A Comparison of Chitosan-Clay and Fungicide-Wax Coatings on some Quality Properties of Thomson Navel Orange during Storage

Most consumers prefer natural coatings to the chemical ones to act as an enhancement of storage quality of fruits. In this research, quality of Thomson oranges coated with chitosan-clay nano composite edible coating plus fungicide-wax chemical coating was compared with a non-coated sample during storage for a period of 3 months through a factorial design (3×4). Orange samples were kept in a cold storage at 5oC temperature and 85-90% of relative humidity. The pH, titratable acidity of orange juice, weight loss percentage, peel shear and fracture forces as well as the coefficient of elasticity were assayed during storage. Results indicated significant differences among different coatings on all the measured dependent variables except on peel shear force (p<0.01). In addition, storage duration significantly affected weight loss, fruit peel cutting and fracture forces (p<0.01). Also fruits coated with Chitosan-clay showed reduction in weight loss, increase in pH, the highest fracture force as well as the coefficient of elasticity as compared with the control samples. Therefore, it is concluded that the coating increased fruit resistance to fungal diseases, retained inner texture strength and prevented the decrease in fruit quality.