Process Biochemistry, Vol.82, 51-58, 2019
Role of carbohydrate-cleaving enzymes in phenolic mobilization of guava leaves tea during solid state bio-processing with Monascus anka and Bacillus sp
The purpose of this study was to investigate the effect of carbohydrate-cleaving enzymes produced by Monascus anka and Bacillus sp. in the phenolic mobilization during guava leaves tea (GLT) bio-processing. The results showed solid state bio-processing (SSB) greatly increased the contents of soluble phenolic and flavonoid aglycone in GLT. During SSB, the activities of alpha-amylase (83.05 U/g) and total cellulase (31.32 U/g) were high, while those of xylanase (5.27 U/g) and beta-glucosidase (0.19 U/g) were relatively lower. There was a good correlation between the content of soluble phenolic released from GLT and the activities of alpha-amylase, cellulase and beta-glucosidase, while a low correlation between the content of soluble phenolic and the activity of xylanase. Moreover, the contents of soluble phenolic, especially quercetin and kaempferol, in GLT treated with mixture of pure enzymes significantly increased. The study provides theoretical basis for the phenolic mobilization of plant matrices during SSB and lays a solid foundation for seeking more efficient methods for enhancing the efficacy of tea infusions.