Effect of gamma irradiation on the quality (colour, firmness and total soluble solid) of tomato (Lycopersicon esculentum Mill.) stored at different temperature

A considerable amount of tomato is damaged after harvest every year (20-30% annually) which has impact on the total vegetable production in Bangladesh. Gamma irradiation doses of 250, 500 and 750 Gray (Gy) were analyzed compared to those of unirradiated ones on 1st, 8th and 13th day of irradiation stored at 4, 12 and 25°C to observe whether it could combat the loss. Radiation did not affect colour of tomato and it did not differ significantly with dose as well. However, storage time had effect on colour at 12 and 25°C at some aspect whereas no effect at 4°C in both irradiated and unirradiated tomatoes. Significant firmness was lost in irradiated tomatoes stored for 13 days at 4°C while no such significant differences in firmness was observed at 12 and 25°C. Immediate firmness loss was observed in irradiated tomatoes stored at 25°C and firmness decreased more in 500 and 750 Gy treated tomatoes than 250 Gy treated ones at 4 and 25°C whereas no such difference was observed between irradiation doses at 12°C. Radiation had no effect on percent sugar. Highest percentage of tomato loss was found at 25°C in both irradiated and unirradiated tomatoes but 750 Gy treated tomatoes showed promising result at all storage temperatures. Considering firmness loss,Total Soluble Solid (TSS) (%sugar) and damage during storage, a dose of 750 Gy and storage temperature 12°C stood out as ideal combination for BARI Hybrid-3 tomato in Bangladesh to combat annual post harvest loss.