the effect of chitosan-based nano-emulsion coating on extending the shelf life of apple var. golab kohanz

the effects of a nano-emulsion chitosan-based coating on enhancing the shelf-life and quality of golab kohanz apples were studied. the nano-emulsion coating containing chitosan with a concentration of 2000 ppm was applied for coating of golab kohanz apples. coated and uncoated apples were packed in normal packaging cardboards and kept at 2 ± 1 °c with a relative humidity within 80-85%. flesh firmness, the activity of polyphenol oxidase, flesh and skin colors, the rate of respiration based on the level of co2 produced and the sensory characteristics of the coated vs. uncoated apples were recorded during a ten week of storage period at some specified intervals of one week. the results indicated that the coatings had no significant effect on flesh firmness and sensory characteristics of the apples, while the respiration rate of the coated apples decreased up to 50% with the coating lowering the respiration peak significantly. the polyphenol oxidase activity and the browning of the flesh increased significantly in uncoated apples following the respiration peak. overall, results showed that the nano-emulsion chitosan-based coating can help increase the storage life of the apple.