Effect of carboxymethyl cellulose coating enriched with clove oil on postharvest quality of 'Xinyu' mandarin oranges
Introduction. Attempts to exploit natural preservatives to control postharvest diseases as an alternative technology to synthetic fungicides in citrus fruit have been drawing much attention. Materials and methods. The combined effects of carboxymethyl cellulose (CMC) coating and/or clove oil on the qualitative properties of cold stored 'Xinyu' mandarin oranges stored at 5 degC for 120 days were investigated. Results and discussion. The results showed that the addition of clove oil as an antifungal component to the CMC coating had a good effect on the inhibitory growth of fungal decay, and the coating treatments significantly decreased the decay rate and weight loss, as well as the maleic dialdehyde (MDA) concentration compared with control samples. The clove oil carboxymethyl cellulose (CO CMC) coating significantly maintained commercial quality and inhibited respiration. Meanwhile, the results showed that the activities of superoxide dismutase (SOD) catalase (CAT) polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) in fruit treated with CO CMC coating were higher than in those treated with CMC coating and control samples. Conclusion. The CO CMC coating has good potential for application as an alternative to synthetic fungicides for improving postharvest quality and prolonging the shelf life of 'Xinyu' mandarin oranges during cold storage.