This study evaluated the efficacy of three pulsed light systems (1.8, 3 and 100 Hz) for inactivation of Salmonella Montevideo on the surface... Show moreThis study evaluated the efficacy of three pulsed light systems (1.8, 3 and 100 Hz) for inactivation of Salmonella Montevideo on the surface of black pepper. The impact of frequency, treatment time and distance from the lamp on the rate of inactivation was studied. A reduction of 4.21 1og10 CFU/g was achieved with a 35 s treatment at 16.6-cm from lamp at 1.8 Hz. Similarly, reductions of 4.72 CFU/g and 4.70 CFU/g were obtained at 14.1-cm after 35 s treatment at 3 Hz and 100 Hz, respectively. Temperature measurement of packed and unpacked black pepper indicated that packaging material absorbed a small amount of energy. Measurement of surface and internal temperature suggested that temperature below the surface increased far less than surface temperature. For instance, temperature on the surface of the black pepper can go up to 200 °C as measured by the infrared camera within 30 to 40 s treatment. However, the temperature at 1 mm below the surface was up to 100 °C depending upon the distance from the lamp. The color of the black pepper did not change after pulsed light treatment (p>0.05). These results suggest that pulsed light can potentially be used to inactivate pathogens on black pepper surface without adversely affecting its quality. M.S. in Food Safety and Technology, July 2016 Show less
