Effect of chitosan and oOrtho phenyl Phenol coating on shelf life of Thompson orange

Recently, Using natural coatings have been replaced with chemical coatings by most consumers all over the world. In this research, some qualitative properties of Thomson orange were evaluated using Chitosan edible coating (at 0.5, 1 and 2 % concentrations) and chemical coating of fungicide (Ortho Phenyl Phenol) was compared to uncoated samples during three months of storage. Orange samples were kept in cold storage at temperature of 6°C with 85-90% relative humidity. Also pH, titrable acidity of orange juice and weight loss percentage were measured during storage. The results showed that chitosan coating with 2% concentration has reduced weight loss of orange juice compared to other coatings; furthermore, having higher pH than the rest of samples, it has enhanced fruit resistance against fungal attacks. Overall, it has also preserved the fruit quality during storage time.