Enhancing Shelf-life of Fresh-cut Carrot and Cauliflower Floret with Combined Ozone and Ultraviolet-C Radiation Treatment

Abstract

The effects of ozone and ultraviolet (UV-C) radiation on the quality parameters and microbiology of fresh-cut carrot and cauliflower were investigated. Carrot slices (3 mm thickness) and cauliflower florets were treated with ozonated water (1 ppm) for 10 min and also with sodium hypochlorite solution (100 ppm available chlorine) for comparison. The treated cut vegetables were sealed in polypropylene films and stored at a temperature of 5- 7 °C. In another group, the ozone treated and packed cut-vegetables were subsequently exposed under UV-C radiation for 5 minutes. Microbiological counts (total bacterial count and total fungal count), firmness, colour, TSS, pH and decay rate of products were determined just after treatment, and at regular intervals during storage. The population of microorganisms in the samples treated with both ozone and UV-C was lowest compared to that of other treatment samples. Both bacterial and fungal population of carrot and cauliflower samples with the ozone + UV-C treatment were less than 5 log CFU g-1 initially, and kept the lowest level among all treatments during their storage. Ozone and UV-C radiation significantly inhibited the decay rate and decrease in firmness and TSS, and increased the colour values in the fresh-cut carrots and cauliflowers.