Management of Postharvest Fruit Softening and Quality of Peach by Calcium Chloride
Sami Ullah1, Ahmad Sattar Khan2, Kashif Razzaq1, Ishtiaq Ahmad Rajwana1, Muhammad Amin1, Hafiz Nazar Faried1, Gulzar Akhtar1
1MNS-University of Agriculture, Dept. of Horticulture, Pakistan
Application of calcium chloride (CaCl2) has been reported to delay ripening of fruit. Hence, a study was conducted to examine the effects of postharvest CaCl2 application on peach fruit (Prunus persica L. Batsch. cv. ‘Flordaking’) softening and quality characteristics during shelf life and cold storage. The fruit after harvest were dipped for 5 min in aqueous solutions containing different concentration of CaCl2 viz. 0, 2%, 4% or 6% + Tween 20® (1 g L-1). The treated fruit were kept at ambient conditions (25 ± 2 °C; RH 60-65%), under cold storage (0 ± 1 °C; RH 80-85%) and at ripening following by cold storage. The fruit were evaluated for physiological (ethylene production, respiration rate, weight loss, fruit firmness); biochemical fruit quality characteristics;, fruit firmness, activities of cell wall hydrolyzing enzymes and antioxidative during ripening, under cold storage and at ripening followed by cold storage as well. Postharvest application of 6% CaCl2 significantly reduced ethylene production and respiration rate during ripening, at ambient and following cold storage. Reduced fruit softening and activities of fruit softening enzymes including PE, EGase, endo-PG and exo-PG were exhibited by 6% CaCl2-treated fruit as compared with untreated fruit. Lowest fruit weight loss, SSC, and highest fruit firmness were observed in 6% CaCl2-treated peach fruit than untreated fruit during ripening, after storage and at ripening following cold storage. Application of 6% CaCl2 significantly enhanced the antioxidant scavenging activity (ASA), total phenolic contents (TPC) and activities of antioxidative enzymes including CAT, POD and SOD than untreated peach fruit during ripening, under cold storage and at ripening followed by cold storage. Although application of 6% CaCl2 significantly reduced ethylene production, fruit softening, fruit softening enzymes activities and increased anti-oxidative activity, peach fruit treated with higher concentration of CaCl2 (6%) exhibited skin discolouration and superficial pitting during shelf life ripening following by cold storage. Keeping the above deleterious effects of higher dose, 4% CaCl2 was more preferable to maintain fruit softening and quality of peach fruit during ripening and cold storage.
Keywords: Antioxidants, fruit ripening, low temperature storage
Contact Address: Sami Ullah, MNS-University of Agriculture, Dept. of Horticulture, 60000 Multan, Pakistan, e-mail: sami.ullah1mnsuam.edu.pk