Metabolism of Eugenia pyriformis cambess fruit during ripening and its implications for quality

Abstract

The objective of this study was to investigate the biochemical and physicochemical changes in Eugenia pyriformis Cambess (uvaia) fruits throughout three developmental stages (green, yellow-green, and yellow), with a focus on cell wall disintegration. Fruits were analyzed for size, color, pH, titratable acidity (TA), soluble solids (SS), total carotenoids, phenolics, antioxidant activity, firmness, soluble pectin, enzymatic activities (pectin methylesterase (PME), cellulase (Cx), β-galactosidase (β-Gal)), and cellular microstructure. Ripening was characterized by a color shift from deep green to golden yellow, increased pH, SS, and soluble pectin, reduced firmness and TA, and enhanced antioxidant activity associated with higher carotenoid content. β-Gal activity was sustained throughout ripening, with the highest levels observed at stage 1 compared to stages 2 and 3, which showed no significant difference Scanning electron microscopy revealed progressive cell wall degradation, especially of pectic polysaccharides, due to solubilization. Principal component analysis (PCA) explained 84.70% of total variance, with PC1 (72.98%) related to physicochemical and antioxidant traits, and PC2 (11.72%) associated with physical attributes. These findings demonstrate that uvaia ripening involves complex physiological, biochemical, and structural transformations that directly influence fruit quality and postharvest potential.