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Tannase application in secondary enzymatic processing of inferior Tieguanyin oolong tea
Li, Jiajia; Xiao, Qiong; Huang, Yufeng; Ni, Hui; Wu, Changzheng & Xiao, Anfeng
Abstract
Background: Inferior Tieguanyin oolong tea leaves were treated with tannase. The content and bioactivity of
catechins in extracts from the treated tea leaves were investigated to assess the improvement in the quality of
inferior Tieguanyin oolong tea.
Results: Analysis showed that after treatment, the esterified catechin content decreased by 23.5%, whereas
non-galloylated catechin and gallic acid contents increased by 15.3% and 182%, respectively. The extracts from
tannase-treated tea leaves showed reduced ability to bind to BSA and decreased tea cream levels. The extracts
also exhibited increased antioxidant ability to scavenge OH and DPPH radicals, increased ferric reducing
power, and decreased inhibitory effects on pancreatic α-amylase and lipase activities.
Conclusions: These results suggested that tannase treatment could improve the quality of inferior Tieguanyin
oolong tea leaves.
Keywords
Antioxidant capacity; Assess; Catechin; Catechins; Inferior tea; Quality improvement; Secondary processing; Tannase-catalyzed hydrolysis; Tea infusion; Tea leaves
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