Kernel mass related properties of cereal grains

A system for automatic determinations of kernel-mass distributions, and for sorting of cereal grains by mass was developed. The system provides information on the obtained distributions both graphically and through conventional statistical measures. The relative variation (coefficient of variation) in kernel mass within the examined samples of wheat, rye, triticale, and six-rowed barley varieties ranged from about 20 to 30%. Distributions of mass enable close analyses to be made of the influence of conditions in the field on kernel growth. This was exemplified in a study of the effects of fungicide use on the average kernel mass, and on the internal variation in mass. Relationships between size (mass) and other kernel properties are revealed easily on the basis of mass-sorted fractions. Through analyses of kernels within a mass fraction, relationships between, eg. kernel shape and other properties can be determined. Knowledge about these internal variations is required for optimal sorting, and thereby for optimal use, of grain. The distributions of kernel properties within grain lots are suitable as a basis for studies of variations between stands. In the thesis, the potential of the ability to sort grain by mass was exemplified in five studies. 1) The relationship between the main dimensions and kernel mass of wheat grains was analyzed at two moisture levels. The dependencies on kernel mass of equivalent dimensions, bulk density and sphericity were studied. 2) The effects of kernel mass and of shape on drying rate of wheat grains were investigated by fitting thin-layer drying curves to semi-empirical and theoretical solutions to the diffusion equation and comparing the derived coefficients. 3) The variations in kernel properties of protein were analyzed in eight wheat varieties. SDS volumes, wet gluten content, and gluten index were used to estimate the value for bread-making of the protein components in the kernels. 4) The relationships between concentration of ergosterol, commonly used as a marker for fungal growth, and kernel mass were analyzed in five winter grain varieties. 5) Extract yields and beta-glucan concentrations were determined for different size barley kernels