Surface decontamination of whole-shell eggs using far-infrared radiation

• Infrared processing for surface pasteurization of whole shell eggs were investigated.
• Surface temperature changes were related with the microbial reduction data.
• Changes in the physical properties of the eggs after infrared processing were investigated.
• Applicability of infrared processing for surface pasteurization was demonstrated.

Shell eggs from healthy chickens are assumed sterile inside, but numerous microorganisms might be present on the shell. While warm water and controlled microwave applications are some common whole egg pasteurization processes, surface decontamination might be a feasible process since majority of microorganisms are located over the shell. With infrared application's direct influence on the surface, similar to the case of pulsed light and ultra-violet applications, the objective of this study was to determine its potential for surface decontamination of whole-shell eggs. For this purpose, shell eggs were inoculated with E. coli ATCC 25922 strain, considering its similar resistance compared to Salmonella Enteritidis to heat, and processed under infrared conditions from 180 to 350 °C. Processing at 250 °C for 110 s resulted in 3.37 log cycle reduction without causing any denaturation in albumen and adverse effects in yolk index, Haugh unit, albumen pH and foaming capacity. These results demonstrated the potential of infrared heating for surface decontamination of whole shell eggs as a possible industrial application.