Changes of the flavonoid and phenolic acid content and antioxidant activity of tartary buckwheat beer during the fermentation

摘要

Through determinate the changes of composition and activity during the fermentation period of buckwheat beer, then analyzed the relationship by used SAS 9.0 software. Determined the monomer flavonoid, monomer phenolic acids by HPLC, antioxidant activity by against the ABTS and DPPH. The results show that the amount of total flavonoid (from 0.607±0.047 g·L~(-1)to 0.519±0.038 g·L~(-1) ), total phenolic acids (from 0.690±0.060 g·L~(-1) to 0.395±0.034 g·L~(-1))change during fermentation. Tartary buckwheat beer exhibits strong DPPH (103.904±0.361 VCEAC mg·L~(-1)) and ABTS (25.018±0.268 VCEAC mg·L~(-1)) radical scavenging activities. The rutin, quercetin, ferulic acid, caffeic acid, protocatechuic acid, and p-coumaric acid show a downward trend, however, the isoquercitrin, gallic acid display the rising trend. At the same time, the regression equation as Y_2 (Total phenolic) = 0.31595 + 2.10834X_5 (Quercetin)(P<0.05), Y_3 ( ABTS[VCEAC] ) = 47.75299 - 23.78253X_8 (Ferulic acid)(P, 0.05).