The impact of coatings and novel processing techniques on the functionality of table eggs during extended storage period at ambient temperature

Abstract

This study aims to evaluate the impact of various applications (Ozone, sonication, and shellac and also chitosan-lysozyme) on stored table eggs for 6-weeks at ambient temperature. In this study, the functional properties and color characteristics have been monitored. Functional characterization as assayed by foaming capacity (FC) values of eggs (albumin & whole) significantly decreased from 1,175-741 (initial) at 0 weeks to 241.6-200.3 (control), 758.3-466.2 (shellac), 560-333.3 (chitosan-lysozyme), 466.6-275 (sonication), 458.3-291.6 (ozone) at the end of storage, respectively. Eggshell surface L* values were 93.77 +/- 0.61 (control), 92.84 +/- 0.61 (shellac), 94.17 +/- 0.51 (chitosan-lysozyme), 94.62 +/- 0.52 (sonication), and 93.99 +/- 0.52 (ozone) immediately after the treatments but no major significant changes were observed during storage. The lightness (L*) of egg yolk decreased significantly (p < .05) during storage from 54.95 +/- 1.90 to 52.51 +/- 2.04 which indicates the degradation of carotenoids in the yolk and the development of brownish lipid amine-aldehydes with protein discoloration. chitosan-lysozyme, sonication, and ozone treatments significantly enhanced the surface color of the eggs. However, the shellac coating maintained the highest functionality (FC) by sealing porous among all other treatments during the storage.

Practical applications Fresh eggs are highly nutritious and susceptible to deterioration in a short period of time with the loss of carbon dioxide and moisture through pores through the eggshell surface. Therefore, using surface coating and novel treatment methods are very effective in increasing the shelf life, while maintaining the interior and functional properties. Maintaining the functionality and interior quality attributes of fresh eggs is achieved for the industry by edible coating and non-thermal emerging food processing techniques such as ultrasound and ozone. This work will be helpful for the egg industry to maintain the quality of their products in addition to prolonging the stability of the shell eggs.