Coordinated Regulation of Pigment Metabolism and Oxidative Pathways Governs Peel Pigmentation During Red Banana (Musa spp.) Fruit Development

Fruit growth and associated biochemical changes play a crucial role in determining peel colour in Red Banana, an important quality attribute influencing its marketability. The present study investigated stage dependent changes in fruit physical characteristics, pulp biochemical composition, peel pigments and enzyme activities from bunch emergence to harvest. Fruit growth followed a typical sigmoid pattern, with rapid increases in size and weight between 30 and 90 days after bunch emergence. Total soluble solids, total sugars and carotenoids in the pulp increased progressively during development, whereas titratable acidity, total starch and ascorbic acid showed an initial increase followed by a decline at later stages. Peel anthocyanin content decreased during advanced development (145.06 to 104.73 µg/g fresh weight), coinciding with chlorophyll degradation (2.65 to 0.91 mg/g fresh weight) and carotenoid accumulation (8.11 to 16.18 µg/g fresh weight), resulting in distinct colour transitions. The activities of peroxidase, polyphenol oxidase, β-glucosidase and laccase increased during mid-developmental stages, suggesting their possible involvement in pigment turnover. Principal component analysis (PCA) explained 92.58% of the total variation within the first two principal components and revealed a clear developmental separation of fruit stages, with later stages associated with fruit growth, carbohydrate accumulation and carotenoids, whereas intermediate stages were closely associated with anthocyanin and oxidative enzyme activities. These findings provide insights into the physiological and biochemical basis of peel pigmentation during fruit development in Red Banana.