Effect of different moulds on oenological properties and flavor characteristics in rice wine

Rice wine is one of traditional alcoholic beverages in China, which were fermented from rice with moulds and yeasts. In this study, in order to determine the difference in rice wine brewed by four moulds, four types of rice wine (named as HIM, BM, HEM, and GM) on physical and chemical factors, free amino acids (FAAs), volatile and non-volatile metabolites, and sensory evaluation were investigated. Results showed that 17 FAAs, 186 volatile compounds and 489 non-volatile metabolites were detected in rice wine. However, metabolites of rice wine brewed by moulds were quite different, in HIM rice wine, the content of FAAs (2861.62 ± 109.49 mg/L), alcohols (32.91 ± 3.37 mg/L), esters (19.34 ± 0.69 mg/L) and phenols (10.89 ± 0.27 mg/L) were the highest among rice wine samples. The number of different non-volatile metabolites in four rice wine samples were 27, 20, 62, and 20 (HIM, GM, HEM, and BM) by Linear Discriminant Analysis Effect Size respectively. And most of these non-volatile metabolites were organic acids (pyruvic acid, shikimic acid, etc.). Sensory evaluation showed that rice wine (HIM) brewed with Aspergillus oryzae were better than other rice wine samples.