Exploring paraffin's impact on coating properties and the shelf-life of eggs coated with a cassava starch, sodium alginate, and paraffin wax mixture

Egg-coating materials were prepared by blending cassava starch and glycerol (SG), with sodium alginate (Alg) (6:2:1 w/v%, respectively) and liquid paraffin wax at various concentrations of paraffin (0–2 w/v%). The effects of the properties of this coating in maintaining egg quality when stored for 4 w at 30 ± 2 °C and 50 ± 2% relative humidity were evaluated. Tensile properties, water resistance, chemical structure, and morphology of these egg-coating films were investigated. The SG/Alg egg coatings with 0.5, 1, and 2 w/v% paraffin exhibited excellent Haugh unit values (HU) (61.4, 62.6, and 62.9, respectively) in grade A after 4 w. With increasing amounts of paraffin, the weight loss percentage, yolk, and albumen pH decreased. The egg-coating materials increased the strength of the eggshell; further, adding paraffin improved the water contact angles, water vapor transmission rate and water vapor permeability of these materials. SG/Alg/Paraffin with 0.05% paraffin exhibited increased elongation at break; however, adding paraffin at 0.1–2% deteriorated the tensile properties owing to the incompatibility of the films. HU reduction during storage related to changing of freshness, quality, and shelf life of eggs. SG/Alg/Paraffin with 2% paraffin extended the egg shelf-life when stored at 30 °C for 4 w, maintained the freshness of eggs at level A, reduced weight loss, enhanced the eggshell strength, and improved the water permeability of the eggs.