Effects of Whey Protein, Aloe Vera, or Carnauba Wax Biofilms on the Internal Quality of Eggs from 86-Week-Old Hens

Egg quality loss during storage is a major concern in the poultry industry, particularly for eggs from older hens, which are more susceptible to shell thinning, albumen liquefaction, and yolk weakening. This study evaluated the effect of whey protein, Aloe vera, and carnauba-wax coatings on the internal quality of eggs from 86-week-old laying hens stored at room temperature for 21 days. The experimental design consisted of four treatments (uncoated control and three coatings) and four storage times (0, 7, 14, and 21 days). Internal quality was assessed by Haugh unit (HU), yolk index (YI), albumen pH, and yolk color parameters (L*, a*, b*). The results showed that storage time significantly affected all internal quality traits (p < 0.05). Whey protein coating consistently maintained higher HU and YI values and lower albumen pH compared with the control, indicating better preservation of albumen viscosity and CO2 retention. Aloe vera and carnauba-wax coatings had only transient effects, with values similar to the control after 14 days. Yolk color stability also declined over time, with minor protection observed only for the whey protein treatment. In conclusion, whey protein coating provided the best overall preservation of egg internal quality during storage, demonstrating superior gas barrier properties and structural stability. These findings suggest that protein-based coatings may be an effective strategy to extend the shelf life of eggs from aged laying hens.