Protein composition of the grain storage proteins (evaluation using electrophoresis in polyacrylamide gel – the SDS-PAGE method) and selected parameters of bread-making quality in a set of 6 winter wheat varieties from organic and conventional growing in Central Bohemia (elevation 295 m a.s.l.) were evaluated during a two-year experiment (2004 and 2005). In comparison with the varieties from organic growing, wheat varieties from the conventional growing were characterized by twice the percentage of High Molecular Weight (HMW) glutenins, responsible for dough elasticity (conventional wheat in average 25.22%, organic wheat 12.71%). At the same time, varieties from conventional growing generally reached higher, more positive values of crude protein content and wet gluten content in grain dry matter, sedimentation index by Zeleny and yield of bread. On the other hand, wheat varieties from organic growing were mainly characterized by significantly higher percentage of nutritionally valuable albumins and globulins (organic wheat in average 17.69%, conventional wheat 7.33%). In both systems of growing the highest percentage of HMW glutenins was determined in varieties from the quality group E (elite, the most suitable for bread-making), while the varieties from the quality group C (wheat unsuitable for bread-making) reached the highest percentage of residual albumins and globulins.

Ability of wheat flour to create viscoelastic properties of dough depends on character of wheat proteins. When the flour is mixed with specific amount of water, proteins hydrate, go to interactions with specific carbohydrates and lipids and make gluten. The quality of gluten for specific final utilization depends on combination of many physical and chemical properties of the protein complex and is determined especially by optimal combination of storage proteins -gliadins and glutenins. Each of them affect rheology in a different way -viscosity is affected by gliadins (solubled in alcohol) and elasticity by glutenins (solubled in weak solutions of hydroxides and acids). Fifteen varieties of winter wheat, representing different quality classes (E, A, B, C) and different soil-climatic conditions of the Czech Republic, were used for evaluation of protein fraction composition based on discontinual sequential fractionation according to Osborne (albumins, globulins, gliadins, glutenins) and determination of parameters of technological quality of the wheat grain. Better specification of the wheat varieties for different ways of utilization will be possible based on information about relationships between protein fractions composition in the wheat grain and parameters of technological quality of wheat. It is evident from our results, that for production of quality wheat for baking, warmer conditions (such as in the sugar beet region) are better because they are better for protein synthesis in plants. Wheat varieties grown in colder conditions (cereal growing regions) typically had a higher content of starch, lower farinographic parameters and worse results of baking experiments. Wheat production from better regions should be exploitable for other ways of use (wheat for biscuits, starch, ethanol, fodder purposes). Effect of wheat grain protein fractions composition on technological quality is evident from results, too. Varieties with higher content of glutenins behaved as a technologically better varieties, suitable for baking utilization (production of the rise dough). These varieties reached for higher values of Zeleny sedimentatin index, better values of rheological parameters (farinograph, extensograph) and higher yield of bread in baking experiments.

This work is focused on the characterization and rapid analytical determination of cereal flour quality with regard to nutritional and breadmaking quality. Starch, protein and non-starch polysaccharides are the main components of cereals. The content and quality of proteins and content of damaged starch is important because of the technological quality of flours. The high content of high molecular weight proteins is substantial for bread technology especially, while soluble protein fractions and non-starch polysaccharides are important for nutrition. The set of wheat, barley and rye flours and their blends were analyzed and their properties and their qualitative parameters were determined. Principal component analysis (PCA) was used on Fourier transform-infrared (FT-IR) spectra in the 1,200-800 cm-1 wavenumber region and significant correlations of various nutritional and breadmaking parameters were observed. Results showed that the FT-IR spectroscopy and PCA can serve for rapid screening and classification of cereal flour quality.