Impact of radiation processing on quality during storage and post-refrigeration decay of plum (Prunus domestica L.) cv. Santaroza

Abstract Gamma irradiation treatment was tested for maintaining storage quality and extending the shelf life of plum fruit. Matured green plums were irradiated in the dose range of 0.2–1.5 kGy and stored under ambient (temperature 25±2 °C, RH 70%) and refrigerated (temperature 3±1 °C, RH 80%) conditions. Studies revealed that irradiation treatment significantly ( p ≤0.05) maintained the storage quality of plum fruit under ambient as well as refrigerated conditions. Positive correlations ( r= 0.88) existed between the irradiation doses and firmness retention under both the storage conditions. In samples irradiated at 1.0 kGy, 1.2 kGy and 1.5 kGy, no microbial load was detected up to 8 and 12 days of ambient storage. Dose range of 1.2–1.5 kGy significantly inhibited the decaying of plums up to 16 days of ambient storage. Irradiation in combination with refrigeration prevented the decaying of plums up to 35 days as against the 12.5% decay in un-irradiated control samples. Irradiation dose of 1.2–1.5 kGy also gave an extension of 8 days during additional ambient storage of the plums at 25±2 °C, RH 70% following 35 days of refrigeration.