Geometric Parameters of Wheat Grain Determined by Image Analysis and FEM Approach

Digital image analysis was used to test the quality parameters of six varieties of Triticum aestivum L. and one variety of Triticum duro-compactum L. - projected area, equivalent diameter, MaxFeret and MinFeret (minimum or maximum perpendicular distance between parallel tangents touching opposite sides of the profile of the chosen object), perimeter, thickness and crease depth (both measured using a digital calliper) of a kernel ranging from 16.52-20.22 mm(2), 4.58-5.07 mm, 16.70-20.82 mm, 6.21-7.29 mm, 3.32-3.78 mm, 2.69-3.12 mm, 0.23-0.42 mm. The size data were used for calculation of volumes and surface areas of wheat kernels modelled as a general ellipsoid. The calculation of surface area using finite element method (FEM) was based on computer software MAPLE 9.0 and the results were compared with a simplified method. The volumes of kernels from the ellipsoid model were corrected with consideration of measured average crease depth; the difference was then max. 3.6%. We tested the correlation of volume and surface areas obtained from the ellipsoidal model with the measured projected areas; the resulting high correlation coefficient for the varieties of Triticum aestivum enables the use of only 2D image analysis measurement, for quick estimation of surface and volume parameters, without time consuming thickness measuring. However, the shape of Triticum duro-compactum kernels was a little different and the designed geometrical model was thus not suitable. We recommend image analysis as a simple and rapid method for obtaining the parameters of wheat grain for engineering purposes.