## 2 Materials and Methods  
IS Laudis wheat variety, characterized by a high content of non-starch polysaccharides, was used for the milling test. The wheat was cleaned and conditioned to 16% of moisture content and milled in an industrial scale Roller Mill (in PZZ LUBELLA GMW Sp. z o.o.o., Lublin, Poland) with a throughput of 11,800 kg/h and an extraction rate of 78%. The milling process consisted of breaking, reduction, sizing, sifting, and sorting. A schematic diagram of the industrial milling stages is shown in Figure 1.  
Indexes I and II refer to passages produced in the same grinding section that differ in granulation, wherein Index I refers to a fine flour and Index II to a coarse one. For V1-V3  
Figure 1: Schematic diagram of industrial milling station applied. streams in each vibro-sifter, two separate fractions (I and II) differing in quality, but with similar particle size, were collected in half of the sifter length. After milling, 30 different flour streams were obtained, marked as \"F--flour\" on the scheme, consisting of 4 breaking flour streams (B2, B3, B4, B5), 17 reduction and sizing mill flour streams (C1I, C1 III, C2, C3, C4, C5, C6, C7I, C7 II, R1F1, R1F2, R1G1, R1G2, R2, R3, R4, R5), 3 sitting flour streams (DD1I, DD1 III) and 6 sorting filter streams flour (V1I, V1 II, V2I, V2 II, V3I, V3 II) as shown in the Scheme (Figure 1) for individual streams. All samples were collected separately and were kept in tight plastic bags prior to further analyzes. The selected physicochemical properties of the flour mill streams were determined as follows according to ICC Standard Methods [37]: moisture content (MC) according to PN-ISO 712:2002 (ICC 110/1), ash content (A) according to PN-EN ISO 2171:2010 (ICC 104/1), falling number (FN) determined according to PN-EN ISO 3093:2010 (ICC 107/1) standard method, as well as wet gluten content (G) and gluten index (GI) according to PN-EN ISO 21415-2:2008 (ICC 155) by using a Perten Glutomatic 2200 (PerkinElmer Inc., Waltham, MA, USA). Damaged starch (SD) content of the flour mill streams samples was determined by means of an SD-Matic (Chopin Technologies, Villeneuve la Garenne, France) which provides results in AACC units [38] (PN-EN ISO 17715:2015-01). Rheological tests were performed with the following devices: Alveograph (Chopin Technologies, Villeneuve-la-Garenne, France) according to PN-EN ISO 27971:2015-07 (ICC 121), Brabender Farinograph-E apparatus (Duisburg, Germany) according to PN-EN ISO 5530-1:2015-01 (ICC 115/1), and Mixolab (Chopin Technologies, Villeneuve-la-Garenne, France) according to PN-EN ISO 17718-1:2015-01 (ICC 173) [37]. Standard Alveograph procedure was applied to evaluate the baking strength (W) as the surface area under the curve, dough strength (P) as the maximum pressure needed to blow the dough bubble expressing dough resistance, extensibility (L) as the length of the curve expressing dough extensibility, elasticity index (Ie) [39] and strain hardening index (SH) [40]. The rheological properties of the dough prepared from each mill stream were determined using Farinograph standard procedure. Water absorption (WA) (% of the water needed to obtain a dough consistency of 500 BU), dough development time (DT) (time to reach a consistency of 500 BU), DoS--degree of softening, Farinograph quality number (QN), and dough stability (S) were recorded. Rheological properties of dough prepared from each mill stream were also studied using the Chopin Mixolab based on the Chopin+ flour protocol with the following settings: mixing speed--80 rpm, total analysis time--45 min, dough weight--75 g, hydration water temperature 30 \({}^{\circ}\)C. Flour and water were added accordingly to obtain a dough with a maximum consistency of 1.10 Nm (\(\pm\)0.05) during the first test phase.