A pore inactivation model for describing oil uptake of French fries during pre-frying

• A pore inactivation model is proposed to describe oil uptake during frying.
• It assumed that the moisture vapour from the porous crust inhibits oil migration.
• Oil uptake is characterised as function of water evaporation and water loss.
• The model has a physical basis and provided good predictions of the oil uptake.

The reduction of oil uptake during deep-frying is a subject with societal relevance, given the trend towards lower-fat foods. Since research into oil absorption during frying is limited, we here report on developing better mechanistic understanding of this process. The oil uptake for different frying temperatures and fry dimensions was measured as a function of the water evaporation rate and water loss. A pore inactivation model was developed based on the hypothesis that the crust is a porous layer through which the exuding moisture vapour flow inhibits oil migration. Decreases in water evaporation rates will cause pores to inactivate, allowing oil to penetrate into the crust. The model provides good predictions to the experimental data. Since the model has two parameters, a purely statistical comparison with a simple linear fit having one parameter, does not show a significant benefit; however, the model better describes the overall trend of oil uptake.