In this study, UV-C and mild heat treatments were used alone or in combination for the inactivation of Salmonella Typhimurium and Escherichia coli O157:H7 on the black pepper powder. The treated pepper powder was analyzed microbiologically, and the physicochemical properties of the pepper powder were examined. UV-C combined with heat treatment at 60 °C most effectively inactivated the pathogens. However, heat treatment at 60 °C produced many injured cells and greatly reduced moisture content of the pepper powder. UV-C combined with heat treatment at 45 °C showed significantly (p < 0.05) similar inactivation results as that with heat treatment at 60 °C after 18 min. In addition, the combined treatment minimized the moisture loss and color change of the pepper powder compared to heat treatment at 60 °C. Thus, UV-C and heat treatment at 45 °C can effectively inactivate pathogens while maintaining the quality of black pepper powder.
Keywords: Black pepper powder; Escherichia coli O157:H7; Mild heat; Salmonella Typhimurium; UV-C.