Determination of non-starch polysaccharides in cereal grains with near-infared reflectance spectroscopy

Cereal grains contain variable amounts of non-starch polysaccharides, such as arabinoxylans and (1→3),(1→4)-β-glucans (β-glucans), which are associated with their cell walls. The type and composition of these polysaccharides is of increasing interest in both human and animal nutrition. Reference analysis for these polysaccharides requires the use both enzymic and monosaccharide methods. To evaluate fully the non-starch polysaccharides present in grains, some analysts further distinguish between the soluble and insoluble fractions of these components. Near-infrared reflectance (NIR) spectroscopy provides fast, inexpensive analysis. It is, however, a comparative technique that relies on multivariate calibration of sample spectra and accurate reference analysis. It has the potential to be exploited as a rapid analytical method for nutritionally important polysaccharides. The calibration statistics for arabinoxylans and β-glucans obtained in this study suggest that NIR can be used in plant breeding, nutritional and product studies to obtain simple and rapid estimates of non-starch polysaccharides. The occurrence of wheats with high cell wall contents together with barleys with high β-glucan contents is well known. However, to date, this genetic variation has not been extensively exploited for the production of grains for use as human food ingredients.