title: Microbial variability in growth and heat resistance of a pathogen and a spoiler: All variabilities are equal but some are more equal than others.
abstract: Quantitative microbiology is used in risk assessment studies, microbial shelf life studies, product development, and experimental design. Realistic prediction is, however, complicated by different sources of variability. The final concentration of microorganisms at the moment of consumption is affected by different sources of variability: variability in the storage times and temperatures, variability in product characteristics, variability in process characteristics, variability in the initial contamination of the raw materials, and last but not least, microbiological variability. This article compares different sources of microbiological variability in growth and inactivation kinetics of a pathogen and a spoiler, namely experimental variability, reproduction variability (within strain variability), strain variability (between strain variability) and variability between individual cells within a population (population heterogeneity). Comparison of the different sources of microbiological variability also allows to prioritize their importance. In addition, the microbiological variability is compared to other variability factors encountered in a model food chain to evaluate the impact of different variability factors on the variability in microbial levels encountered in the final product.
authors.affiliation: Laboratory of Food Microbiology, Wageningen University, PO Box 17, 6700 AA Wageningen, The Netherlands. Electronic address: heidy.denbesten@wur.nl.
authors.forename: Heidy M W
authors.initials: HM
authors.lastname: den Besten
authors.affiliation: Top Institute Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands; Laboratory of Food Microbiology, Wageningen University, PO Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Diah C
authors.initials: DC
authors.lastname: Aryani
authors.affiliation: Top Institute Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands; Laboratory of Food Microbiology, Wageningen University, PO Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Karin I
authors.initials: KI
authors.lastname: Metselaar
authors.affiliation: Top Institute Food and Nutrition, Nieuwe Kanaal 9A, 6709 PA Wageningen, The Netherlands; Laboratory of Food Microbiology, Wageningen University, PO Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Marcel H
authors.initials: MH
authors.lastname: Zwietering
mesh_terms: D005516:Food Microbiology; D061353:Food Storage; D006358:Hot Temperature; D007700:Kinetics; D048191:Lactiplantibacillus plantarum / Q000254:growth & development*; D008089:Listeria monocytogenes / Q000254:growth & development*; D008962:Models, Theoretical; D018570:Risk Assessment
keywords: Diversity; Heterogeneity; Prediction; Quantitative risk assessment; Sensitivity analysis