EFFECT OF MATURITY STAGES AND SOLVENT POLARITY ON PHENOLIC CONTENT AND ANTIOXIDANT CAPACITY OF GUAVA CULTIVARS

Abstract

Tropical fruits claim to have phenolic compounds that have been reported to possess strong antioxidant activity. The study investigatedantioxidant activity and total phenolic content of five Guava cultivars namely Allahabad Safeda, Allahabad Surkha, Lalit, Chittidar and Apple color harvested at three fruit ripening stages (unripe, semi-ripe and ripe) and extracted by four solvents (ethanol, methanol, acetone and water) with different polarities (50%, 70% and 100%).The findings suggest that guava cultivars with maturity stages and extracting solvent affected its phenolic content and antioxidant activity significantly. Pure solvents were inefficient extraction medium for antioxidants. Enhanced extraction yields were obtained from solvent containing higher water concentrations and 50% ethanol is a recommended solvent for extracting antioxidants compounds from guava fruit. High correlations between phenolic compositions and antioxidant activities of guava extracts were observed. The total phenolics and antioxidant capacity decreases as the ripening proceeds (unripe>semi-ripe>ripe) in all five cultivars.This study facilitates information on the total phenolic content and antioxidant capacities of guava cultivars which is an important commercial fruit. Results obtained showed that solvent polarities and ripening stages played the major role in extraction of ployphenolics from Guava. The significant declines in the levels of total phenolics and antioxidant capacity during fruit development suggest that the unripe fruits can also be taken for processing into nutraceutical foods.