abstract:     In the conducted investigations, water absorption was evaluated on the basis of the amount of water stored by gluten during its standard washing out. According to the proposed procedure, contents in freshly washed out gluten of non-absorbed water (WN), water lost under centrifugation, and absorbed water (WZ) which stays in gluten after centrifugation, were determined. Rheological properties of washed out gluten were estimated by the standard test, measuring the gluten index (IG), as well as by newly worked out tests of extrusion and creep, determining the gluten elasticity index (WEG), the total strain of gluten cylinder (εt), and the percentage in the strain of viscous flow ( UC).
    Basing on grain samples from the COBORU field experiences, the influence of wheat forms and cultivars, nitrogen fertilization levels and growing regions on the variance of studied gluten indices as well as their relationships to qualitative indices of dough and bread were evaluated. When studying the gluten changes as a result of the effect of physiological and technological processes, such as: ripening, sprouting and drying of grain, as well as flour storage, the material studied was comprised of wheat ears, taken at different grain ripeness stages, and grain and whole meal samples, treated in laboratory experiments.
    The obtained results showed that water absorption indices WN and WZ were differentiated first of all by the genotype of the wheat cultivars, only within the spring form the content of absorbed water depended decidedly stronger on the fertilization level and the growing region. As a result of grain ripening, a decrease of WN and an increase of WZ proceeded simultaneously. Opposite changes of these indices took place when the sprouting of grain intensified, and also as a result of intensive moistening and gentle drying of kernels. Higher drying temperatures as well as longer flour storage periods resulted in decreasing of the total water content (WN+WZ) in washed out gluten and increasing of its mechanical strength (IG).
    The influence of WN and WZ on the rheological properties of gluten and bread dough was different. The increase in content of non-absorbed water influenced mechanical weakness of gluten, causing IG decrease and εt increase. Additionally, it worsened the dough rheological properties, contributing to stronger softening as well as lower stability and tensile strength of the dough. Whereas higher content of absorbed water caused strengthening of gluten (IG) and an improvement in its elasticity (WEG), and also had a favourable effect on many farinograph indices of dough. Studying the character of the effect of gluten features during the baking process, it was shown that higher total water content (WN+WZ), elasticity (WEG) and extensibility of gluten (εt, UC), as well as lower IG, contributed to the forma-tion of bread loaves of larger volume and enhanced crumb.