Modeling the Physical Properties of Popcorn Varieties as a Function of Kernel Moisture Content

The physical properties such as the axial dimensions (length, width, thickness), geometric mean diameter, thousand kernel weight, shape characteristics (sphericity, kernel volume, kernel surface area), bulk density, particle or kernel density, as well as porosity have been evaluated as a function of kernel moisture content for pin and deep yellow varieties of Nigerian popcorn kernels. It has been observed that the length, width, thickness as well as the thousand kernel weight increase with increasing moisture content for both varieties under investigation in the moisture range 11-17% (wet basis.), while the bulk and particle densities together with the kernel porosity have been found to decrease with increasing moisture content. These physical properties vs moisture content dependencies have been fitted to linear, polynomial and other non-linear equations and the empirical constants determined for each case. Regression analyses have revealed that the third-order polynomial and quadratic functions more adequately describe the observed dependencies than the linear equation in most cases, based on the resulting correlation coefficients and standard errors.