Comparison Antioxidant Properties Extract of Touyserkani Variety of Walnut Leave with two Extraction Methods (Traditional Method and Microwave Assisted Extraction)

Abstract

The aim of this study is extraction of phenolic compounds from walnut leaves of touyserkani variety with two extraction methods (traditional method and with microwave assisted extraction (MAE)) and evaluation of their antioxidant activity. Total Phenolic contents and antioxidant properties of aqueous, methanol (80%) and ethanol (50%) extracts in different times was determined. At the next stage, effect of methanol extract on retarding of oxidation of soy oil was assessed. All of extracts showed antioxidant activity in a concentration-dependent way. In MAE, methanol extract had highest total phenol whose content is 89.15 ± 0.25 mg/g. the ethanol extract presented highest activity in radical-scavenging activity (EC50 = 27.90 µg/ml), reducing power assay (EC50 = 93.26 µg/ml) and antioxidant activity assay (EC50=68.23 µg/ml). Also extract at 1000 ppm could control oxidation of soy oil and this extract was effective than all of synthesis antioxidant in retarding oil oxidation Hence we can present walnut leaves as a potential source of phenolic compounds and natural antioxidant.