Apple cv. Golab Kohanz is a sensitive and highly perishable apple variety with a very limited storage life. Coating of this fruit using nanochitosan emulsion significantly enhanced the quality and storage life of the apple. These coatings were used as a thin layer on the surface of the fruit to prevent products from transferring moisture, gases, and dissolved substances. On the other hand, they reduced the respiratory rate of the products and acted as modified atmosphere packaging. By reducing the size of chitosan and applying nanochitosan coating, the effective concentration of chitosan decreased considerably to 0.5% as compared to those effective concentrations suggested in previous studies for coating different fresh horticultural products (Gao et al., 2013; Han et al., 2014; Jiang & Li, 2001). Nanochitosan coating with 0.5% chitosan markedly eliminated the climacteric respiration peak by subsequently lowering the maximum ethylene production to approximately 33%. The coating positively controlled the enzymatic activities, improved the color quality of the fruit, slowed down the fruit softening and declined the weight loss up to 2.5 times over a nine
week period of storage.
The overall results showed that nanochitosan coatings slowed down the natural fruit ripening and improved the quality and postharvest storage-life of the apple, specifically after the climacteric period.