Antioxidant activity and physicochemical properties of mature papaya fruit (Carica papaya L. cv. Eksotika)

Abstract

Papaya (Carica papaya L. cv. Eksotika) is one of the most commonly consumed tropical fruits by humans, especially Malaysians. The objective of this study was to evaluate the effect of the maturity stage (12, 14, 16, 18 and 20 weeks after anthesis) of papaya fruit on its physicochemical properties, antioxidant capacity and sensory characteristics. Papaya fruits were selected and classified based on their visual maturity, i.e., stages 1 to 5. The activities of several antioxidants were tested, including the Total Phenolic Content (TPC), Total Flavonoid Content (TFC), Ferric Reducing Antioxidant Power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis- 3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The physicochemical changes were measured in terms of the pH, Titratable Acidity (TA), moisture, Total Soluble Solids (TSS) and pulp color of the papaya fruits at the five ripening stages. Significant differences (p<0.05) were found in different degrees of ripening. The pH of the fruit decreased significantly (p<0.05), whereas the TA, moisture and TSS all increased significantly (p<0.05) with maturity. The redness (a*) and yellowness (b*) values of the fruit color both increased significantly, whereas the lightness (L*) of the color fluctuated. The TPC, TFC, FRAP, DPPH and ABTS values also increased significantly (p<0.05) with ripening. Sensory evaluation based on the color, sweetness, sourness, flavor and overall acceptance for the last three maturity stages was also performed. Stage 5 had a better score than stages 3 or 4. The results showed the important role of the ripening stage in increasing the antioxidant content of papaya fruits. © Maxwell Scientific Organization, 2013.