Varietal Differences among the Phenolic Contents and Antioxidant Activities of White and Red Fleshed Guava during Maturation and Ripening Stages

Guava (Psidium guajava L.) is an important commercial fruit in southern China. In this study, the antioxidant activity and total contents of phenolics and flavonoids of two guava cultivars that with different pulp color were examined. The contents of total phenolics and flavonoids increased during maturation in guava fruit. And red-flesh guava showed higher contents of total phenolics and flavonoids than white-flesh guava. Both DPPH and FRAP assays indicated that antioxidant activity increased during fruit maturation. Strong and positive correlations between total phenolics, total flavonoids and antioxidant activity were observed in our study. Our results suggest that the antioxidant activity and contents of total phenolics and flavonoids in P. guajava vary significantly among different cultivar and pulp color.