Density of egg interior: Looking inside an egg while keeping it intact

Density of egg interior (D_i) can be considered as universal index of the quality characteristics of the whole egg. Here, we implemented a theoretical and experimental approach to developing a method for non-invasive estimation of D_i. The derived equation showed its dependence on the egg density (D) and the content of the shell in the egg, the latter being assessed as weight and volumetric ratios. We found that, for a fairly accurate prediction of D_i, it is sufficient to include two parameters in the calculation, i.e., D and the non-destructive shell deflection. These were combined into one empirical equation that showed the calculation accuracy within this experiment at the level of R = 0.966. Determination of D_i using non-destructive methods will allow for developing a number of applications, e.g., pre-incubation egg sorting, determining the conditions and duration of egg storage, and the quality rating of table eggs by internal contents.