Surface decontamination of whole eggs using pulsed light technology and shelf life study of combined pulsed light and vaseline coating during room temperature storage

Abstract

It has been proved that pulsed light (PL) technology could effectively inactivate bacteria on egg surface. However, shelf life research on eggs after PL inactivation was limited. In this study, the decontamination effect of PL and interior quality of eggs during storage were investigated. In the decontamination study, shell eggs were inoculated with Escherichia coli ATCC 8879 strain and treated by PL for different intensities and pulse numbers. In the shelf life study, the non-inoculated eggs were treated by 4 procedures: untreated, PL treated, washing + vaseline coating and PL + vaseline coating. The interior qualities of the eggs were evaluated every week during storage at 25 °C for 6 weeks. The results revealed that maximum of 3.77 log CFU/egg of E. coli inactivation was achieved at PL fluence of 1.32 J/cm2 without causing significant effect (P > 0.05) on the temperature of the eggs. As storage time increased, the overall Haugh unit value and yolk index decreased, the albumen pH and weight loss increased. PL didn't affect albumen quality and there were no significant differences (P > 0.05) between washing + coating and PL + coating in the interior quality of eggs. These results demonstrate that PL has promising potential for surface decontamination of whole shell eggs as a possible industrial application.