title: Survival and growth of Salmonella Enteritidis in liquid egg products varying by temperature, product composition, and carbon dioxide concentration.
abstract: Cryogenic cooling of shell eggs with carbon dioxide (CO(2)) is known to improve egg content quality through rapid cooling as well as by increasing internal CO(2) levels. A study was undertaken to determine the effects of variations in atmospheric CO(2) concentrations (aerobically stored, flushed with CO(2) and sealed, or bubbled with CO(2)) on the survival and growth of Salmonella Enteritidis in liquid egg products including whole egg, albumen, yolk, and albumen + 1% yolk. Egg products were inoculated with a three-strain composite of Salmonella Enteritidis at ca. 4 log colony-forming units (CFU)/mL and stored at 7 degrees C or 10 degrees C for 8 or 4 days, respectively, or at ca. 2 log CFU/mL and stored at 23 degrees C and 37 degrees C for 48 or 24 hours, respectively. Salmonella populations differed based on variations in liquid egg composition (p < 0.05). Manipulating the atmospheric concentrations of CO(2) in which liquid egg products were stored did not significantly inhibit the growth of Salmonella Enteritidis (p > 0.05) in yolk-containing egg products or affect the inhibitory activity of albumen-containing products. Populations of Salmonella were static at 7 degrees C over the entire storage period and significant growth occurred in whole egg and yolk stored at 10 degrees C. Populations in egg stored at 23 degrees C and 37 degrees C were greater in yolk than in whole egg, although whole egg had populations greater than in albumen or albumen +1% yolk (p < 0.05). Results of this investigation suggest that increasing atmospheric CO(2) to enhance egg quality should not promote the growth of Salmonella Enteritidis in eggs.
authors.affiliation: Food Safety Intervention Technologies Research Unit, North Atlantic Area, Eastern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, Pennsylvania 19038-8505, USA. joshua.gurtler@ars.usda.gov
authors.forename: Joshua B
authors.initials: JB
authors.lastname: Gurtler
authors.forename: Donald E
authors.initials: DE
authors.lastname: Conner
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000008:administration & dosage*; D002645:Chickens; D003080:Cold Temperature; D004530:Egg Yolk / Q000382:microbiology; D004531:Eggs / Q000032:analysis / Q000382:microbiology*; D005260:Female; D005519:Food Preservation / Q000379:methods*; D050296:Microbial Viability; D010047:Ovalbumin / Q000032:analysis; D012477:Salmonella enteritidis / Q000254:growth & development* / Q000502:physiology; D013696:Temperature
chemical_list: D002245:Carbon Dioxide; D010047:Ovalbumin