TRANSACTIONS OF THE ASABE, cilt.54, sa.3, ss.993-1000, 2011 (SCI-Expanded)
Pulsed UV light is a novel technology that is designed to inactivate microorganisms on surfaces in very short times. In this study, a pilot-scale pulsed UV light system was designed, built, and evaluated for its effectiveness on the microbial load of whole chicken carcasses. The pulsed UV light system consists of four 40.64 cm (16 in.) lamp housings, facing each other in series, and a linear rail mounted along the midpoint of the chamber ceiling. Each chicken surface was sprayed with Escherichia coli K12 inoculum and treated at approximately 5 cm from the quartz window of the lamp housing on each side. Treatment times of 30, 45, 60, 90, 120, and 180 s were selected, based on the time each chicken would spend between one set of lamps. The log(10) reductions ranged from 0.87 to 1.43 CFU mL(-1) rinse solution after 30 and 180 s treatments, which correspond to conveyor velocities of 78 and 13 cm min(-1), respectively. Energy levels for the lamps ranged from 0.24 to 0.25 J pulse(-1) cm(-2). Sample temperatures increased significantly (p < 0.05) with longer treatment times, and the temperatures ranged from 11.1 degrees C to 44.1 degrees C. CIELAB color parameters of carcasses after 45, 90, and 180 s treatments were determined. A significant (p < 0.05) decrease in L* values and increase in b* values was observed after 90 and 180 s treatments, while a* values did not change significantly (p > 0.05) after treatments. The optimum treatment time was identified as 45 s, which resulted in similar to 1 log(10) reduction (90% reduction). Overall, the pilot-scale pulsed UV light system was successfully designed and tested to demonstrate the potential of pulsed UV light treatment to decontaminate the surfaces of chicken carcasses without the use of chemicals.