The effects of edible coatings on chicken egg quality under refrigerated storage

Abstract

Seventy-three billion chicken eggs are produced annually in the United States. However, less than 0.1% of these eggs are exported. Increasing the shelf-life of eggs may increase export sales. The goal of this research was to determine whether food-grade coatings on eggs may extend shelf-life under refrigerated storage. Four food-grade coatings were selected: paraffin wax, mineral oil, soy protein isolate, and whey protein isolate (WPI). These coatings were applied to fresh chicken eggs. The eggs were stored for 12 wk in refrigerated storage at 7 degrees C. Two replicates of the 12-wk study were conducted. Egg properties measured included Haugh units, albumen pH, yolk pH, albumen CO(2) content, vitelline membrane strength, water loss, shell strength, and shell color. Egg functionality measurements included foam volume, angel food cake volume, and emulsion stability. Statistical analysis was performed using the SAS PROC GLIMMIX method (P < 0.05). Results found that coated eggs maintained higher Haugh units beyond 6 wk compared with the uncoated eggs. Also, coated eggs maintained a higher CO(2) content and lower albumen pH than the uncoated eggs over the storage period. Vitelline membrane strength slightly decreased over time in uncoated eggs, but did not change in coated eggs. Overall, oil-, wax-, and WPI-coated eggs maintained higher vitelline membrane strength (14%) than the uncoated eggs. Coating of chicken eggs with a food-grade film (oil, wax, WPI) will extend shelf-life beyond 6 wk.

Glycerin as a factor for moderating quality changes in table eggs during storage

“…Thus, limiting carbon dioxide diffusion with substances that seal the shell can have a positive effect on the pH of the egg content and, as a result, on its technological properties. Similar observations were made by Ryu et al (2011) and Biladeau and Keener (2009), who used other coating substances. The yolk reaction also changed more slowly in the experimental group compared to the control group, which indicates that shell coating inhibits negative qualitative changes.…”

“…The shell coating affects the release of CO 2 and the alkalization of the environment and slows down negative changes in the albumen quality. Similar results were obtained for chitosan , vegetable oils (Ryu et al, 2011), and wax (Biladeau and Keener, 2009). However, among the coatings listed (for similar storage periods), the best results were found for eggs coated with glycerine solution, which may indicate the effectiveness of its use.…”

“…The yolk reaction also changed more slowly in the experimental group compared to the control group, which indicates that shell coating inhibits negative qualitative changes. However, the results obtained show lower efficacy compared to wax regarding this parameter (Biladeau and Keener, 2009). …”

“…For this reason, substances sealing eggshell pores are used to inhibit evaporation. Previous research has proven the effectiveness of using silicone oils (Edwin et al, 2013), isolated soy and whey proteins, wax (Biladeau andKeener, 2009), gelatine (Al-Hajo et al, 2012), and vegetable oils (Ryu et al, 2011). Soya oil and mineral oil emulsions with chitosan have also been assessed as coatings Wardy et al, 2011).…”

Chitosan-soybean oil emulsion coating affects physico-functional and sensory quality of eggs during storage

“…Shell coatings and refrigerated storage provide adequate means of egg preservation although coating alone has been found to be effective during short-term storage (Caner, 2005;Wardy, Torrico, Prinyawiwatkul, No, & Saalia, 2010). Various coatings from hydrocolloids, lipids, and their composites have been used to extend the shelf-life of shell eggs (Biladeau & Keener, 2009;Suppakul, Jutakorn, & Bangchokedee, 2010). Although edible films perform less efficiently than their synthetic counterparts in terms of prolonging the shelf-life of food products, they maintain an advantage of being biodegradable (Callegarin, Gallo, Debeaufort, & Voilley, 1997).…”