1999 Volume 1999 Issue 87 Pages 13-19
Qualities and properties of commercially available green teas were investigated on the basis of chlrophyll and its related derivatives contents.
(1)Pigments contents among the different types of tea
The Ooishita-cha, Maccha and Gyokuro, contained more chlorophyll (Chl) (a+a') and (b + b'), on the contrary, less pheophytin (Phy) (a + a') and (b + b') than Fukamushi sencha. Furthermore, the changing rate of Chl into Phy and the ratio of Chl (b + b') to Chl (a+ a') in Ooishita-cha were less than Fukamushi sencha. Sencha was in the middle between Ooishita-cha and Fukamushi sencha.
(2)Pigments contents among the different grades of tea
(a)In Maccha, Gyokuro and Sencha, the higher grades of tea contained more Chl (a+a') and (b + b'). Fukamushi sencha gave the opposite results. However, there were not signifi-cant differences in the contents among the different grades of tea. (b) In all types of tea, the higher grades of tea contained less Phy (a+a') and (b+b'), and the differences in the contents were markedly clear. (c) In all types of tea except for Fukamushi sencha, the higher grades of tea gave the less changing rate of Chl into Phy, and the differences in changing rate were markedly clear in Gyokuro and Sencha. (d) In all, types of tea except for Fukamushi sencha, the higher grades of tea gave the less Chl (b+b')/Chl(a+a') ratio. Especially, the differences were clear in Sencha.
The contents of Phy (a + a') and (b + b'), the changing rate of Chl into Phy, and the Chl (b+b')/Chl(a+a') ratio might be used as an indicator for the estimation of tea quality in Maccha, Gyokuro and Sencha. For the more presice estimation, it is effective to use these informations together. It is difficult for Fukamushi sencha to estimate its quality on the basis of the only pigments contents.