“…There are many studies on green tea polyphenols especially associated with extraction conditions such as solvent type, extraction time, extraction temperature, agitation and loading percentage (Hertog et al,1993;Khokhar & Magnusdottir, 2002;Perva-Uzunalić et al, 2006;Xi et al, 2009;Komes et al, 2010). Also according to Wang & Helliwell (2001), the extraction efficiency of polyphenols depends on the extraction time, temperature, pH and type of solvents.…”