ABSTRACT
The object of this research work was to develop a density-independent equation to estimate the moisture content of wheat by simultaneously measuring the relative permittivity, ε', of the product at two different frequencies using a Q-Meter. Owing to the difference observed between the measured and theoretical capacitance of the empty sample container, an analysis of errors that arise during the measurement procedure was carried out. The effect due to the presence of polystyrene beads on the dielectric properties of wheat, which were used to artificially reduce the bulk density of the seeds, was also investigated. The resulting equation was capable of estimating wheat moisture content, variety Estica, in the range from 12 to 18% w.b. with a standard deviation and a maximum error of 0.8 and 1.1 percentage points moisture, respectively. It was concluded that the proposed method does not allow the derivation of a bulk density-independent model to estimate wheat moisture content for the conditions studied.
Key words:
instrumentation; moisture content; wheat