Predicting lift-off time when deep-frying potato dough snacks

TL;DR

This paper develops a mathematical model to predict the lift-off time of potato snacks during deep-frying, accounting for water evaporation, vapour dynamics, and buoyancy effects to improve cooking quality control.

Contribution

It introduces a novel multiphase model combining Stefan and thin-film equations to analyze frying dynamics and lift-off timing.

Findings

Model accurately predicts density changes over time.

Lift-off time depends on evaporation and vapour layer parameters.

Asymptotic analysis simplifies the complex model for practical use.

Abstract

When frying potato snacks, it is typically observed that the dough, which is submerged in hot oil, after some critical time increases its buoyancy and floats to the surface. The lift-off time is a useful metric in ensuring that the snacks are properly cooked. Here we propose a multiphase mathematical model for the frying of potato snacks, where water inside the dough is evaporated from both the top and bottom surfaces of the snack at two receding evaporation fronts. The vapour created at the top of the snack bubbles away to the surface, whereas the vapour released from the bottom surface forms a buoyant blanket layer. By asymptotic analysis, we show that the model simplifies to solving a one-dimensional Stefan problem in the snack coupled to a thin-film equation in the vapour blanket through a non-linear boundary condition. Using our mathematical model, we predict the change in the snack density as a function of time, and investigate how lift-off time depends on the different parameters of the problem.