Antioxidant activities from various bulbs extracts of three kinds allium using DPPH, ABTS assays and correlation with total phenolic, flavonoid, carotenoid content

The antioxidant activities of various bulbs extracts of three kinds Allium were conducted by DPPH (2.2-diphenyl-1-picrylhydrazyl) and ABTS (2-2’-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) assays. Sample O2 (ethyl acetate extract of onion bulbs) had the highest DPPH scavenging capacity (45.86 %.) and the highest ABTS capacity (49.03 %). Sample RO2 (ethyl acetate extract of sample red onion) contained the highest total flavonoid (89.3 g QE/100 g) and the highest phenolic contents (40.75 g GAE/100 g), while the highest carotenoid 7.4 g BET/100 g was given by RO1 (n-hexane extract of sample red onion). Phenolic and flavonoid were the major contributors to antioxidant activity in onion and red onion bulbs. The total carotenoid of three Allium bulbs extracts had no significant correlation with DPPH and ABTS scavenging activities. There were positively high correlation between ABTS and DPPH scavenging capacities for sample O and RO, but no correlation for sample G (garlic).