Unraveling the biochemical and pharmacokinetic profiles of white-fleshed pitaya (Selenicereus undatus) during maturation

Abstract

White-fleshed pitaya (Selenicereus undatus) is increasingly recognized as a functional fruit due to its antioxidant-rich composition, yet few studies have tracked changes in its bioactive profile during development. This study evaluated the temporal behavior of key bioactive compounds—total phenolics, β‑carotene, vitamin C, and antioxidant capacity (ABTS radical scavenging assay)—from 30 to 42 days after anthesis (DAA) and assessed the in silico pharmacokinetic potential of individual phenolic acids. Regression and derivative analyses revealed significant decreases in total phenolics (from 55 to 28 mg GAE·100 g⁻1 FM), vitamin C (from 76 to 22 mg·100 g⁻1 FM), and β‑carotene relative intensity (from ~85% to < 70%), with an inflection between 34 and 36 DAA. Antioxidant activity also declined during this period, reaching a minimum near 40 DAA. HPLC profiling showed that gallic acid (0.06 mg·100 g⁻1) and catechin (0.73 mg·100 g⁻1) were limited to early stages, whereas caffeic acid and vanillin persisted throughout fruit development, indicating higher chemical stability. Pearson correlation associated antioxidant activity mainly with gallic (R = 0.916) and chlorogenic (R = 0.844) acids. In silico pharmacokinetic predictions indicated favorable gastrointestinal absorption, drug-likeness, and synthetic accessibility for caffeic acid and vanillin, while other compounds were constrained by polarity or structural alerts. Overall, 30–34 DAA emerged as the optimal harvest window, maximizing the nutritional and functional potential of pitaya. These findings provide practical guidance for harvest planning and highlight the fruit’s potential in functional food development.