Effect of γ-Irradiation Combined with Washing and Waxing Treatment on Physicochemical Properties, Vitamin C, and Organoleptic Quality of Citrus clementina Hort. Ex. Tanaka

To enhance the shelf life of a late variety of Moroccan Citrus clementina (Nour), ionizing treatments were applied at 0.3 kGy, as well as washing (cold water) and waxing treatments. It has been found that, despite the irradiation treatment, the washing and waxing treatment do not improve the quality of C. clementina, but rather result in yellower peels, peel injury, and reductions of vitamin C content, acidity, and soluble solids. However, γ-irradiation alone enhanced significantly (p ≤ 0.05) the level of vitamin C and the total phenolic content and maintained the color of the C. clementina during the entire storage period (49 days at 3 ± 1 °C and 84% relative humidity). Finally, sensory evaluation further confirmed the beneficial effect of γ-irradiation. Irradiated clementines were found to be sweeter. Also, the sensorial score of irradiated (I) and washed, waxed, and un-irradiated (LC) fruits was maintained over 7 days during 21 days as compared to 14 days for unwashed, unwaxed, and un-irradiated (C) and for washed, waxed, and irradiated (LCI) fruits. Keywords: Citrus clementina Hort. ex.Tanaka; γ-irradiation; cold water and waxing treatment