Antioxidant Activity of Ethanolic Onion Skin Extracts Produced by Microwave Assisted and Conventional Extraction Methods

This experiment focused on determination of antioxidant activity onion skin (OS), extracted by three techniques i.e. Microwave Assisted Extraction (MAE), Soxhlet and Maceration with different ethanol (EtOH) concentrations. Total Phenolic Content (TPC) Flavonoid (TFC) were estimated Folin-ciocaltteu method Aluminium Chloride respectively. Antioxidant (AOA) was assessed Diphenyl Picryl Hydrazyl (DPPH) Half-maximal inhibitory concentration (IC50) value recoded. The maximum TPC TFC found as 519.25 mg/g gallic acid equivalent (GAE) 120.975 Quercetin (QE) respectively, using 90% EtOH microwave at 300W. (90%) OS extracts showed the highest free radical scavenging power 400W 86.980% an IC50 38.516µg/ml. In all assay, MAE higher TPC, activity, suggesting that is a suitable for extraction component from OS.