Improvement of shelf-life and microbiological quality of minimally processed refrigerated capsicum by gamma irradiation.

Shelf-life, microbiological and chemical quality of minimally processed capsicum subjected to radiation doses of 1, 2 and 3 kGy followed by storage at 5 degrees C and 10 degrees C were evaluated. Irradiation at an optimal dose of 2 kGy reduced the initial bacterial population by 2-3 log cycles and eliminated the coliforms Listeria and Yersinia. Chemical analysis revealed that the initial contents of ascorbic acid (127.7 mg/100 g), carotenoid (110 microg/100 g) and chlorophyll (7.75 mg/g) were reduced marginally by 5-10% with increasing radiation dose. However, during subsequent storage, up to 4 weeks, the temperature-dependent losses in vitamin C and chlorophyll content of irradiated samples were less compared with non-irradiated samples. The total carotenoid content of capsicum irradiated and stored for up to 2 weeks at 10 degrees C showed a similar trend. Thus, gamma irradiation at 2 kGy was found to improve both the hygienic quality and shelf-life without affecting the nutritional quality of minimally processed capsicum.