X-ray fluorescence spectroscopy of eggshells as a potential raw material in the construction industry

Due to its chemical composition based on CaCO3 and low price, eggshells, as waste from one of the most widely consumed foods worldwide, are receiving increased attention in building and construction industry studies. The goal of this study was to see if the chemical composition of eggshells could be utilized to distinguish eggs from different production systems. In Serbia, eggs were taken at random from ten commercial cages and ten commercial free-range flocks. Using energy dispersive X-ray fluorescence spectroscopy (EDXRF) and a chemometrics approach, twenty eggshell samples from each flock were tested for element composition (Ca, P, Mg, Na, Al, Cu, Mn, Fe, K, S, and Zn). Analysis showed that free-range eggshells had higher levels of macrominerals (P, Mg, and Na) but lower levels of microminerals (Cu, Fe, K, S, and Mn) than caged eggshells (P<0.05). A large degree of variability within and between production systems was observed for all tested elements. The findings suggest that EDXRF and chemometric analysis of eggshell elemental profiles could provide a useful and effective tool for distinguishing between free-range and caged eggs.