Erhan İÇ, Özlem TURAN, Mine UYGUN, Turhan KÖSEOĞLU, Vasfiye BAŞBAYRAKTAR, Kadriye Yaprak KANTOĞLU
Food and Health - 2026;12(3):202-223
This study aimed to investigate the effects of gamma irradiation and storage conditions as a non-thermal and chemical-free technology on red tomatoes in order to reduce postharvest losses of a product that is economically important to the Turkish horticultural sector. Tomatoes were subjected to gamma irradiation at doses of 1 and 2 kGy and simultaneously stored at different temperatures (24 +/-2 dereceC and 4 +/-2 dereceC). The combined effects of low-dose gamma irradiation and storage temperature on the physicochemical, microbiological, and quality characteristics of red tomatoes were evaluated, with particular emphasis on the relationships between physical and chemical quality parameters and spoilage-related microbial load during storage. The results showed that the combined application of 1 kGy gamma irradiation and cold storage exhibited a synergistic effect in reducing weight loss and preserving colour attributes and total vitamin C stability. During storage at ambient temperature, physical parameters such as weight loss, firmness, and colour displayed similar trends between irradiated and control groups at the initial stages; however, statistically significant differences among groups emerged as storage time progressed (p<0.05). In terms of chemical parameters, control samples showed higher values at the beginning of storage. In contrast, tomatoes irradiated at 1 kGy maintained greater stability in total vitamin C content throughout storage at both temperatures. Microbiological analyses indicated that at the beginning of storage, total aerobic mesophilic bacteria (TAMB) and total yeast and mould (TYM) counts were <=10 CFU/g in samples stored at both temperatures. At ambient temperature, an increase in TYM counts was observed on day 9 in the control and 1 kGy-irradiated groups, while no increase was detected in the 2 kGy-irradiated group. Under cold storage conditions, microbial growth in both control and irradiated samples remained below <=10 CFU/g throughout the storage period. Overall, these findings demonstrate that combining postharvest cold storage with gamma irradiation is a promising strategy to reduce quality deterioration, suppress microbial growth, and preserve the nutritional integrity of tomatoes during storage.
