IMPACT BRUISE RESISTANCE COMPARISON AMONG PEACH CULTIVARS

Impact testing was used to assess the variables related to bruise resistance for four peach [Prunus persica (L.) Batsch] cultivars. The effects of cultivar, ripeness, drop height, and firmness on fruit bruise incidence, bruise volume, respiration, and ethylene evolution rates of freshly harvested peaches were determined. The impact variables peak impact force, contact time, absorbed energy, and percent absorbed energy were measured at three stages of fruit ripeness and at three fruit drop heights. Each of the impact variables changed with fruit ripeness. Cultivars differed in their characteristic response to impact. Fruit impact, under the low to moderate impact energies used, had negligible effects on fruit respiration and ethylene production for the cultivars studied. Bruise incidence and volume increased with drop height and especially with advancing stage of ripeness. Under conditions we used, peach fruit bruise severity could be determined by either bruise incidence in or bruise volume of mesocarp tissue.