The open-ended coaxial probe technique is a popular method for measuring dielectric properties and is usually
used to measure dielectric properties of liquid or semi-solid materials over a broad frequency range due to ease of handling and high accuracy. When using the open-ended coaxial probe method to measure dielectric properties of
peanuts, the samples can not make close contact with the flat tip of the probe because of the irregular kernel shape. To solve this problem, peanut samples were ground into powder and compressed into cylindrical samples with flat surface to match the true density of peanuts. This method has been used for dielectric properties measurement of many products, such as legumes (chickpea, green pea, lentil, and soybean)