Evaluation of Antioxidant Properties of Phenolics Extracted from Ananas comosus L.

Abstract

Phenolics were extracted from the fruit tissues of Ananas comosus L. var. queen, cv. 'Meitei Keehom', a variety of pineapple grown in Manipur, India, after skin peeling, purified and their antioxidant properties were analyzed. The antioxidant properties were assessed based on the ability of fruit phenolics in absolute methanol to scavenge DPPH, superoxide anion radicals and hydroxyl radicals and compared to antioxidant compounds like ascorbic acid and pyragallol. Pineapple fruit phenolics scavenged DPPH, superioxide anion radicals and hydroxyl radicals in a dose dependent way. In DPPH assay, the IC50 values of pineapple phenolics, ascorbic acid and pyragallol were 12.2μg/ml, 17.82μg/ml and 15.92μg/ml respectively. In superoxide anion and hydroxyl radical scavenging activities, the IC50 values of pineapple phenolics were 11.42μg/ml and 55.292μg/ml, for ascorbic acid 49.62μg/ml, 48.52μg/ml and that of pyragallol was 15.672μg/ml and 60.62μg/ml. The IC50 value was lowest in pineapple phenolics than ascorbic acid and pyragallol in DPPH and superoxide anion assays. But it is higher than ascorbic acid and lower than pyragallol in hydroxyl radical assay. The lower the IC50 values, the higher the antioxidant activities. The phenolics extracted from this variety of pineapple exhibit excellent free radical scavenging activity. The result shows that pineapple and its active constituents may be used in further antioxidative therapy.