청주(淸酒)의 주모(酒母)담금액(液)을 달리하여 발효과정(醱酵過程)중에 pH, 산도(酸度), Nitrate, Nitrite, DMA의 변화(變化)와 발효종료(醱酵終了)후의 NDMA를 검토(檢討)한 결과(結果)를 요약(要約)하면 다음과 같다. 발효기간(醱酵期間)중 pH는 발효(醱酵) 24시간 이후부터 일반적으로 pH 5.0 이하로 떨어졌고 발효종료(醱酵終了) 후의 산도(酸度)는 $0.51{sim}0.89$ 이 있다. 주모발효과정(酒母醱酵過程)중 Nitrate의 함량(含量)은 12시간 이후부터 급격히 감소(減少)되었고 Nitrite는 酸度의 영향으로 발효(醱酵) 초기(初期)에 다량생성(多量生成)되었다가 완전히 소실(消失)되었으며 DMA는 각(各) 실험구별(實驗區別) 차이는 있으나 일정(一定)한 수준(水準)을 유지하였다. 발효종료(醱酵終了) 후 NDMA는 Nitrite와 DMA 첨가구(添加區)에서 472.1ppb, DMA에서는 329.0 ppb, Nitrite에서는 229.0 ppb 대조구(對照區)에서는 24.4 ppb 이였으나 시판(市販) 청주(淸酒)에서는 검출(檢出)되지 않았다.
The changes of pH, titrable acidity, nitrite and dimethylamine(DAM) content in the various different kinds of the rice wine staters during the fermentation were studied, and the changes of nitrosodimethymaine(NDMA) contents were also determined by High Pressure Liquid Chromatography. After 24hrs, fermentation rice wine starter, pH was generally decreased to below 5 and after full fermentation the acidities were from 0.51 to 0.89 as succinic acid. After 12hrs, fermentation nitrate contents were rapidly decreased. The large amount of nitrite was formed in the beginning of the fermentation. But by the increase in the acidity due to the further fermentation nitrite contents were gradually disappeared. Generally the DMA contents of each rice wine starter were kept unchanged. On completion of fermentation, NDMA contents of starter added with nitrite and DMA were 472.1 ppb. The starter added with DMA was 329.0 ppb, whereas the other added with nitrite was 229.0 ppb, and control without addition of nitrite and DMA was 24.4 ppb. But the rice wine sold in market was not detected any NDMA at all.
