Abstract

The fruits G. asiatica, E. jambolana and C. carandas were extracted with methanol and the extracts were partitioned into four polyphenolic fractions: Flavanols, flavonols, phenolic acids and anthocyanins using solid phase extraction. Each fraction was then analyzed for total phenolics, flavonoids, antioxidant activity by DPPH, beta-carotene-linoleic acid assay and total reducing power. Total phenolics ranged 6.64-107, 56.20-398, 33.38-315 and 20-201 mg/100 g in phenolic acid, flavanol, flavonol and anthocyanin fractions respectively of these fruits which explained the order of their antioxidant activity and reducing power as flavanols > flavonols > anthocyanins > phenolic acid. Total phenolics were highest in E. jambolana fractions (107-398 mg/100 g) but the maximum antioxidant activity (62-85% in 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 58-89% in ?-carotene-linoleic acid assay) was shown by the fractions in G.asiatica (total phenolics, 67-151 mg/100 g). At all concentrations, the DPPH scavenging activity of flavanol fraction in G. asiatica (85% at 20 ppm) was comparable to BHA (89%).

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