Development of a coating material for shell eggs is important because
of economic loss from shell damage and decline in interior egg quality
. Studies were done to evaluate the interior quality (moisture loss, H
augh unit, and pH) and shell properties (strength, thickness, morpholo
gy, and color) of uncoated eggs and eggs coated with mineral oil or wi
th solutions of egg albumen, soy protein isolate, wheat gluten, or cor
n zein. Coated shell eggs were evaluated during 1, 3, 5, 7, 10, 14, 21
, and 28 d of storage at room temperature. Eggshells coated with corn
zein solution exhibited the least moisture loss and the strongest shel
l strength. Light microscopy depicted a more compact structure of eggs
hells coated with corn zein solution. Shell eggs coated with corn zein
exhibited the lowest moisture loss and maintained a higher Haugh unit
than eggs coated with other treatments. Results also indicated that t
he protein-based coatings, corn zein and wheat gluten, added strength
to the shell, which, in turn, served as a protective barrier.