FACTORS INFLUENCING MECHANICAL-PROPERTIES AND BRUISE SUSCEPTIBILITY OF APPLES AND PEARS

Fruit turgidity and firmness have been shown to influence impact bruise susceptibility in apples and pears. Analysis of impact response showed that stresses in the tissues were higher in turgid fruit, so they were more susceptible to bruising. Turgidity changes seemed to be the cause of the lower susceptibility of fruits to damage after storage. The physical parameter ''deformation at skin puncture'' was shown to indicate fruit turgidity changes and was found to be related to bruise susceptibility. The influence of fruit turgidity was greater than that of firmness. Fruits picked early were less susceptible to bruising than those picked later.