The pigments of green tea consist of chlorophylls and carotenoids. Chlorophylls are dominant pigments of fresh
green tea leaves3
, but easily degrade, turning into pheophytin and pheophorbide after heating and storing
processes3-6. In green tea, pheophorbides content is lower than pheophytins. This is due to the fact that the
chlorophylase enzyme is made non-active during the post-harvesting and steaming process whereas the formation of
pheophytin is attributable to the storing process3
. During the increase in storage time, the acidity is also increasing.
The result is a reaction between chlorophylls and acids, in which acid removes the magnesium ion and replaces it
with two hydrogen atoms giving an olive-brown solid, pheophytin.
The formation of pheophytin occurs in vivo as well as in vitro. Pheophytin occurs naturally in the plant leaves and
is important as the first electron carrier intermediate in the electron transfer pathway of photosystem II in plants.
Furthermore, pheophytin has been reported to have antioxidant activity7
. Here, we report our preliminary study in
isolation and identification of pheophytin from green tea leaves as well as to assay the antioxidant activity of it.