Effects of Methylcellulose-wax as combined coating materials on physico-chemical and sensorial characteristics of Thomson navel orange

In this study, effects of coating materials: methylcellulose-wax; and wax on physic-chemical and sensorial characteristics of Thomson navel orange at 8 °C were evaluated. Weight loss, vitamin C, total soluble solid (TSS), acidity (TA), and sensory evaluation every two weeks for 16 weeks of storage were analyzed. Fruits were coated with commercial wax or composite methylcellulose-wax (MC, 9: 10, w/w) using immersion treatment. Uncoated fruits were used as control ones. This research was performed using a factorial experimental model in a completely randomized design with 5 replications at an accuracy rate of 95%. Coatings by wax were the most effective in reducing weight loss. Fruits coated with composite coating materials, had the highest level of vitamin C in comparison with other samples. TSS and TA of all samples decreased during storage, while the TSS / TA ratio increased in all treatments. Fruits treated with methylcellulose-wax within 10 and 16 weeks of storage preserved TA values more than other treatments. The results of sensory evaluation showed that the least desirable flavor was related to 8 weeks after storage. Within 10 and 16 weeks, the highest off-flavor was related to the fruits coated by wax Freshness of fruits decreased during storage. No significant difference was observed between the fruits coated by MC-Wax and wax.