Abstract:The differences in the flavor components of fermented rice wine varieties (Yichang, Wuxi, Suizhou, and Nanning local koji) were compared by optimizing the process for the fermentation of koji from four regions using an orthogonal test, and the basic physical and chemical indexes of the four kinds of fermented rice wine were determined. An electronic tongue was used to analyze the flavor characteristics of the four kinds of rice wine, and the differences in the flavor characteristics were compared by principal component analysis. The volatile flavor components of the four kinds of rice wine were determined by headspace solid-phase microextraction (HS-SPME-GC-MS). The optimum brewing temperature, time, and inoculum amount of koji for Yichang, Wuxi, Suizhou, and Nanning were 32 ℃, 60 h, 0.2%; 28 ℃, 60 h, 0.4%; 28 ℃, 60 h, 0.6%; and 32 ℃, 48 h, 0.6%, respectively. The pH of the four kinds of fermented rice wine was in the range of 3.88~4.01, where the difference was not significant. Yichang rice wine had the highest content of reducing sugar (431.53 mg/mL), where the content differed significantly among the four kinds of rice wine (P<0.05). There were significant differences in the flavor of the rice wine produced from koji in different regions, among which Nanning rice wine had the best flavor, with moderate acidity and sweetness and a rich taste. This wine had the most types of ester flavor compounds and the highest relative content, and had a rich and mellow flavor. Wuxi rice wine and Suizhou rice wine were different in color, flavor, taste, and organizational state, and the overall flavor was also different. Compared with the other three kinds of sweet rice wine, Yichang rice wine has the highest sweetness, but its taste and flavor were relatively simple. This study distinguished the unique flavor characteristics of koji fermented rice wine from different regions and provides a reference for improving the quality of traditional rice wine and maintaining the regional characteristics.
