A dpph· kinetic approach on the antioxidant activity of various parts and ripening levels of papaya (Carica papaya l.) ethanolic extracts

Abstract

Papaya fruits (Carica papaya L.) are valuable both as food, including concentrates and mixed beverages and in traditional medicine. The goal of the study was to evaluate the antioxidant activity of various parts of unripe and ripe papaya fruit from the DPPH· kinetics point of view. Peel, pulp, seed, and seed-pulp of unripe and ripe papaya fruits (¼ and >¾ level of ripening) were ex-tracted with ethanol and monitored at 517 nm in the presence of DPPH·. The radical scavenging capacity (RSC) at various time ranges and DPPH· reaction rates for specific time intervals were de-termined. The highest RSC values were obtained for papaya pulp extracts, consistently higher for the ripe samples in comparison with the unripe ones (86.4% and 41.3%). The DPPH· rates significantly differ for the unripe and ripe papaya extracts, especially for the first time range. They are more than double for the ripe papaya. These values were 2.70, 4.00, 3.25, 2.75 μM/s for the peel, pulp, seed, seed-pulp extracts from the ripe papaya and only 1.00, 1.65, 1.40, 1.80 μM/s for the unripe samples. DPPH· kinetic approach can be useful for a fast and simple evaluation of the overall anti-oxidant properties of fruit extracts.