Inactivation of Escherichia coli and Salmonella in liquid egg white by pulsed UV light and its effects on quality

摘要

This study evaluated the pulsed UV light treatment for the inactivation of Escherichia coli K12 and Salmonella Enteritidis in liquid egg white. Three parameters (treatment time, volume of liquid egg white, and distance from the sample to the pulse UV strobe) have been optimized for log reductions of microorganisms using response surface methodology. The maximum log reductions obtained after 40 s of treatment time at a 5 cm of distance (the energy dose equals 45.6 J/cm(2)) were 1.28 log CFU/ml of E. coli K12 and 1.98 log CFU/ml of S. Enteritidis in 5 ml of fresh liquid egg white. A significant temperature increase of the egg white sample (from 24 to 70 degrees C) was observed at the extreme treatment condition (5 cm, 40 s). Quality evaluations indicate that pulsed UV light does not change foaming ability or foam stability of liquid egg white. However, the changes in pH, lipid oxidation, turbidity, and color of the egg white were correlated with the intensity of the treatment. Practical applications Heat pasteurization is currently being used to decontaminate liquid egg white. However, alternative methods are desired to improve decontamination as well as maintain the quality of liquid egg white. This study demonstrated the potential of pulsed UV light for the inactivation of pathogens in liquid egg white.