Dielectric-Based Calibration Algorithm for Rapid and Nondestructive Determination of Multiple Quality Attributes of In-Shell Nuts

Quality assessment of several agricultural commodities requires measurement of several quality attributes to determine their value, optimum processing conditions, and conditions for safe storage. A dielectric-based calibration algorithm is proposed for simultaneous and nondestructive determination of three quality attributes of in-shell nuts, namely, bulk density, moisture contents (pods, kernels, and shells), and “meat” content from the measurement of their dielectric properties at a single microwave frequency. The calibration algorithm relies on the existence of direct correlations between the quality attributes and the dielectric properties of in-shell nuts measured at a single microwave frequency. The performance of this algorithm is demonstrated through measurements on in-shell peanuts with a low-cost microwave sensor operating at 5.8 GHz. Calibration equations correlating each quality attribute with in-shell peanuts’ dielectric properties are given along with the standard error of calibration.