Decontamination of unpackaged and vacuum-packaged boneless chicken breast with pulsed ultraviolet light

The effectiveness of pulsed UV light on the microbial load of boneless chicken breast was investigated. Unpackaged and vacuum-packaged samples inoculated with an antibiotic-resistant strain of Salmonella Typhimurium on the top surfaces were treated with pulsed UV light for 5, 15, 30, 45, and 60 s at 5, 8, and 13 cm distance from the quartz window in the pulsed UV light chamber. The log₁₀ reductions of Salmonella (cfu/cm²) on unpackaged samples varied from 1.2 to 2.4 after a 5-s treatment at 13 cm and a 60-s treatment at 5 cm, respectively. The log₁₀ reductions on vacuum-packaged samples varied from 0.8 to 2.4 after the 5-s treatment at 13 cm and the 60-s treatment at 5 cm, respectively. The optimum treatment conditions were determined to be 5 cm-15 s for unpackaged samples and 5 cm-30 s for vacuum-packaged samples, both of which resulted in about 2 log₁₀ reduction (~99%). The total energy and temperaturesof samples increased with longer treatment time and shorter distance from the quartz window in the ulsed UV light chamber. The changes in chemical quality and color of samples were determined after mild (at 13 cm for 5 s), moderate (at 8 cm for 30 s), and extreme (at 5 cm for 60 s) treatments. Neither malonaldehyde contents nor color parameters changed significantly (P > 0.05) after mild and moderate treatments. Mechanical properties of the packaging material were analyzed before and after pulsed UV light treatments. The elastic modulus at both along-machine and perpendicular-tomachine direction and yield strength at perpendicularto- machine direction changed significantly (P < 0.05) after extreme treatment. Overall, these results clearly indicate that pulsed UV light has a potential to be used for decontamination of unpackaged and vacuumpackaged poultry.