Measurement of the Protein Composition of Single Wheat Kernels Using near Infrared Spectroscopy

Abstract

Near infrared (NIR) spectroscopy of single seeds of cereal grains would allow their quality testing to be performed at earlier stages in breeding programmes than at present and for seeds of individual lines to be sorted into fractions of contrasting quality. Previous single-kernel NIR research involving cereals has been directed at traits such as protein content and seed colour for which NIR analysis is well-established. However, the development of methods for more complex traits such as wheat protein composition, which relate directly to end product performance, would be of particular use in plant breeding applications. NIR spectra of 200 single wheat seeds representing varieties with different protein composition profiles were measured using both a dispersive and a diode array instrument together with specially-designed sample accessories. The same seeds were then subjected to biochemical analysis using HPLC methods to determine their protein compositions. Predictive models were developed which showed that NIR measurements of single seeds could be used to determine the uniformity of a wheat sample, or to sort seeds, with respect to the concentrations of protein components.