DIFFERENT APPROACH TO QUANTIFICATION OF SELECTED GRAIN PROTEIN FRACTIONS IN WHEAT LANDRACES AND POSSIBILITY OF THEIR PREDICTION BY NIR SPECTROSCOPY

The aim of this study was to compare two different approaches to quantification of two selected protein fractions (albumins+globulins and gliadins) in grains of 24 wheat materials and to find out the possibility of their prediction by NIR spectroscopy. Results obtained by the Kjeldahl mineralization method confirmed significantly higher content compared to the HPLC/UV method. Both methods were comparable in standard error and mutual correlations are 0.53 and 0.68 for albumins+globulins and gliadins respectively. Differences in measure can be caused by the associated non-protein structures, which are measured in common with grain protein by the Kjeldahl method. The high correlations of NIR calibration equations (r = 0.88-0.99) were achieved for both methods and quantification of protein fractions. The application of the NIR system for prediction of separated protein fractions seems to be a promising method for effective screening of a great number of wheat materials.