Research Progress on the Mechanism of Fruit Ripening and Softening

The softening and ripening of fruits have always been a focal point in postharvest preservation and storage. Since the composition of plant cell walls is closely related to firmness, changes in fruit texture and softening are associated with alterations in cell wall components. Numerous studies have shown that fruit ripening and softening are closely linked to changes and degradation in cell wall structure and polysaccharide substances, while modifications in cell wall structure and composition are related to certain cell wall-degrading enzymes. These enzymes participate in different stages of fruit softening, leading to varying outcomes. The early-stage softening primarily involves changes in cellulose microfibrils, intercellular adhesion, xylan, starch, and other factors, whereas late-stage softening is associated with the disintegration of the cell wall. This paper aims to generalize the mechanism of fruit softening and improve fruit quality by reviewing the changes in cell wall structure and composition during fruit ripening and softening, as well as the effects of cell wall-degrading enzymes and expression of related genes. The findings provide a theoretical basis for enhancing fruit quality, storage performance, and molecular breeding.