This study aimed to evaluate the effect of various levels of gamma irradiation on the physico-chemical composition of fresh tomatoes. Tomato samples were irradiated in a Co-60 gamma irradiator and maintained at 25 °C ± 2 storage conditions. The experiment was designed with five treatments of radiation dose (0, 0.5, 0.75 1.0, 1.5, and 2 kGy). Before irradiation, the initial composition of physical-chemical properties were analysed (pH, TSS, TTA, moisture, Vitamin-C, lycopene, and ?-carotene). The repeated analysis of the physico-chemical properties of tomato fruits was done after 7, 14, 21, and 28 days. The results showed a significant difference between non-irradiated and irradiated tomatoes in Vitamin-C and lycopene content. No significant differences for pH, moisture, TSS, acidity and ?-carotene were noted. The observation shows that vitamin C in tomatoes is affected by irradiation dose with respect to storage time, while maintaining most of the physico-chemical composition, hence the technology of radiation was effective in preserving the nutritional composition of tomatoes.

Keywords: Physico-chemical analysis, Gamma irradiation, Storage period, Tomato