Pulsed UV light inactivation of Escherichia coli and Salmonella in liquid egg white and its effects on quality

Conventional processing methods such as heat pasteurization are currently being used to ensure the food safety of liquid eggs. However, alternative methods are needed to improve the decontamination effect and maintain the quality of eggs. In this study, pulsed UV light treatment was evaluated for inactivation of Escherichia coli K12 NSR and Salmonella Enteritidis NSR in liquid egg white under static and flow-through processing systems with different treatment parameters. The temperature of the egg white and energy dose were measured under the two processing systems. Finally, the effects of pulsed UV light treatments on egg quality parameters including pH, color, lipid oxidation, foaming ability, and foam stability were evaluated. In the static system, the maximum log reduction obtained of E. coli K12 NSR was 1.06 log CFU/mL after 40 s pulsed UV light treatment at 5 cm in 7 mL fresh liquid egg white. The maximum log reduction of S. Enteritidis PT8 NSR was 1.76 log CFU/mL at 9cm after 40 s treatment in 5 mL fresh liquid egg white. For the flow-through processing system, the maximum log reduction obtained were 1.43 log CFU/mL for E. coli K12 NSR at 5 cm with 40 mL/min of flow rate and two passes. Overall, this study showed that pulsed UV light can inactivate E. coli K12 NSR and S. Enteritidis NSR in liquid egg white with only minor changes in egg quality.