Changes in the bioactive compounds and antioxidant activity in red-fleshed dragon fruit during its development

Abstract Red-fleshed dragon fruit (Hylocereus polyrhizus) is a promising food with a functional appeal. This study investigated the changes in the bioactive compounds and antioxidant activity of the red-fleshed dragon fruit at eight development stages. In general, the levels of total phenolic compounds tested using Folin-Ciocalteu, and Fast Blue BB reagents, betacyanin, betaxanthin, anthocyanins, and antioxidant activity by TEAC, FRAP, and s-carotene bleaching increased over the fruit development stages, whereas vitamin C content significantly decreased. Six phenolic compounds were identified, including catechin, vanillin, gallic acid, caffeic acid, chlorogenic acid, and ferulic acid. Catechin was the majority compound, followed by vanillin. All these compounds decreased during fruit development; chlorogenic and ferulic acids were only detected 30 days after anthesis. Based on the results, the suitable harvest period of red-fleshed dragon fruit is between 36 and 38 days after anthesis.