Rapid and Nondestructive Determination of Moisture Content in Peanut Kernels from Microwave Measurement of Dielectric Properties of Pods

摘要

A method for moisture determination in peanut kernels from measurement of the dielectric properties of peanut pods at microwave frequencies is presented. The dielectric properties of peanut kernels and pods were measured in free space with a vector network analyzer and a pair of focused beam horn-lens antennas. A density-independent algorithm was used to determine moisture content in peanut kernels and pods. Moisture calibration equations with temperature correction were determined from a three-dimensional representation, and an explicit relationship between peanut pod moisture content and kernel moisture content was identified. Results presented at 6 GHz and temperatures ranging from 0.5 °C to 58 °C show that kernel moisture content can be predicted with a standard error of calibration of 0.79% and that of pods with a standard error of calibration of 0.95%.