Dynamic Changes in Pectin Composition, Flesh Firmness and Oxidoreductase Enzymes Across Different Stages of Fruit Development in Loquat Cultivars

Loquat fruits with a softer texture are susceptible to mechanical injuries and infection by pathogens during transportation and storage. Fruit ripening and softening are intricate processes, characterized by an interplay and coordination among metabolic pathways associated with biological functions. In this study, we aimed to elucidate the variation in the characteristics and potential determinants of cell wall dynamics throughout the developmental stages. Fruit firmness, pectin content, peroxidase and catalase activities in loquat fruit peel as well as pulp of three cultivars viz., ‘Golden Yellow’, ‘Saharanpur Special’ and ‘Tanaka’ at four fruit developmental stages from 60 days after fruit set (DAFS) to 92 DAFS (i.e., 60 DAFS [green stage], 75 DAFS [colour break stage], 85 DAFS [yellow stage] and 92 DAFS [orange stage]) were studied during 2 successive years, i.e., 2022 and 2023. The decrease in the firmness, pectin, peroxidase and catalase activities was positively correlated with the decline in the hardness during the fruit development. The maximum firmness, peroxidase and catalase enzymes during development were observed in cultivar ‘Tanaka’ at 92 DAFS (orange stage). Correlation analysis indicated complex interplay between biochemical components (such as pectin) and oxidoreductase enzymes (such as peroxidase and catalase) in regulating fruit firmness throughout the developmental stages of loquat cultivars. These findings will be helpful in providing systematic information on dynamic regulation of these processes, which is essential for improving fruit quality and developing strategies for enhancing post-harvest storage and transportation of loquat fruits.