Mathematical Models and Probabilistic Approaches Quantifying the Influence of Formulation, Processing, and Environmental Factors on Mould Growth: Application in Shelf Life Assessment of a Food Commodity

Mathematically, mould spoilage can be expressed as a combination of probabilities: probability to be contaminated and probability to grow (germination and mycelium proliferation) up to a visible mycelium before product consumption (Membré and Dagnas, 2016). Each probability is described by a statistical model with a response (the probability) and several factors of variation, which are linked, not only to formulation, processing, environment, but also, to shelf-life. Moreover, with cooked products, the contamination, generally, occurs after the cooking step, meaning that the contamination level is low: only one or few spores per product.

The objective of this presentation is to give the general framework built when quantifying mould spoilage, followed by an overview of the most commonly used statistical models (primary and secondary models). The differences between models built at the population or at the single spore level will be pinpointed. These framework and models will be illustrated through an example of shelf-life assessment using recent studies obtained on bakery product (Dagnas et al., 2014, 2015, and 2017).

Dagnas et al. 2017. International Journal of Food Microbiology. In press

Dagnas et al. 2015. International Journal of Food Microbioloy. 211: 86-94.

Dagnas et al. 2014. International Journal of Food Microbiology. 186: 95-104.

Membré and Dagnas. 2016. Chapter 3. In: Membré, J.-M., Valdramidis, V. (Eds.), Modeling in food microbiology. From predictive microbiology to exposure assessment. ISTE Press Ltd and Elsevier Ltd, UK, pp. 33-60.