Modeling the effect of immersion fluids on the radiofrequency heating performance of cornflour

Abstract

Non-uniform heating is a significant challenge in radiofrequency (RF) heating of low moisture foods. Previous experiments showed that the immersion of fluids (air, deionized water, and soybean oil) changed the RF heating uniformity and rate of cornflour. However, the behind mechanism is not well understood. This study developed a finite-element-based model that incorporated quasi-static electromagnetics and Fourier’s heat transfer to understand the effect of the three immersion fluids on the RF heating performance of cornflour. The model was validated and showed good agreement with experimental thermal images. The simulation results showed that the immersion of soybean oil increased the average heating rate and improved the heating uniformity compared to immersions of air and deionized water. Less distortion of electric potential reduced the fringe effect of edge heating and thus improved the heating uniformity. The higher heating rate was attributed to more dissipated power within the cornflour sample and less surface heat loss from cornflour to the surrounding fluid than the immersion of air or water. The use of soybean oil as immersion fluid could be a promising strategy to be implemented with RF technology to improve heating performance of low moisture food products.

Keywords:

• Low moisture foods
• radiofrequency heating
• uniformity
• heating rate
• immersion fluid
• modeling

Conflicts of interest

The authors declare no conflicts of interest.

Additional information

Funding

This project is based on research that was supported by the Tennessee Agricultural Experiment Station with funding from the Hatch Multistate Research capacity funding program (Accession Number 1023982) from the USDA National Institute of Food and Agriculture.

Notes on contributors

Qianyi Chen

Qianyi Chen Methodology, Data curation, Investigation, Software, Visualization, Writing – original draft.

Damla Dag

Damla Dag Methodology, Investigation, Writing – review & editing.

Fanbin Kong

Fanbin Kong Conceptualization, Investigation, Writing – review & editing.

Ran Yang

Ran Yang Data curation.

Jiajia Chen

Jiajia Chen Conceptualization, Investigation, Supervision, Project administration, Funding acquisition, Writing – review & editing.