Application of the Edible Coating of Carboxy Methyl Cellulose/Pectin Composite Containing Humulus lupulus Extract on the Shelf Life of Fresh Cute Oranges at Cold Conditions

In this study, the fresh slices of orange were immersed in composite edible coatings including pectin (constant value, 1%), carboxymethyl cellulose (0, 1, 2%) and Humulus lupulus extract (0, 0.5 and 1%) and were kept in the refrigerator for 4, 9 and 14 days. Then, the characteristics of the samples were evaluated by qualitative tests including pH, acidity, antioxidant activity, total phenol, color properties (ΔE), vitamin C and total acceptance. In the following, the optimum conditions were determined based on the results of the tests and two samples were selected for validation tests. The optimum samples (including 1% pectin coating, 1.88% carboxymethyl cellulose (CMC) and 1% Humulus lupulus extract) and control (without edible coating) were kept in the refrigerator for 10 days and in addition to the above tests, two tests of texture analysis (penetration test) and Fourier-transform infrared spectroscopy (FT-IR analysis) were performed on them. The examination of the results showed that CMC and Humulus lupulusextracts prevented the oxidation of vitamin C. Composite edible coatings, especially in the high percentage of CMC, were able to maintain good vitamin C content in the fresh slices of orange. There was also a significant difference between the results of the control and optimum sample tests, indicating the positive effect of the edible coating used on the fresh slices of orange.