# Comparative analysis of pomological and phytochemical characteristics in white‐ and red‐fleshed pitaya ( Hylocereus spp.), with molecular docking insights into key bioactive compounds

## TL;DR

This study compares white and red-fleshed pitaya fruits, finding that red-fleshed varieties have higher antioxidant compounds and nutrients, while white-fleshed ones are larger and heavier.

## Contribution

The study integrates phytochemical analysis, multivariate statistics, and molecular docking to reveal antioxidant mechanisms and practical applications in pitaya species.

## Key findings

- Red-fleshed H. polyrhizus fruits have higher total phenolics, flavonoids, and antioxidant activity compared to white-fleshed H. undatus.
- Molecular docking suggests that key acids and phenolics from pitaya bind to a human iron-regulatory protein, potentially explaining antioxidant effects.
- Principal component analysis separated the fruits along size/°Brix versus phenolic/antioxidant axes, explaining 83.3% of the variance.

## Abstract

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).

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.

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.