Chitosan coatings and chitosan nanocomposite to enhance the storage stability of fresh eggs during storage

Bio-based coatings contribute to enhance the shell quality and maintain fresh eggs' quality consequently contributing to the reduction of food losses. Biopolymer chitosan with three different (1%, 4%, and 8%-w/w) concentrations and also chitosan-montmorillonite (MMT-1%) nanocomposites were used in the production of coatings to maintain the storability of fresh eggs (pH, Haugh Unit, Yolk Index, foaming power-RWC, shell breakage, and rheology) for 4 weeks storage (24 degrees C). The coatings sealed the pores of the eggshell, so it reduced breakage, and the mass transfer and increases the storability of the eggshell. Haugh unit (HU) differences in significance were observed between uncoated and coated fresh eggs after 2 weeks. The HU of eggs with chitosan-MMT (58.2) and chitosan 8% (58.1) had a significantly higher HU than control (37.3) and chitosan-1% (54.5) after 4 weeks of storage. This study showed that chitosan coatings acted as a protective barrier for maintaining the interior quality of the fresh eggs. The RWC for the chitosan-coated eggs was higher than the uncoated ones at all storage periods. Eggs coated with chitosan-4, chitosan-8%, and MMT had lower yolk pH values significantly than those control after 2 weeks and chitosan 1% after 2 weeks. A significant difference, among all chitosan-coated ones after 4 weeks of storage, was not found. The results underline that the chitosan coatings preserved the RWC of eggs and it is due to an efficient barrier property against the loss of CO2, avoiding changes in the pH of the egg albumen during storage. Novelty impact statement Coatings using chitosan-montmorillonite may help retail sectors in minimizing the economic losses due to breakage or cracks. Chitosan-montmorillonite coatings were efficient in minimizing the permeability of the shell by sealing eggshell pores. The storage stability of eggs was enhanced by bio-based coatings.