Dielectric Properties of Fruits and Vegetables as a Function of Temperature and Moisture Content Dielectric Properties of Fruits and Vegetables as a Function of Temperature and Moisture Content

Abstract

The relative permittivity, ε’ and relative loss factor, ε” of apple, chervil, mushroom, parsley, and strawberry were measured at 2800 MHz, with a cylindrical TM₀₁₂ perturbation cavity. The measurements were made over a range of moistures and temperatures. The results show that the relative loss factor has a maximum value at an intermediate moisture content for all the fruits and vegetables investigated. The relative permittivity decreases with increasing temperature at a high moisture content, but at intermediate moisture contents ε’ increases with temperature. Equations were developed for interpolation of the relative permittivity and the loss factor.

Key Words:

• Permittivity
• loss factor
• dielectric properties
• etables
• moisture content
• predictive equations

Additional information

Notes on contributors

T. Funebo

Tomas Funebo and Thomas Ohlsson are associated with SIK, The Swedish Institute for Food and Biotechnology, 402 29 Goteborg, Sweden.

T. Ohlson

Tomas Funebo and Thomas Ohlsson are associated with SIK, The Swedish Institute for Food and Biotechnology, 402 29 Goteborg, Sweden.