363 UV-C Irradiation Reduces Decay and Improves Quality of Fresh-cut Squash

Abstract

Exposure of fresh-cut zucchini squash (Cucurbita pepo L., cv. Tigress) to ultraviolet-C (UV-C) irradiation for 1, 10, or 20 min significantly reduced microbial counts and severity of decay during subsequent storage at 5 or 10 °C. However, the respiration rate and ethylene production of the slices were not affected by the UV-C treatments. Slight UV-C damage (reddish brown discoloration) was detected on the surface of 10- and 20-min treated slices after 12 days of storage at 10 °C. Slices stored at 5 °C did not show UV-C damage. Chilling injury was not observed until after 20 days of storage at 5 °C. The symptoms of chilling injury appeared as dried sunken brown spots on the surface of cortex tissue. UV-C treatments did not affect the degree of chilling injury during storage at 5 C. The storage quality of fresh-cut zucchini squash was improved by UV-C exposure primarily because of the retardation of microbial growth and reduction of decay. The influence of UV-C irradiation on sugar and organic acid contents of the fresh-cut zucchini squash will also be discussed.