Functionalization of Silver/Titanium Dioxide Composites in Chitosan-based Coatings and their Egg Preservation Performances

Eggs are an excellent source of proteins, minerals, and vitamins, which have been popularly consumed in daily diet all over the world. The micro-pores and micro-cracks on the eggshells, however, lead to the loss of moisture and the escape of CO_2, resulting in the acceleration of egg deterioration and economic loss. To enhance the stability and sterilizability of the existing chitosan-based coating materials and to develop novel multifunctional nano-composites for anti-bacterial and egg preservation, silver/titanium dioxide (Ag/TiO₂) composites are synthesized and applied to modify chitosan for the extension of the egg shelf life. Electron microscope (SEM) images are used to analyze the structure and morphology of composite particles and the morphology of coated eggshells. The preservation performances of composite coatings are evaluated by various parameters: weight loss, Haugh unit, albumen pH and eggshell morphologies of the samples. Adoption of Ag/TiO₂ composites contributes to a synergistic effect to chitosan, which could prolong the preservation period further. The performances of chitosan coating, however, are presently limited by the existing particle species and concentration, which requires optimization in future studies. Methods in this study examine novel coating materials, which could be created by adding specific nanoparticles into the coating precursor, to achieve the combinative effects of the nanoparticle and the precursor, as well as to prepare novel multifunctional coatings in the field of food preservation.