Effect of nanochitosan based coating on climacteric behavior and postharvest shelf-life extension of apple cv. Golab Kohanz

• Apple cv. Golab Kohanz is a highly perishable apple variety.
• Coating of the apple with 0.5% nanochitosan lowered the maximum ethylene production.
• This coating markedly eliminated the climacteric respiration peak.
• The coating slowed down the natural fruit ripening.
• Nanochitosan coating enhanced the quality and storage life of the apple.

The effect of nanochitosan-based coating on the quality and storage life of apple cv. Golab Kohanz was studied. Fresh fruits were coated with nanochitosan emulsion (less than 100 nm) with two chitosan concentrations of 0.2 and 0.5%. The fruits were kept at 1 ± 1 °C and relative humidity of 85–90% for nine weeks. Respiration rate based on the amount of carbon dioxide (CO2) produced, weight loss, enzyme activities, color characteristics, ethylene production, firmness of the coated and uncoated apples were measured during nine weeks of storage at specified intervals (once a week). The results showed that coating significantly reduced weight loss, respiration rate, ethylene production and peroxidase activity of the samples compared with the control. Coating had significant effect on polyphenol oxidase activity, slowed down softening process and improved the flesh color after the climacteric peak. Nanochitosan coating with 0.5% chitosan concentration significantly extended the quality and prevented the weight loss of the fruits, over the entire storage period. These findings confirmed the potential benefits of applying nanochitosan coatings to extend the shelf life and maintain the quality of this highly sensitive apple. The results showed that nanochitosan coating is particularly effective after the climacteric period.