STUDY ON POLYPHENOL EXTRACTION FROM DUST GREEN TEA. PART 1. THE INFLUENCE FACTORS ON POLYPHENOL EXTRACTION

Abstract

Traditionally,  green  tea  extract  is  obtained  by  water  or  organic  solvent  extraction.  In this

paper,  polyphenol  extraction  was  carried  out  by  using  water  extraction  from  dust  green  tea,

harvested  from  Phu Ho, Phu Tho province. The aims of the study  is to investigate the  influence

factors  on the efficiency  of the extraction of polyphenols (a functional  group with many precious

biological  activities)  from  dust  green  tea.  Tea  extract  was  analysed  for  the  content  of  total

polyphenols  by  Folin-Denis  method  and  the  antioxidant  activity  of this  extract  was  determined

by DPPH free  radical  scavenger  activity. This work was focused  on researching  of several main

influence  factors  on the extraction  of polyphenols  from  green  tea  including extraction  time, pH,

solvent/material  ratio and extraction  temperature. The range of these  factors  to get high yield of

both  polyphenols  and  antioxidant  activity  were  45  - 60  min;  2,5  -  3,5;  10/1  -  15/1  and  SOT -

90°C, respectively.