Abstract:To better understand the effect of different factors on the phenolics and antioxidant activities of wine during rice wine fermentation, 6 kinds of rice materials were used to ferment sweet rice wine by traditional solid-state fermentation process. The total polyphenol content and main phenolic components of rice wine were determined by Folin - Ciocalteu method and high performance liquid chromatography, respectively. The antioxidant activity of rice wines was detected according to ABTS free radical scavenging rate and ferric reducing antioxidant power (FRAP), and the correlation between polyphenol content and antioxidant activity of rice wines was analyzed and the principal component analysis was also performed. The results showed that the polyphenol content of black rice wine was the highest, 1 135.33 mg/L gallic acid equivalent, while the total polyphenol content of yellow rice wine was the lowest, 144.53 mg/L gallic acid equivalent. There were significant differences in total phenol content among the 6 kinds of rice wine, indicating that the polyphenols in rice wine mainly come from their rice raw materials. In addition, there were significant differences between the antioxidant activities of rice wine fermented with 6 kinds of rice materials. Correlation analysis showed that the linear correlation coefficients between the antioxidant values of ABTS method and FRAP method and total polyphenol contents of 6 kinds of rice wines were 0.829 (P = 0.042) and 0.886 (P = 0.019), respectively, indicating that there was a certain correlation between the antioxidant activities of rice wines and polyphenol contents. The main polyphenol composition determined by HPLC showed that the contents of p-hydroxybenzoic acid and erucic acid in black rice wine and purple rice wine were higher. Principal component analysis showed that the polyphenol composition and content of rice wine fermented with black rice and purple rice were different to some extent, compared with the other 4 kinds of rice wines. This study will provide a theoretical and practical basis for the biological brewing, nutrition and functional optimization of rice wine.