Carnauba wax coating preserves the internal quality of commercial eggs during storage

Abstract

The objective of this study was to evaluate the internal quality and lipid oxidation of eggs coated with a carnauba wax-based product at different concentrations and stored for up to 28 days under two temperatures. For analysis of internal quality, the eggs were assigned to a completely randomized 3 x 4 factorial design (uncoated eggs (control); eggs coated with carnauba wax at 12% concentration (Aruá®); eggs coated with carnauba wax at 15% concentration (Aruá®); four storage periods - 7, 14, 21, and 28 days). Fifteen eggs from each treatment were evaluated in each storage period, with each egg representing one replicate, i.e., 300 eggs per storage temperature (10 and 25°C). Egg weight loss, yolk percent (%), albumen percent (%), Haugh unit, yolk index, and specific gravity were calculated. Lipid oxidation of the egg yolk was measured by thiobarbituric acid reactive substances (TBARS), using 10 eggs at time 0 (fresh) and 30 eggs in each storage period (7, 14, 21, and 28 days), in triplicate, under only one storage temperature (25°C). A total of five pools, consisting of two eggs each, were used for each treatment. Each pool was considered a replicate, and each treatment consisted of five replicates. The weight loss of the eggs stored at 10°C and 25°C during the storage period was, on average, 46.1% and 37.3% lower for the eggs coated with carnauba wax than in uncoated eggs, respectively. Overall, coated eggs, regardless the concentration of the wax (12 or 15%) had higher Haugh units, specific gravity, and yolk index than uncoated eggs, in both temperatures (10 and 25°C). Uncoated and coated eggs showed similar lipid oxidation values regardless of the storage period. On the other hand, eggs coated with solutions containing 15% wax showed less oxidation than eggs coated with 12% wax. The coating of commercial eggs with carnauba wax, both at concentrations of 12 and 15%, was effective in maintaining their internal quality during storage at both storage temperatures (10 and 25°C). Eggs stored at 25°C had lower quality traits during storage compared with eggs kept under refrigeration. Coating eggs with wax did not minimize the oxidative processes in the egg yolk.