Development of an antimicrobial fungal egg tray containing orange oil and smoke for eggs preservation at room temperature

The prevention and controlled growth of pathogenic bacteria on eggs during storage and distribution at room temperature is important to ensure commercial eggs and egg products are safe for consumer. This study investigated the combined effects of orange oil (0.001%–0.004% v/w) and smoke for 10 min in paper egg tray packaging produce from the fungal pulp of Trametes versicolor. Eggs were kept in the developed paper egg tray at room temperature (30 ± 2°C). The mechanism of the combined antibacterial effects against Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus and egg quality were investigated. The combination of orange oil (0.004%) and smoke delayed all bacteria and suppressed changes in weight loss and the quality factor of eggs (Haugh unit, yolk index, albumen index) for at least 14 d. It was found that the volatile orange oil smoke in the egg tray could be passed through the structure of the cell wall and membrane of bacteria, giving rise to loss of cell viability by irreversibly damaging the cell membranes of all the bacteria in this test. Moreover, higher antioxidant activity was found on the eggs than on the eggshells, which is linked to greater shelf-life of treated eggs. The study demonstrates an improved paper egg tray packaging system and the possibility of combining released essential oils and smoke, which can be extended to egg products. Smoke can also be modified on the surface of paper egg trays easily, which shows potential in functionalizing implanted materials with antibacterial properties.