Postharvest Calcium Infiltration Delays Membrane Lipid Catabolism in Apple Fruit

Postharvest changes in membrane lipids of Ca 2+ -infiltrated apples ( Malus domestica Borkh. cv. Golden Delicious) have been evaluated. Calcium infiltration (2% or 4% w/v CaCl 2 ) improved fruit firmness retention over control (water-infiltrated) fruit following 6 months of 0 °C storage and after 7 subsequent days at 20 °C. During cold storage, total phospholipid (primarily phosphatidylcholine and phosphatidylethanolamine) and acylated steryl glycoside concentrations increased in Ca 2+ -infiltrated fruit but decreased in control fruit. Seven days following transfer from cold storage to 20 °C, total phospholipid concentration remained highest in fruit infiltrated with 4% CaCl 2 . Free sitosterol and steryl glycoside concentrations were generally increased with increasing infiltrated Ca 2+ concentration throughout the postharvest evaluation period. Greater conservation of specific membrane lipid components in the Ca 2+ -infiltrated fruit, both during and after low-temperature storage, may contribute to the well-known beneficial effects of Ca 2+ infiltration in maintaining apple quality.