Modeling Internal Quality Parameters of Shell Eggs under Temperature and Relative Humidity Interaction

The study was to model and predict relationships among internal quality parameters of eggs stored under varying temperature and relative humidity combinations. A total of 192 chicken eggs was used. 48 randomly selected eggs were assigned to each of the four temperature and relative humidity combinations (ambient temperature 29oCx normal RH 60%; ambient temperature29oCxhigh RH 80%; refrigeration temperature10oCx normal RH 60%; refrigeration temperature10oCx high RH) stored for 8 weeks. 6 eggs were randomly selected weekly from each group and thereafter their albumen pH, haugh unit, albumen index and yolk index were determined. Linear and quadratic functions of simple regression were fitted to ascertain how the Albumen pH could predict other internal quality parameters of Haugh unit, Albumen index and Yolk index. Results showed that Haugh unit and Albumen index were best predicted by eggs’ Albumen pH at refrigeration and normal RH (p <0.01) storage. The corresponding R 2 of 0.90 and 0.86 from quadratic and linear functions from albumen index showed that the total variation in this internal quality parameter is explained by the albumen pH. Yolk index was not predicted from albumen pH at ambient temperature by 60% or 80% RH storage. The study also revealed that relation of either haugh unit or albumen index with albumen pH is curvilinear. The quadratic regression consistently had higher R2 across four treatment groups. Finally, haugh unit and albumen index can be predicted from albumen pH within 8 weeks of storage under refrigeration temperature at either 60% or 80% relative humidity conditions.