MAP storage of shell hen eggs, Part 1: Effect on physico-chemical characteristics of the fresh product

The aim of this study was to compare some physico-chemical properties (O2 and CO2 in the package headspace, weight loss, pH, albumen and yolk water content and colour, Haugh unit) of non packed eggs and eggs packed in high barrier plastic pouches with three atmospheres (air, 100% N2, 100% CO2) during 28 days of storage at 25 °C. Modified atmosphere packaging (MAP) permitted a strong reduction of the weight loss from the product. While the greatest quality decline was observed for the control eggs (not packed), eggs packed in CO2 maintained the initial values of Haugh unit during storage and the albumen pH was about 2 units lower than in the control group. Nevertheless, the light yellow colour of CO2 sample albumen deepened and the shell gradually developed a powdery surface. MAP with 100% N2 did not promote any additional benefits to the eggs in comparison with the product packed in air.