Optimization of Extraction Technology for Polyphenols from Grape Skin

Polyphenolic compounds were extracted from grape(Vitis vinifera) skin using heat extraction method.Single-factor tests and orthogonal design were applied to study the effects of extraction conditions such as extractant,extraction temperature,extraction time and material to liquid ratio on yield of polyphenols and to optimize the extraction technology.The results showed that the optimum extraction conditions for polyphenols from grape skin were,methanol-ethanol-acetone(volume fraction 100%,volume ratio 1∶1∶1) as extractant,material to liquid ratio mgrape skin∶ Vextractant=1∶14(g / mL),extraction temperature 60 ℃,extraction time 40 min.The yield of polyphenols from grape skin could reach to 16.866 mg / g under these conditions.