Postharvest Calcium Infiltration Delays Membrane Lipid Catabolism in Apple Fruit

Abstract

Postharvest changes in membrane lipids of Ca2+-infiltrated apples (Malus domestica Borkh. cv. Golden Delicious) have been evaluated. Calcium infiltration (2% or 4% w/v CaCl2) 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 Ca2+-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% CaCl2. Free sitosterol and steryl glycoside concentrations were generally increased with increasing infiltrated Ca2+ concentration throughout the postharvest evaluation period. Greater conservation of specific membrane lipid components in the Ca2+-infiltrated fruit, both during and after low-temperature storage, may contribute to the well-known beneficial effects of Ca2+ infiltration in maintaining apple quality. Keywords: Plant senescence; ripening; glycerolipids; steryl lipids; Malus domestica Borkh.