Comparative Evaluation of Different Methods to Determine the Crude Gluten Content in Wheat Grain

A multiple nonlinear regression equation reflecting dependence of the crude gluten content in wheat grain (Y, %) on the protein content (X1 = Ntotal × 5.7, %) and thousand kernel weight (X2, g) : Y(1) = –41.928 + 0.081 $$X_{1}^{2}$$ + 2.548X2 – 0.028 $$X_{2}^{2}$$ has been developed using regression analysis. For this equation, all grain quality indices correspond to the 12% moisture level. In the case when the protein content is determined for absolutely dry matter, the dependence is described by the following equation: Y(2) = –41.928 + 0.063 $$X_{1}^{2}$$ + 2.548X – 0.028 $$X_{2}^{2}$$ . The developed equations can be used to forecast the crude gluten content in both winter and spring grain as well as soft and hard wheat varieties in all cases when the indices of its technological quality are determined by traditional analytical methods. The equations are also suitable for indirect verification of the accuracy of the crude gluten content determination if the content of protein and/or crude gluten is measured by different devices, such as InfraLUM FT-10 or FT-12, Spektra Star 2400, Infraneo, DA 7200 NIR analyzer, Inframatic 9200, and Infratec 1241.