Cereal Chem. 86(4):398-404Importance of β-glucan in human nutrition is mirrored in numerous approval applications registering β-glucan containing products as health beneficial products in accordance with forthcoming EU Health Claims Regulation. In comparison to other cereals, barley contains considerable amounts of β-glucan. Naked barley is of particular interest because it circumvents the costs and loss of beneficial substances related to dehusking. In this study, the potential of near-infrared spectroscopy as an accurate, fast and economic method of determination of β-glucan in naked barley was appraised. Four different near-infrared instruments were used to analyze 107 barley samples, in both whole grain and milled form. Importantly, both black and purple pericarp samples, which are of addi-tional nutritional interest due to high anthocyanin content, and waxy samples, which show an extraordinary high β-glucan content could be analyzed within the same calibration set as the normal samples. All tested dispersive near-infrared reflection instruments showed suitability for supervision of breeding experiments and β-glucan monitoring in food industries (R 2 > 0.78). Common, industrially used near-infrared transmission instruments also provided reasonable results, although only suitable for rough selection according to β-glucan levels. On the other hand, the Fourier transform near-infrared reflection instrument was able to perform analytical analyses (R 2 = 0.96-0.98).

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The role of bread, pasta and related products produced from milled wheat seeds is important to the human diet, so monitoring changes of starch content in developing grain is essential. Immature wheat grains are also used as a functional food, particularly as a source of water-soluble carbohydrates. The amount and variation in content of different carbohydrates changes considerably during maturation and these changes were non-destructively monitored in developing grain using near infrared (NIR) spectroscopy. Characteristic changes in three carbohydrate absorption bands [1585-1595 nm (Carbohydrate I), 2270-2280 nm (Carbohydrate II) and 2325-2335 nm (Carbohydrate III)] were identified and it was concluded that the different dynamics of carbohydrates (starch accumulation as well as synthesis/decomposition of water-soluble carbohydrates) could be followed sensitively by monitoring these three different regions of NIR spectra. Carbohydrate I represents the effect of starch accumulation during maturation based on the vibrations of intermolecular hydrogen bonded O-H groups in polysaccharides. Carbohydrate II is the manifestation of O-H stretching and C-C stretching vibrations existing unengaged in water-soluble carbohydrates whileCarbohydrate III describes the changes in C-H stretching and deformation band of poly-and mono-oligosaccharides. NIR spectroscopic techniques are shown to be effective in monitoring plant physiological processes and the spectra have hidden information for predicting the stage of growth in wheat seed.

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