Dielectric properties-based method for rapid and nondestructive moisture sensing in almonds

Abstract

ABSTRACTA dielectric properties-based method is presented for rapid and nondestructive determination of moisture content in almonds independent of bulk density. The method relies on measurements of the dielectric properties at microwave frequencies. The dielectric properties of almonds were measured between 5 and 15 GHz, at 1-GHz increments, for samples with moisture contents from 4.8% to 16.5%, wet basis, bulk densities from 0.565 to 0.7 g/cm3 and temperatures ranging from 5.2 to 45 °C. Moisture calibration equations are given for several frequencies, at room temperature (25 °C) and with temperature compensation for temperatures between 5.2 and 45 °C, along with their respective standard errors of performance, which ranged from 0.44% to 1.06% depending on frequency.