Theoretical reasons for rapid heating of vegetable oils by microwaves.

Water and high-moisture foods are readily heated in microwaves due to their relatively high dielectric loss factors. Vegetable oil, on the other hand, has a much smaller loss factor (about 1/100 that of water), and is generally believed to be unsuitable for microwave heating. In this study, we conducted experiments to compare heating rates between vegetable oil and pure water in a 2450 MHz microwave oven.

Effect of changes in salt content and food thickness on electromagnetic heating of rice, mashed potatoes and peas in 915 MHz single mode microwave cavity.

A mathematical model for predicting electromagnetic power dissipation within a rectangular dielectric slab heated by equal intensity 915 MHz plane waves from top and bottom was developed. A dimensionless parameter (J-T number) which is a combination of the loss factor (ε), dielectric constant (ε) and food thickness (L) was proposed. This unique number provided direct insight into the relationship between food dielectric properties, thickness, product temperature, and thermal lethality.