Physiological and Biochemical Responses in Cold-Stored Citrus Fruits to Carboxymethyl Cellulose Coating Containing Ethanol Extract of Impatiens balsamina L. Stems

Abstract

Abstract A novel edible coating based on carboxymethyl cellulose (1.5%, CMC) containing ethanol extract of Impatiens balsamina L. stems, 0.07% citric acid, 0.5% sucrose ester, 1.0% calcium propionate and 0.5% glycerol was applied to “Xinyu” tangerines to delay their ripening and prolong postharvest life during storage at 5C for 100 days. The addition of IB extract as antifungal components in the CMC coating had an inhibitory effect on mold growth, and the coated treatments significantly decreased decay rate and weight loss, maintained commercial quality and enhanced the activities of antioxidant and defense-related enzymes compared with the uncoated control group. The results suggested that by applying the complex coating, we can delay the ripening and prolong the postharvest life of “Xinyu” tangerines. Practical Applications Edible coatings could be an effective technology for obstructing pathogenic infection and delaying the ripening process of fruits and vegetables during the postharvest storage period. The effectiveness of an edible coating based on 1.5% CMC coating containing IB extract and other film-forming additives, in comparison with CMC coating without IB extract, was applied in “Xinyu” tangerines in order to reduce the rate of decay and maintain the nutritional quality of fruit during postharvest storage. The results showed that complex coating was able to provide a barrier to the pathogen and gas by reducing decay rate and weight loss. Meanwhile, the degradation of the nutritional quality of “Xinyu” tangerines was significantly delayed. The activities of SOD, CAT, POD, PAL and GLU were much higher in the complex coating treatment than in CMC coating alone and the control group. Our results suggest that the complex coating could be explored as a novel and potentially natural edible coating for preserving “Xinyu” tangerines.