In the course of our study on aroma formation mechanism of oolong tea, we have isolated and identified geranyl, (S)-linalyl salicylate, benzyl, 2-phenylethyl, trans- and cis-linalool 3,6-oxide 6-O-β-D-xylopyranosyl-β-D-glucopyranosides (β-prim- everoside) from the leaves for oolong tea (Camellia sinensis war. sinensis cvs Shuixian and Maoxie) by means of a crude enzyme assay. Aroma precursors of trans- and cis-linalool 3,7-oxides, and (Z)-3-hexenol were exceptionally isolated as 6-O-β-apiofuranosyl-β-D-glucopyranosides and β-D-glucopy-ranoside, respectively. And, in order to know the molacular basis of tea aroma formation mechanism, we measured changes of alcoholic aroma precursor amounts and glycosidase activity in each part of tea shoot (cv Yabykita). Amounts of aroma precursors were abundant in young leaves and decreased as leaf aged. Glycosidase activity also decreased as leaf aged, but was high in stem. We also purified and characterized a new glycosidase (β-primeverosidase) from fresh leaves of cvs Yavukita and Shuixian for green tea and oolong tea, respectively. This enzyme was found to be one of the main glycosidase concerned with the alcoholic aroma formation in tea leaves.
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