Kinetics of growth and inactivation of Salmonella enterica serotype Typhimurium DT104 in pasteurised liquid egg products.
The potential impact of post-pasteurisation contamination of liquid egg products with the multi-antibiotic resistant pathogen Salmonella enterica serotype Typhimurium definitive type 104 (DT104) was assessed by determining the viability of this bacterium in whole egg, albumen and 10% w/w sugared and salted yolk incubated at 4-42 degrees C. Results indicated that populations of S. Typhimurium DT104 were slowly inactivated in all four products when stored at 4 degrees C. However, based on the typical shelf-lives of cold-stored liquid egg, less than 0.6 log-kill would be achieved in those products prior to their use. Incubation at temperatures pertaining to abuse situations (10, 15, 20 and 25 degrees C) revealed an increasing potential for growth of S. Typhimurium DT104 in whole egg, albumen and sugared yolk, as indicated by trends in growth rate, lag duration and maximum population density. At even higher temperatures (30, 37 and 42 degrees C), growth rates of S. Typhimurium DT104 in whole egg and sugared yolk continued to increase. The same was true for S. Typhimurium DT104 in albumen except that growth was not observed at 42 degrees C and instead populations were inactivated within 30 h. At no temperature tested was S. Typhimurium DT104 able to grow in salted yolk. The influence of these growth and inactivation patterns on the risk of salmonellosis in relation to product type and storage temperature is discussed.
Tasmanian Institute of Agricultural Research, School of Agricultural Science, University of Tasmania, Hobart, Tasmania 7001, Australia. Olivia.McQuestin@utas.edu.au
Olivia J
OJ
McQuestin
Michael T
MT
Musgrove
Mark L
ML
Tamplin
D000418:Albumins / Q000378:metabolism; D019540:Area Under Curve; D050260:Carbohydrate Metabolism; D015169:Colony Count, Microbial; D004529:Egg White / Q000382:microbiology; D004531:Eggs / Q000382:microbiology*; D005506:Food Contamination / Q000032:analysis* / Q000517:prevention & control; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D006358:Hot Temperature; D006801:Humans; D007700:Kinetics; D011157:Population Dynamics; D011158:Population Growth; D012478:Salmonella Food Poisoning / Q000517:prevention & control; D012486:Salmonella typhimurium / Q000254:growth & development*; D012492:Salts / Q000378:metabolism; D013696:Temperature
D000418:Albumins; D012492:Salts