Effects of Chitosan Coating on Disease Resistance and Storage Quality of Navel Orange Fruit

In order to understand how chitosan affects disease resistance and quality of navel orange fruit(Citrussinensis L.osbeck) cv.Newhall after harvest,navel orange fruits were treated with 2 g chitosan /100 g solution for 1 min,and some fruits were taken out,dried naturally and inoculated with Penicillium italicum.Then,the fruits were stored at 20 ℃ and 85% to 95% RH.Results indicated that the disease incidence and the lesion diameter in the chitosan-treated fruit are 72.72% and 90.19%,lower than those in control fruit on the 18th day of incubation.The chitosan treatment maintains the soluble protein content,total phenolic and flavonoid level of navel orange fruit,which maybe involve in the maintenance of disease resistance of navel orange fruit.Treating navel orange fruit with 2 g chitosan /100 g solution effectively reduces the decrease in the content of ascorbic acid(AsA),water,titratable acidity(TA) and total soluble solids(TSS).These results suggested that the treatment with chitosan coating enhances the disease resistance and exhibits a potential for storage life extension of the navel orange fruit stored at ambient temperature.