Impact of whey protein isolate/sodium montmorillonite/sodium metabisulfite coating on the shelf life of fresh eggs during storage

The effect of protein-based coating made with whey protein isolate (WPI), sodium montmorillonite nanoparticles (MMT-Na), and sodium metabisulfite (SMB) on the internal quality (weight loss, Haugh unit, yolk index, albumen pH, yolk pH, foam stability, and overrun) of eggs was evaluated for 8 weeks of storage at 25 +/- 3 degrees C and 70 +/- 5% RH. The coating was applied by immersion of eggs, followed by drying at room temperature. Uncoated eggs were used as a control. The coated eggs maintained grade A for up to 5 weeks, while the grade of the control eggs lasted about a week. Significant lower weight loss was observed for the coated eggs after 8 weeks of storage when compared to the control, with values of 11.65% and 14.50%, respectively. The protein-based coating improved foam stability (>75%) when compared to the control (43.45%) due to the small changes in pH of the albumen, after 5 weeks of storage. The control eggs lasted only 5 weeks under the storage conditions of this study, thus the internal quality was not determined after this period, while the coated eggs maintained integrity for up to 8 weeks.

Automated summary

The protein-based coating made with whey protein isolate, sodium montmorillonite nanoparticles, and sodium metabisulfite can prolong the storage life of eggs and maintain internal quality, such as reducing weight loss and improving foam stability.