Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/19/2012
Publication Date: 5/8/2013
Citation: Jin, Z.T., Gurtler, J., Li, S. 2013. Development of antimicrobial coatings for improving the microbiological safety and quality of shell eggs. Journal of Food Protection. 76(5)779-785.
Interpretive Summary: Eggs and egg products are the single class of foods most frequently implicated in Salmonella outbreaks and recalls. Antimicrobial coatings to decontaminate and prevent cross-contamination of shell eggs were developed in this study. Natural antimicrobials in biopolymers (polylactic acid and chitosan) coating solutions reduced Salmonella spp. on egg shells up to 99.999%, and no growth of Salmonella was observed through the end of 28 days at 4C. Coated eggs had less weight loss than non-coated eggs during 12 weeks of storage at 7C or 4C. This study demonstrates an alternative and effective intervention technology for decontaminating shell eggs.
Technical Abstract: This study was conducted to develop antimicrobial coatings to decontaminate and prevent cross- contamination of shell eggs. Egg shells were inoculated with nalidixic acid resistant Salmonella enterica Enteritidis strains OB030832, OB040159, and C405, and then treated with antimicrobial coatings. Polylactic acid (PLA) served as a non-edible polymer and chitosan served as an edible polymer to carry natural antimicrobials including nisin, allyl isothiocyanate (AIT), lauric arginate ester (LAE) and organic acids. Increase of AIT concentration or addition of nisin to AIT in PLA or chitosan coating solutions resulted in greater reduction of Salmonella. Chitosan coatings with 0.1, 0.5 and 1% of LAE reduced Salmonella by 1.7, 2.5, and 5.2 log CFU/cm2, respectively. Shell eggs treated with 1 and 0.5% LAE in chitosan coatings had non-detectable Salmonella cells (less than 0.5 log CFU/cm) after 3 and 7 days stored at 7C, respectively, and no outgrowth was observed through the end of 28 days. In addition, coating treatments significantly reduced the weight loss of shell eggs during 12 weeks of storage at 7C or 4C. This study demonstrates an alternative and effective intervention technology for decontaminating shell eggs and provides an alternative approach to reduce possible recalls and outbreaks associated with pathogen contamination on shell eggs and in egg products.