Effect of gaseous ozone on microbial inactivation and sensory of flaked red peppers

Flaked red peppers inoculated with Escherichia coli, Bacillus cereus and B. cereus spores were exposed to gaseous ozone at 20 °C and 70% relative humidity (RH). Ozone concentrations of 0.1, 0.5 and 1.0 ppm up to 360 min were used to reduce E. coli and B. cereus, whereas 1.0, 5.0, 7.0 and 9.0 ppm ozone concentrations for 360 min were used to treat B. cereus spores. When flaked red peppers were treated with 1.0 ppm ozone concentration for 360 min, B. cereus and E. coli counts were decreased by 1.5 and 2.0 log numbers, respectively. Bacillus cereus spores were reduced by 1.5 log numbers at ozone concentrations of 7.0 ppm or above for 360 min. There were slight changes in flavour, appearance and overall palatability of flaked red peppers treated with ozone between 5.0 and 9.0 ppm. Ozone concentration (1.0 ppm) for 360 min can be used to decrease E. coli and B. cereus, whereas ozone concentrations >=5.0 ppm can be used to reduce B. cereus spores.