## 3 Results
A measure of the flour's functionality is the amount of damaged starch (SD) that can be attributed to the mechanical impact acting on grain particles during grinding. Progressive milling causes an increase in the degree of starch damage, which was also confirmed by [PERSON] et al. [53] and [PERSON] et al. [11]. In the research of [PERSON] et al. [54] on the grinding of wheat endosperm (hard red winter wheat) in a ball mill, an upward trend in the content of damaged starch was shown with the progress of flour fractions extraction, but it slowed down with an increase in the grinding time. In our research, the flour streams coming from breaking and sorting passages showed a lower degree of starch damage than from the reducing passages. According to the results presented in Table 1, SD content increased with the subsequent passage of individual sections. Lower SD values were observed for the initial sorting and reducing passages with lower roller pressure, especially those for which the particle size was coarse (C1 II, C2, R1G2, R1F2). The grain is broken down by grooved break rollers which exert less pressure on the endosperm than smooth reduction rollers. In the case of reduction passes, the size of the gap decreases and the pressure of the rolls increases, increasing the starch damage [11]. Table 2 shows the selected properties of wheat flour streams as measured by Alveograph. Several properties were tested in most flour streams: baking strength (W), dough tenacity (P), extensibility (L), elasticity index (Ie), and strain hardening index (SH). High values of dough tenacity (P) (90-151 mm) were noted mainly for the flour streams from the first fractions of the sorting passages (R1-R2), the final sorting and reducing passages (R4-R5, C4-C7I) and the filtration passages from vibro-sifter (V1I-V2I, V3). The lowest \(p\) values were obtained by flours of breaking passages and passage-supporting sieving (B2-B5, DD1). These differences result from the origin of the wheat flour stream fraction from the grain zone: the amount of gluten from the middle endosperm is lower than that from the outer aleurone layers [7; 9]. The different rheological behavior of the breaking and reducing flour streams can be explained by the higher ratio of polymeric to monomeric proteins in the breaking streams than in the reducing streams [15]. Breaking passages, especially early ones, release relatively clean endosperm particles, while final passages tend to scrape residual endosperm particles from the peripheral endosperm layer, along with fine bran and germ particles [48]. In addition, the final reducing passages (C4-C6) contain more damaged starch and have higher water absorption, which improves the elasticity of the dough. When performing the alveographic test, which is carried out at constant dough moisture, flour containing a higher content of damaged starch would not be fully hydrated, resulting in higher dough tenacity [11]. Conversely, higher extensibility (L) values were obtained for the flour fraction of breaking passages (B2-B5) and intermediate flours of reducing and sorting passages (C1-C3, R3). Resistance to extension was found to be negatively correlated with damaged starch content [10]. Hence, lower L values were obtained for the flour streams from the final passages. The above characteristic determines the value of the dough configuration index P/L. High P/L indicates a resistant and inextensible dough, while low P/L indicates a weak and extensible dough [40]. The lowest were found for flour streams coming from breaking passages (B2-B5), initial reducing (C1I, C2, C3), and then sorting (DD1, R3) passages. According to the observations of [PERSON] et al. [3], streams fractions derived from dorsal and ventral endosperm were characterized by a higher baking strength (W) and elasticity index (Ie), while lower values were recorded for fractions from the sub-aleurone zone. The higher W will be, the stronger the flour will be during kneading, but the elasticity index has to be considered.