Low dosages of electron beam irradiation (EBI) were applied to shell eggs to examine potential effects on physicochemical and functional properties. Prior to the assessment of physicochemical and functional properties, the antimicrobial efficacy of 2, 3 and 4 kGy dosages of EBI in shell eggs was established by the reduction of inoculated Listeria monocytogenes, Escherichia coli and Salmonella typhimurium to an undetectable level. Physicochemical changes to shell eggs receiving the same dosages of EBI were quantified by Haugh unit, free sulphhydryl groups, yolk index and lipid oxidation. Functional properties were assessed by foaming capacity, emulsifying capacity and gelling properties. A loss of thick albumen and a corresponding increase in free sulphhydryl groups in the albumen were observed after EBI, resulting in a loss of foam volume and gel hardness. Negligible changes in yolk index and lipid oxidation paralleled a retention of emulsifying capacity and gelling properties. EBI proved to be an effective method for controlling microbial growth in shell eggs without adversely affecting physicochemical and functional properties.
© 2002 Society of Chemical Industry