Changes in vitamin C and chlorophyll contents and stability of chlorophyllase activity during storage of Tencha

Tencha is a kind of processed tea leaves which is used as material for powd ered tea, Matcha. To estimate the quality of Tencha with storages in air an d in nitrogen at 5 degrees C for 6 months, vitamin C, chlorophyll and its r elated derivatives contents and the stability of chlorophyllase activity in Tencha leaves were investigated. The residual rates of the apparent total vitamin C and ascorbic acid in Tencha were about 80% in air and 90% in nitr ogen after 6 months of storage, respectively. The apparent oxidized vitamin C remained constant during 6 months, Surface color ( a/b value) of Matcha (powdered Tencha), and contents of chlorophyll and its related derivatives in Tencha varied very little in both atmospheric conditions after 6 months of storage. Though chlorophyllase remained enough activity to react after 6 months-storage of Tencha, the enzyme did not cause the degradation of chlo rophyll in Tencha under the storage condition of low moisture. These result s indicate that Tencha have maintained satisfactory quality during the 6 mo nths-storage in air at 5 degrees C fur aging to favorable Matcha.