Salmonella is a bacteria that causes foodborne illness, often associated with eggs. This article clarifies the risks of Salmonella in egg whites and provides guidance for egg safety.
How Salmonella Contaminates Eggs
Salmonella can contaminate eggs through two routes. External contamination occurs when bacteria from chicken feces are present on the shell surface. While commercial eggs are typically washed, this remains a concern for unwashed eggs.
Internal contamination occurs when Salmonella transfers from an infected hen’s reproductive organs to the egg before the shell forms. This process, called transovarian transmission, means bacteria are inside the egg from its earliest stages. Though less common, internal contamination is significant because bacteria are protected inside the egg.
Egg Whites and Salmonella Risk
Salmonella can be present in egg whites. If an egg is internally contaminated, bacteria can be found in the yolk, white, or both. While egg whites possess natural protective properties, these do not always eliminate the risk.
Egg whites contain antimicrobial components like avidin, lysozyme, and a high pH level, which can inhibit bacterial growth. However, these defenses do not guarantee Salmonella’s absence, especially with a significant bacterial load. Consuming raw or undercooked egg whites, such as in protein shakes or homemade dressings, carries a risk of infection.
Safe Egg Handling and Preparation
Minimizing Salmonella risk from eggs involves careful handling and thorough cooking. Store eggs in their original carton in the refrigerator at 40°F (4°C) or colder to inhibit bacterial growth.
Avoid washing eggs, as this removes the natural protective coating, or “bloom,” and may allow bacteria to enter through pores. Wash hands, utensils, and surfaces with hot, soapy water after touching raw eggs to prevent cross-contamination. Cook eggs until the yolk and white are firm, reaching 160°F (71°C) to destroy Salmonella.
High-risk groups, including young children, older adults, pregnant individuals, and those with weakened immune systems, should avoid raw or undercooked eggs. For recipes requiring raw eggs, pasteurized eggs or egg products significantly reduce risk.
Recognizing Salmonella Illness
Salmonella infection, or salmonellosis, causes common symptoms. These include diarrhea, fever, abdominal cramps, nausea, vomiting, chills, and headache.
Symptoms usually appear 6 hours to 6 days after exposure and often last 4 to 7 days. Most healthy individuals recover without specific medical treatment. Seek medical attention if symptoms are severe, such as high fever (over 102°F), bloody stools, or signs of dehydration like decreased urination or dry mouth.