Background: Slightly acidic electrolyzed water (SAEW) efficiently inactivates bacteria on the egg surface, but it may damage the eggshell’s cuticle. A protective coating applied after disinfection can prevent moisture and carbon dioxide loss.
Objectives: This study examined the efficacy of SAEW (30 mg/L chlorine), peppermint essential oil nanoemulsion (PME-NE) (25 mg/mL), and tragacanth and zedo gums (1% each) alone and in combination, in enhancing antimicrobial, sensory, and structural qualities of eggshells stored for 1, 28, and 56 days at 25 °C.
Methods: The eggs were initially subjected to treatment with SAEW and later coated using solutions of the nanoemulsion and gum. The different analyses performed included minimum inhibitory and bactericidal concentrations, agar disc diffusion assay, microbiological counts, scanning electron microscopy, and sensory evaluation.
Results: Eggs treated with SAEW, followed by coating with tragacanth and zedo gums combined with peppermint essential oil nanoemulsion, resulted in the lowest counts of total viable microorganisms (5.39 log CFU/g), Salmonella enteritidis (4.41 log CFU/g), and Staphylococcus aureus (5.03 log CFU/g) on day 56. Microbial load showed an increasing trend over time (P≤0.05). Sensory evaluation revealed the highest scores for flavor, odor, color, texture, and overall acceptability of cooked eggs and raw egg odor. Scanning electron microscopy indicated that this treatment produced the thickest and most protective coating.
Conclusion: Applying SAEW followed by coating with tragacanth and zedo gums combined with PME-NE is the most effective method to enhance antimicrobial, sensory, and structural quality of eggshells at 25 °C.