The Effect of UV-C Irradiation on Rot Control and Postharvest Quality of Greenhouse Tomato (Solanum lycopersicum cv. Newton)

Tomato is one of the most important horticultural crops that is corruptible and susceptible to microbial contamination. In this study, the effect of UV-C at five different irradiation intensities (0, 3, 6, 9 and 12 kJ/m2) on rot control and postharvest quality of greenhouse tomato was investigated. Tomato (cv. Newton) fruits were harvested from a commercial greenhouse at vine-ripe stage and after treatment, were stored at 10 °C and relative humidity of 85-90%. Qualitative characteristics of the fruits such as decay rate, firmness, vitamin C, total soluble solids, titratable acidity, ripening index, weight loss and color (L*, a*, b*, Hue and Chroma) were evaluated after 7, 14, 21 and 28 days of cold storage. Results showed that vitamin C, firmness and color values were decreased; while weight loss percentage and decay rate were increased during the storage period. UV-C treatments did not have significant effect on traits of color, ripening index, weight loss percentage, firmness and pH. But the fruits treated with UV-C at 6 kJ/m2 dose had low decay rate as compared to control. The highest vitamin C content was obtained in treated fruits with 12 kJ/m2 of UV-C on twenty-first day of storage. Total soluble solids and titratable acidity were decreased in high doses of UV-C treatment. According to the results, it can be concluded that UV-C treatment of tomato fruits at vine-ripe stage, at its optimal doses, can reduce fruit decay and maintain or increase its antioxidant capacity, including vitamin C.