Antimicrobial effects of soft-boiled egg pickling in soy sause against Salmonella

Abstract

The study focused on testing for Salmonella in eggs during production, transportation, and storage in Korea, intending to analyze the causes of Salmonella infections originating from eggs. It then explored the survival rate of Salmonella in eggs (initially containing about 5.3 log of Salmonella) subjected to a 4.5-minute soft-boiling process and subsequently marinated in various mixtures of soy sauce, garlic, and vinegar. These eggs were stored at temperatures of 4°C and 25°C and tested at 2 hours, 24 hours, 72 hours, and 168 hours. Additionally, the study involved extracting Salmonella from the marinated eggs and conducting SDS-PAGE analysis to observe changes in Salmonella proteins post- marination. The antioxidant capacities of different soy sauce mixtures were also measured using Total Phenolic Content (TPC) and 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assays. The results indicated that all egg samples were free of Salmonella during production, transportation, and storage, suggesting that infected eggs in Korea are primarily due to cross-contamination. The marinades demonstrated varying degrees of antibacterial activity against Salmonella, with the most significant reduction (2.85 log) observed in eggs marinated in a mixture containing 20% garlic and 20% vinegar at 4°C. All soy sauce-based marinades exhibited significant antioxidant properties. In conclusion, consuming soft-boiled eggs marinated in soy sauce contaminated with Salmonella could pose a safety risk to consumers. Therefore, it is recommended that consumers adopt proper egg-handling techniques and use pasteurized eggs to minimize the risk of contamination.