title: Dynamic predictive model for growth of Salmonella spp. in scrambled egg mix.
abstract: Liquid egg products can be contaminated with Salmonella spp. during processing. A dynamic model for the growth of Salmonella spp. in scrambled egg mix - high solids (SEM) was developed and validated. SEM was prepared and inoculated with ca. 2 log CFU/mL of a five serovar Salmonella spp. cocktail. Salmonella spp. growth data at isothermal temperatures (10, 15, 20, 25, 30, 35, 37, 39, 41, 43, 45, and 47 °C) in SEM were collected. Baranyi model was used (primary model) to fit growth data and the maximum growth rate and lag phase duration for each temperature were determined. A secondary model was developed with maximum growth rate as a function of temperature. The model performance measures, root mean squared error (RMSE, 0.09) and pseudo-R2(1.00) indicated good fit for both primary and secondary models. A dynamic model was developed by integrating the primary and secondary models and validated using two sinusoidal temperature profiles, 5-15 °C (low temperature) for 480 h and 10-40 °C (high temperature) for 48 h. The RMSE values for the sinusoidal low and high temperature profiles were 0.47 and 0.42 log CFU/mL, respectively. The model can be used to predict Salmonella spp. growth in case of temperature abuse during liquid egg processing.
authors.affiliation: Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583, USA.
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583, USA.
authors.forename: Jihan
authors.initials: J
authors.lastname: Cepeda
authors.affiliation: Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583, USA; Department of Biological Systems Engineering, University of Nebraska, Lincoln, NE 68583, USA.
authors.forename: Jeyamkondan
authors.initials: J
authors.lastname: Subbiah
authors.affiliation: Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Froning
authors.affiliation: Residue Chemistry and Predictive Microbiology Research Unit, Eastern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Wyndmoor, PA, USA.
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Juneja
authors.affiliation: Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583, USA. Electronic address: harsha.thippareddi@uga.edu.
authors.forename: Harshavardhan
authors.initials: H
authors.lastname: Thippareddi
mesh_terms: D015169:Colony Count, Microbial; D003296:Cooking; D004530:Egg Yolk / Q000382:microbiology; D004531:Eggs / Q000382:microbiology*; D005516:Food Microbiology; D006801:Humans; D008954:Models, Biological; D012044:Regression Analysis; D012475:Salmonella / Q000254:growth & development*; D013696:Temperature