STUDY ON POLYPHENOL EXTRACTION FROM DUST GREEN TEA. PART 2. OPTIMIZATION OF POLYPHENOL EXTRACTION USING DESIRABILITY METHODOLOGY

Abstract

In this  study,  polyphenol  extraction  from  dust  green  tea  was  performed  by  water  solvent. The tea extract was analysed  for the content of total polyphenols by  Folin-Denis method and the antioxydant  activity  of  this  extract  was  determined  by  DPPH  free  radical  scavenging  effect. Thus polyphenol  extraction  was optimized  by using desirability  methodology  with  experimental
order  of  central  composite  orthogonal  design  (CCOD).  Four  main  effective   factors  namely temperature,  pH,  solvent/material  ratio  (v/m)  and  extraction  time  were  studied.  The  statistical analysis  showed  that  in  studied  range  the  solvent/material  ratio  and  temperature  have  had significant   effects   on  extraction  yield;  meanwhile  antioxydant  activity  was  influenced  by temperature, pH and solvent/material  ratio. The optimal  condition  for  polyphenol  extraction was as  followings:  extraction  time  42  minutes,  pH  2.9,  solvent/material   ratio   10/1  (v/m)  and extraction  temperature  77°C.  Extraction  yield  and  antioxydant  activity  have  reached  to 63.12%,
49.30%, respectively.