Purpose: This study investigated a model that was developed to predict the risk of salmonellosis from chicken parts prepared from whole chickens, sold in flow pack wrappers, and subjected to proper storage (6 h at 4°C) or improper storage (72 h at 15°C) before preparation.
Methods: The model consisted of four unit operations (pathogen events): i) preparation (contamination); ii) cooking (death); iii) serving (cross-contamination); and iv) consumption (dose-response). Data for prevalence, number, and Salmonella serotype on chicken parts were obtained by whole sample enrichment, real-time polymerase chain reaction.
Results: Improper storage increased (P<0.05) prevalence of Salmonella on raw chicken parts from 10.6% (17 of 160) to 41.2% (66 of 160) and on cooked chicken parts from 10% (4 of 40) to 52.2% (24 of 46). Mean numbers of Salmonella increased (P<0.05) from 0.003 to 3.47 log on raw chicken parts and from 0.006 to 3.15 log on cooked chicken parts after improper storage. Predominant serotypes isolated (n=111) were Typhimurium (34.2%), Typhimurium var 5- (20.7%), Kentucky (12.6%), Enteritidis (11.7%) and Heidelberg (8.1%). When chicken was properly stored before preparation, the model predicted that risk of salmonellosis was low and sporadic. However, when 0.1 to 1% of chicken was improperly stored before preparation, the model predicted that risk of a salmonellosis outbreak increased (P<0.05) linearly.
Significance: These results demonstrated that the flow pack wrapper provided a favorable environment for growth and spread of Salmonella within the package and that even when only a small percentage of packages were subjected to improper storage before preparation, risk of a salmonellosis outbreak increased significantly.