Influence of genotype and manufacturing process on the activity of β-D-glucosidase and β-galactosidase in tea

Abstract

Tea flush shoots comprising three leaves and a bud were harvested from 20 different cultivars planted in a single area of UPASI Tea Research Farm and analyzed for β-D-glucosidase and β-galactosidase activities. Among the cultivars studied a range of variability of 0.63 to 5.45 units of β-galactosidase activity and 0.06 to 1.91 units of β-D-glucosidase activity was observed. This result suggested the influence of genotype on these enzymes. The activity was higher in actively growing tea tissues (bud) and lowest in bark ofthe tea plant. At any given stage of black tea manufacture β-galactosidase activity was higher than that of β-D-glucosidase. During manufacturing process the activity of both enzymes varied widely and remained maximum in withered leaves. The insignificant conelation coefficient obtained for these two enzymes with productivity suggest that they cannot be used as one ofthe biochemical tools to predict the yield potential of tea cultivar. The flavour analysis carried out in greenleaf, withered leaf, cut dhool, fermented dhool, made tea and tea brew indicated that not even a single flavour compound was found maximum in green leaf. This provides important information that most of the flavour compounds are produced after harvest. © 2007 Academic Journals.