غلامرضا عبدی

The current study aimed to measure antioxidant potential of Withania somnifera and its ability to protect quality of crude soybean oil at 170 °C for different time intervals. GC–MS analysis of plant powder was conducted. Ethanol, methanol, acetone, hexane and aqueous ethanol extracts were used to perform TPC, TFC, DPPH, and ABTS analysis. Thermal stability of soybean oil was assessed by monitoring quality parameters (POV, FFA & acid values) by adding different extract concentrations (0.125 %, 0.25 % & 0.5 %) and 0.02 % BHA was a positive control. It was observed that methanolic extract of W. somnifera leaves had highest TF contents (86.65±0.03 mg QE/100 g) and showed maximum DPPH Inhibition of 93.56 %, moreover, ethanolic extracts of W. somnifera leaves had maximum TP contents (1001.3 ± 6.51 mg GA/100 g) and ABTS value (1.71±0.01 µM Trolox/g). GC–MS revealed maximal presence of 3-eicosyne, hexahydrofarnesyl acetone, 3-icosyne, 9-eicosyne and hexadecanoic acid methyl ester. Hexane & methanolic extracts of W. somnifera leaves depicted comparatively better protection ability at 0.25 % & 0.5 % concentration than BHA.