A pilot study on the antioxidant activities of fresh and processed papaya leaves

Abstract

Background: Herbal plants and natural products have long been recognized for their antioxidant activity. Papaya is a popular plant in Thailand. Papaya leaf products are manufactured and sold in various forms. However, comparative studies on the antioxidant activity of papaya leaf products in different forms, such as fresh versus processed, remain limited.

Objective: To investigate the total phenolic content (TPC) and antioxidant activity, and to compare the antioxidant capabilities of papaya leaves in different forms.

Methods: Papaya leaves (n = 10) were collected from a papaya tree located in Thailand and prepared as freezedried leaf juice. Papaya leaf capsules and tea are supplements that manufactured and sold in Thailand. 1,1- diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, ferric reducing antioxidant power (FRAP), and TPC were determined for the methanolic extract of papaya leaves and their products.

Results: Freeze-dried papaya leaf juice exhibited the highest FRAP and TPC values, which were significantly higher than those of the other samples (P < 0.05). Meanwhile, papaya leaf capsules showed the highest antioxidant activity in the DPPH assay, but the difference was not statistically significant compared to freeze-dried papaya leaf juice (P < 0.05).

Conclusion: The results indicate that the combination of compressed juice followed by freeze-drying is the most effective method for preserving the antioxidant activity of papaya leaves.