Journal of the Science of Food and Agriculture, 2025 (SCI-Expanded, Scopus)
BACKGROUND: Cacti, including pitaya (Hylocereus spp.), are rich in antioxidants that will undoubtedly gain importance under ongoing climate change as water resources decline. Yet the molecular basis linking composition to antioxidant function remains incompletely defined. We compared white-fleshed H. undatus and red-fleshed H. polyrhizus across physicochemical traits, integrating correlation, principal component analysis, and molecular docking to a human iron-regulatory protein (IRP1). RESULTS: White-fleshed fruits were larger and heavier (length 103.4 mm; width 60.2 mm; weight 204.7 g) than red-fleshed (71.9 mm; 54.5 mm; 126.3 g). Conversely, red-fleshed fruits showed higher total soluble solids (13.47 vs. 9.60 °Brix), total phenolics (379.7 vs. 183.0 mg L−1), total flavonoids (303.7 vs. 147.3 mg L−1), and antioxidant activity (52.3% vs. 30.0%). Organic acids and phenolics differed by species (e.g., higher citric acid in red; higher malic acid in white). Correlations indicated that greater soluble sugars were associated with higher phenolic accumulation, consistent with the elevated antioxidant capacity of red-fleshed fruit. The first two principal components explained 83.3% of the total variance (PC1 = 68.8%, PC2 = 14.5%) and separated samples along size/°Brix versus phenolic/ antioxidant axes. Docking predicted favorable binding of major acids and phenolics to IRP1, suggesting plausible antioxidant mechanisms. CONCLUSION: Findings support species-specific use, with red-fleshed H. polyrhizus serving as a nutrient-dense source of antioxidant compounds, while white-fleshed H. undatus offers advantageous pomological traits. Integrating compositional profiling with multivariate analysis and docking provides mechanistic context and practical implications for breeding, climate-resilient cultivation, and industrial applications. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.