Combined Treatment with Hydrogen Peroxide and Ultra-violet Irradiation to Reduce Microbial Contamination Levels in...

A treatment combining hydrogen peroxide and ultra-violet (UV-C) irradiation was assessed for reduction of microbial contamination in pre-formed food packaging cartons. There was a synergistic effect between low concentrations (0 - 5% wt/vol) of hydrogen peroxide and UV-C irradiation (10 s) on spores of Bacillus subtilis , the maximum lethality occurring between 0.5 and 1% peroxide. A combined treatment using 1% hydrogen peroxide and 10 s of UV-C irradiation was also effective against a variety of other organisms (spores and vegetative cells). The efficiency of the treatment was dependent on the type of inner surface of the carton. A greater lethal effect was obtained against B. subtilis spores in polyethylene-lined cartons than in aluminium/polyethylene laminate-lined cartons (5.1 and 3.5 decimal reductions in numbers respectively, using a combined treatment with 1% peroxide and 10 s of UV-C).