 크게 나타나지 않았다. 이상의 결과 감과실 알콜발효과정에서 pectinase 처리는 알콜수율 증가 등에는 효과적이었으나 methanol 함량은 증가시키는 것으로 나타났다.
