Physiological and biochemical changes relating to postharvest splitting of sweet cherries affected by calcium application in hydrocooling water

• Splitting-susceptible cherry cultivars absorbed Ca quickly in cold CaCl2 solutions.
• Enhanced Ca content reduced splitting potential by increasing splitting threshold.
• Fruit Ca was inversely correlated with soluble pectin release into surrounding water.
• EDTA or low pH depleted Ca from fruit and increased splitting potential.
• Adding CaCl2 in hydro-cooling water at appropriate rates reduced cherry splitting.

Hydrocooling sweet cherries shortly after harvest (4 h) and then transporting fruit in cold flume water during packing are used to maximize postharvest quality, but can cause fruit splitting. This study demonstrated that cherry fruit (two splitting-susceptible cultivars) absorbed Ca in a quadratic polynomial manner with increasing CaCl2 concentration from 0.2% to 2.0% in cold water (0 °C) for 5 min, but did not take up Cl. The enhanced tissue Ca content reduced splitting potential by decreasing fruit soluble pectin release and increasing the splitting threshold. In contrast, depleting Ca from fruit tissue by EDTA or low pH, increased soluble pectin release and splitting potential. In a simulated commercial procedure, hydrocooling cherry fruit in appropriate CaCl2 solutions (i.e., 0.2–0.5%) for 5 min and then passing the fruit in cold flume water for 15 min increased fruit firmness, retarded losses in ascorbic acid, titratable acidity, and skin color, and reduced splitting and decay following 4 weeks of cold storage.