Abstract:The Rabbiteye blueberry was used as raw material to study changes in phenolic contents and their antioxidant activities during its fermentation. The results showed that during the fermentation of blueberry wine, the trend of increased first and then decreased was observed in the contents of total flavonoids, total polyphenols and anthocyanins, as well as the iron-reducing ability, the DPPH free radical scavenging rate and hydroxyl free radical scavenging rate. Color analysis showed that the L* value increased before decreasing, and it fluctuated and increased in the later stage of fermentation; the a* value increased gradually, and then fluctuated and decreased in the later stage of fermentation. There were positive correlations between the a* value and anthocyanin content and between the b* value and total polyphenol and total flavonoid contents. No p-hydroxybenzoic acid was detected during the fermentation of blueberry wine, while vanillic acid content increased significantly (p < 0.05). The contents of nine phenolic acids, namely, gallic acid, protocatechuic acid, gentisic acid, chlorogenic acid, caffeic acid, syringic acid, p-cumaric acid, ferulic acid, and sinapic acid, significantly increased (p < 0.05) during primary fermentation, and significantly decreased (p < 0.05) at the end of fermentation, but were still significantly higher (p < 0.05) than the contents of those acids in the initial stage of fermentation. Contents of hydroxybenzoic phenolic acids, hydroxycinnamic phenolic acids, and total phenolic acids increased before decreasing.
