EFFECT OF GAMMA-IRRADIATION COMBINED WITH HOT-WATER TREATMENT ON THE PHYSICOCHEMICAL PROPERTIES, VITAMIN-C CONTENT AND ORGANOLEPTIC QUALITYOF CLEMENTINES

Clementines (Marisol) from Spain were irradiated with gamma rays at do ses of 0.3 and 0.5 kGy, with and without a hot water treatment (53-deg rees-C-5 min) and stored at 17-degrees-C and 46% relative humidity for 3 weeks. They were compared to unirradiated control (C) clementines f or shelf-life, texture, color, pH, degree-Brix, vitamin C content and organoleptic quality. Irradiated clementines were found to be less fir m than C fruits. Minor changes occurred in the pH of control and irrad iated clementines during storage. The total soluble solids content (de gree-Brix) decreased for the irradiated clementines but little differe nce was noted between the hot water treated clementines irradiated at a dose of 0.5 kGy and the control. The vitamin C content of treated cl ementines was also higher than that of the C fruits. Results in sensor y evaluation also pointed out that the organoleptic quality of the irr adiated clementines was maintained during storage. However, the hot wa ter treated irradiated fruits reached the limit of acceptability after two weeks of storage and were judged unacceptable from the third one. This study demonstrated clearly that irradiation at doses of 0.3 and 0.5 kGy, as an alternative process to quarantine treatment, preserved the quality of clementines but that the hot water treatment combined w ith irradiation was detrimental to their shelf-life under the chosen e xperimental conditions.