Investigation of the Methods for Converting Percentage of Chlorophyll to Pheophytin in Green Tea Leaves

Abstract

There are three methods for the measurement of converting percentage of chlorophyll to pheophytin in green tea leaves. Characteristics of these methods were investigated. For the first method reported originally, the converting percentage is obtained colorimetrically using the empirical calculating equation. This has merits of simplification and lower running expense, while it has demerits of lower accuracy and applicability. The second method which improved the first one also has a demerit of lower applicability, nevertheless it is more excellent in the other comparative points. The third method, in which the converting percentage is calculated based on the individual pigment contents obtained by HPLC, has merits of high accuracy, reproducibility and applicability, while it has demerits of using the expensive apparatus and high-price standard pigments. These results suggest that the second method is the best from a standpoint of wide-spread utilities.