###### Abstract
Arabinoxylans are non-starch polysaccharides that are present in the endosperm (3-5% of the total endosperm), aleuarone, and bran cell walls (about 60-70% of the total cell wall). Arabinoxylans are built of a single main chain consisting of xylose residues linked by a \(\beta\)-1,4 chain, to which single arabin residues are attached in positions C-3 and simultaneously C-2 and C-3 [23]. In the case of wheat bran, AX constitutes 10.9 to 26% of all bran fractions [24]. As with protein and ash, arabinoxylans are not evenly distributed in the wheat grain. The concentration of AX in the middle endosperm is much lower compared to the outer layers of the wheat grains [6]. Despite the low content of AX in flour, they have an important impact on the quality of gluten and dough, affecting especially bread quality [25; 26]. A special feature of AX is the binding of very large amounts of water. Hence, it plays an important role in water management during bread production [27]. The interactions of proteins and AX affect the properties of gluten and dough [28]. WEAX have unique physical properties such as the ability to bind 10 times their own weight of water [29; 30], forming highly viscous solutions and gels due to their covalent cross-linking [31; 32]. All these properties have a direct functional impact on the formation of gluten and the properties of the dough. In general, it is believed that WEAX have a positive effect on bread quality [33] and WUAX have a negative effect [34; 35]. The total arabinxylan (TAX) content can be empirically divided into water extractable arabinoxylans (WEAX) or water non-water extractable arabinoxylans (WUAX) fractions. WUAX and WEAX have different physicochemical properties [6]. WUAX impinges upon the molecular mobility of water [23] and negatively influences the quality of bread by binding large amounts of water, which prevents proper hydration of starch and gluten. WUEX also affects the proper formation of air bubbles during fermentation in bread dough [18]. In the WEAX fraction, ferulic acid residues are available for oxidative crosslinking induced by free radicals and are partly responsible for changes in dough viscosity [6]. It is therefore of interest to determine the distribution of arabinoxylans in the flour streams in order to compose proper flour stream blends to obtain a functional flour with specific properties without the use of additives or further treatments. Earlier studies on the distribution of arabinoxylans in mill streams characterized the relationship between the content of AX in individual flour fractions and the technological suitability of specific flour passages to a limited extent [4; 11; 16; 17; 21; 36]. These studies have often been more focused on the structural characterization of AX from various mill streams and less on their comparison with the most commonly used methods of quality and technological suitability assessment. Understanding the differences between the functional characteristics of different mill streams would improve the efficiency of their composition and the quality of the final blend for various applications [6]. The aim of the study was to evaluate several physiochemical and rheological properties of wheat flour mill streams, including arabinoxylans content and fractions structure, to analyze its distribution so as to optimize flour passage composition.