Optimization of flash extraction process and antioxidant activity of polyphenol from red raspberry

The extraction processing of total polyphenols from red raspberry was performed and investigated According to the result of single factor experiments,solvent concentration,extract time and voltage were further selected for Box-Behnken center design. The response surface methodology was applied to optimize the extraction conditions. The antioxidant activity was measured by in vitro DPPH and OH radical scavenging analysis. DPPH· and ·OH. The efficiency for extraction of total polyphenols from red raspberry in four solvents was in following order:ethanol > water > petroleum ether > chloroform. The optimal condition for extraction of total polyphenols were the solvent of ethanol,voltage 150 V,time 57 s. with the extract ratio of 48% and the yield of(52.24±0.66) mg/g dry weight. In addition,the DPPH and OH radical inhibitory effects were 93.71%±0.70%,and 84.13%±1.58%,respectively.