Rice Moisture Imaging Using Electromagnetic Measurement Technique

Abstract

Among many physical attributes that need to be tested on rice grain during the processing and storing process is the measurement of moisture content. Food technologists are interested in this attribute in order to determine how rice grain will be handled during processing and to get an indication of the product's quality. Because the dielectric constant of water is much greater than that of the dry material of grain, the dielectric constant of grain is correlated with its water content. Such correlation forms the basis for rapid determination of moisture content of rice grain electrically. Even though it provides relatively reliable moisture measurement it generally lacks spatial resolution. In this paper, the method based on electromagnetic imaging technique to map the two-dimensional moisture distribution in rice grain is presented. A quantitative image reconstruction algorithm employing the simultaneous iterative reconstruction technique to rapidly iterate to a final acceptance solution is described. Empirical functions of slowness value as well as dielectric constant dependence of moisture of rice grain at ambient temperature and at nominal frequency of 1 GHz are also discussed.