Effect of coating and protection treatments on the storability of Page and Unshio mandarin varieties in cold storage

The aim of this research was increasing quality and storability of Unshio and Page mandarin fruits. Therefore, harvested fruits were invited to 5 groups (120 fruits) with three replications (40 fruits per replicate). The treatments were including: Britex Ti wax (18 wt% wax, 0.2% w/w Imazalil, 0.5 wt% thiabendazole), polyethylene pack (25mm×35cm, 0.01mm thick), thiabendazole fungicide (Tecto 60), Polyethylene pack with Tecto 60 and control. The treated fruits were kept for 60 days (Unshio) and 40 days (page) in cool storage (5°C and 85% RH). Six fruits were randomly selected from each treatment every 20 days intervals, and then measured some quality indices. The results showed that polyethylene pack alone or in combination with fungicide prevented weight loss, kept the peel thickness and reduced the juice percentage, TI and TSS. Also, TSS/TA and pH were significantly increased during storage in both cultivars. The amount of peel lightness decreased during storage. Peel lightness in page fruits which were treated by wax and fungicide was 60 (mean 58). It was significantly less than other treatments (mean 61). The amount of a* increased in Unshio (from 14.77 to 19.83) and Page during storage, but in Page fruits that were covered by polyethylene pack was the highest (34.9) at the end of 40 days storage period. The range of hue angle in Unshio was between 65.54 (wax) and 92.61 (control) at the end of storage. Page fruits had the higher hue angle when treated by polyethylene pack alone (67.25), or in combination with Tecto 60 (65.79). According to sensory analysis, the fruits were treated by Tecto 60 and covered by a polyethylene pack, had significantly the better appearance during 60 (Unshio) and 40 (page) days after beginning of storage.