Why are fruits considered highly perishable after harvest?

Fruits are considered highly perishable because they remain living biological entities after harvest, continuing to perform vital metabolic functions such as respiration and transpiration. Because they are detached from the plant, they must rely solely on their own limited internal reserves of moisture and nutrients to sustain these processes.1

The transition from maturation to ripening is driven by enzymes that catalyze complex chemical changes, such as the degradation of cell walls, which leads to tissue softening and eventual breakdown. This process of senescence marks the shift from synthesis to degradation, making the fruit increasingly susceptible to microorganisms like bacteria, yeasts, and molds. Furthermore, the rate of these chemical changes is highly sensitive to ambient temperature; higher temperatures accelerate respiration, significantly shortening the fruit's postharvest life.2341