Scientific journal

50 2011

Journal of Food and Nutrition Research
Summary No. 2 / 2011

The concept of single-step approximation and the non-Arrhenian kinetics in modelling the processes occurring in foods
Journal of Food and Nutrition Research, 50, 2011, No. 2, s. 133-138

Peter Šimon, Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK – 812 37 Bratislava, Slovakia. E-mail:

Summary: Modelling enables to depict physico-chemical processes taking place in foods during their production and storage. In order to describe the kinetics of processes occurring in food at non-isothermal conditions in general, the concept of single-step approximation appears to be a simple and powerful tool. In the paper, the main attributes of this concept are presented and the model-fitting and model-free (isoconversional) methods are outlined. Application of the non-Arrhenian temperature functions in the single-step approximation is suggested and justified. The following case studies are presented: (i) Kinetics of acrylamide elimination; (ii) F-, E- and C-values used for the evaluation of thermal stress in sterilised food; (iii) Induction periods and the thermooxidative stability of edible oils; (iv) Thermooxidative stability of dried milk. It is demonstrated that the non-Arrhenian temperature functions provide more trustworthy estimations of the shelf-life of food products in the extrapolation of high-temperature stability tests to ambient temperature; the Arrhenius extrapolation mostly overestimates the shelf-life predicted.

Keywords: modelling; single-step approximation; non-Arrhenian kinetics; acrylamide elimination; thermooxidative stability

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