Submitted to: National Egg Quality School Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/15/2005
Publication Date: 11/6/2005
Citation: Musgrove, M.T. 2005. Microbiology of commercial shell eggs and egg products. National Egg Quality School Proceedings. pp.1-7 Interpretive Summary:
Technical Abstract: Intact shell eggs are designed to limit bacterial contamination of egg contents, protecting a developing embryo, but also contributing to their wholesomeness as human food. In order for eggs to be involved in human enteritis, there is often temperature abuse of raw product followed by consumption of improperly cooked eggs. However, commercial washing and packaging procedures can limit the incidence of egg-borne disease. Commercial egg washing not only makes eggs more attractive to consumer, when performed according to American Marketing Service recommendations; it also results in safer eggs. Many factors contribute to the efficacy of commercial washing procedures. Eggs that are free of cracks and adhering feces, feathers, dust, or blood are easier to clean. Maintenance of cages, collection belts, and collection elevators and cleaning transport crates are important parts of delivering eggs free of cracks to the processing plant. Use of potable water, appropriate levels of detergent and sanitizer, minimizing foaming, keeping pH levels above 10 and temperatures greater than 41 C are just some of the factors that help to ensure cleanliness and safety of eggs as food. Packing eggs that are dry, into clean cartons or flats, and them refrigerating them as soon as possible are vital to limiting the growth of any microorganisms that may have remained on or in eggs after washing. Federal law dictates that eggs be stored at no more than 7 C once they have been washed and packaged. Finally, transporting properly packed eggs to retail markets or further processing vendors at 7 C under conditions that prevent damage to the shell further decreases the already low risk of egg-borne disease. Though Salmonella is most often associated with egg-borne outbreaks, psychrotrophic organisms such as Listeria and Yersinia may be involved in sporadic illnesses if eggs are consumed raw or under-cooked. However, when processed, packaged, refrigerated, handled, and cooked properly, eggs are a safe and nutritious food.