Microwave moisture sensing provides a means to determine nondestructively the amount of water in materials. This is accomplished through the correlation of dielectric properties with moisture in the material. In this study, linear relationships between a density-independent function of the dielectric properties and moisture content of minced Vidalia onions, with slope dependent on moisture range, is identified. This allows prediction of moisture contents between 6% and 92%. Results showed the prediction of moisture content with a coefficient of determination of 0.976. The measurements and techniques presented in this study constitute a foundation for the development of a stand-alone sensor.