Extraction of peanut skin total polyphenols by microwave combined-Assisted ethanol method

Objective:Peanut skin is a by-product of peanut milk from peanut,and it is rich in antioxidants such as polyphenoles.The paper aimed to obtain the optimum extraction conditions of peanut skin total polyphenoles by microwave combined-assisted ethanol method.Methods:Ratio of stuff to solvent,concentration of ethanol,extraction time and the power of microwave were designed to obtained the range of the parameters to the effect on extraction of the polyphenoles,then the experiments based on four factors orthogonal design were further to optimize the extraction conditions.The content of the ployphenoles were determined by UV of gallic acid.Conclusion:The optimum technic parameters were obtained that ratio of stuff to solvent was 1:25,and concentration of ethanol was 75%,and extraction time was 2 mins,and the power of microwave was 540W,and the extraction rate of the total ployphenoles in peanut skin was reached to 183.25±8.62mg/g after five experiments under the optimum technic parameters.