Gamma irradiation treatment of minimally processed kiwi fruit to maintain physicochemical quality and prevent microbial proliferation during refrigerated storage

Abstract

Mature kiwi after minimal processing were treated with 0.5–2.0 kGy gamma irradiation to monitor changes in quality parameters under refrigerated conditions (3 ± 1°C, RH 85%) for 16 days. The results revealed that treatment of 2.0 kGy proved helpful in delaying onset of surface browning, reducing the polyphenol oxidase activity and preserving the original color of samples till 16 days. Dose dependent decrease in polyphenol oxidase activity and surface browning was observed in kiwi samples. Control samples were almost devoid of chlorophyll after 12 days; whereas 2.0 kGy samples, showed decrease of 29.6% in chlorophyll after 16 days. Dose of 2.0 kGy significantly prevented the proliferation of microbial load and resulted in 5.7 log reduction in yeast and mold count and 6.0 log reductions in bacterial count of kiwi samples after the end of 16 days of storage; therefore, satisfying food safety concerns of ready to eat kiwi fruit. Practical applications Increasing demand for ready to eat, convenience chemical free and health promoting foods associated with limited shelf-life has forced the food scientists to search for new technologies. Extending shelf-life and maintaining both nutritional as well as microbial quality has beneficial implications on industry and consumers. Present investigation showed that radiation processing of minimally processed kiwi offers a promising alternative to chemicals to delay the onset of browning besides maintaining other quality attributes and thus ensuring consumer safety and satisfaction.