Modeling and simulation of Talaromyces flavus growth in pineapple: an integration between kinetic and transport phenomena models

Abstract

The study of the dynamic behavior of microbial growth in foods is extremely important to extend the shelf life of foodstuff. In this work, a kinetic model describing the growth of Talaromyces flavus in pineapple was integrated with a thermal model. The integrated model was used in order to simulate the product’s shelf life in heating scenarios. Kinetic experiments were performed in 4 distinct temperatures (from 20 °C to 35 °C), and statistical indices were used to select the best primary and secondary models. The thermal model was developed based on the analytical solution of the heat diffusion equation for flat plates and infinite cylinders. It was shown that the modified Gompertz model (BF=1.003, AF=1.049, RSS=3.687 and RMSE=1.286), along with the extended square root model (BF=0.999, AF=1.012 and RSS=0.2684) and the second order polynomial model (BF=0.991, AF=1.011, RSS=0.006 and RMSE=0.078) were the most satisfactory models. The kinetic model was validated in both static and dynamic temperature conditions (in two distinct scenarios) to assure that it could be integrated with the heat transfer equations. Simulations had shown a 23.3% increase in shelf life increasing the product’s length (from 2 to 30 cm) and an 88.2% increase with the diminution of the ambient air temperature (from 34 °C to 22 °C). Less pronounced effects were obtained varying the product’s diameter and the velocity of the ambient air.

Keywords:
Predictive mycology; Primary models; Secondary models; Heat transfer; Fruit; Fungus