# The Influence of Arabinoxylan on the Properties of Sourdough Wheat Bread
## 3 Results and Discussion  
The composition and properties of the flour were typical of wheat flour type 750 (Table 1). The content of ash, starch, protein and fat (Table 1) determined in the tested flour was typical for this type of flour [40; 41; 42; 43; 44]. The content of total dietary fiber in the wheat flour was also similar to other studies, as this component constitutes 3.0-3.6% for flours with a similar ash content [45; 46; 42]. The content of soluble fiber (SDF) in the tested flour was slightly higher, while insoluble fiber (IDF) was lower compared to the other studies regarding flour type 650, in which these values were 1.2% and 1.8%, respectively [46]. The content of AXs and the ratio of arabinose to xylose (Table 1) in the wheat flour studied corresponded to data presented in the literature [47; 48; 49]. Table 2 presents the content and molecular properties of the AXs in the AX preparations isolated from rye grain. The AX preparations were determined as follows: unmodified (AX_NM), partially hydrolyzed (AX_HYD) and cross-linked (AX_CR). The AX content in the preparations at the level of approximately 78% indicated the high purity of the preparations and was typical compared to the content reported in other studies for rye AX preparations, ranging from 68 to 93% [50; 51; 52]. \begin{table}
\begin{tabular}{c c} \hline
**Component** & **Wheat flour Type 750** \\ \hline Starch [\%] & 75.3 \(\pm\) 0.9 \\ Protein [\%] & 12.2 \(\pm\) 0.6 \\ Fat [\%] & 1.7 \(\pm\) 0.1 \\ TDF [\%] & 3.2 \(\pm\) 0.1 \\ SDF [\%] & 1.5 \(\pm\) 0.0 \\ IDF [\%] & 1.7 \(\pm\) 0.0 \\ AX [\%] ** & 2.2 \(\pm\) 0.2 \\ A/X ** & 0.56 \(\pm\) 0.04 \\ Ash [\%] & 0.72 \(\pm\) 0.01 \\ \hline \end{tabular} \({}^{\star}\)IDE—total dietary fiber, SDF—soluble dietary fiber, IDF—soluble dietary fiber. \({}^{\star}\) AX—the sum of the content of arabinose and xylose after acid hydrolysis and multiplying the result by a factor of 0.88. A/X—the ratio of arabinose to xylose.  
\end{table} 
Table 1: Chemical composition of flour. \begin{table}
\begin{tabular}{c c c c} \hline
**Component** & **AX_NM** & **AX_HYD** & **AX_CR** \\ \hline AX [\%] & 78.2 \(\pm\) 1.3 \({}^{\text{a}}\) & 77.7 \(\pm\) 1.0 \({}^{\text{a}}\) & 77.6 \(\pm\) 1.5 \({}^{\text{a}}\) \\ Molecular parameters of AX & & & \\ M\({}_{\text{w}}\) [g/mol] & 446,330 \({}^{\text{b}}\) & 190,440 \({}^{\text{a}}\) & 574,710 \({}^{\text{c}}\) \\ M\({}_{\text{n}}\) [g/mol] & 12,600 \({}^{\text{b}}\) & 6290 \({}^{\text{a}}\) & 13,400 \({}^{\text{c}}\) \\ D & 35.4 \({}^{\text{b}}\) & 30.3 \({}^{\text{a}}\) & 42.9 \({}^{\text{c}}\) \\ \hline \end{tabular} \({}^{\star}\)X\_NM—non-modified AX preparation; AX_HYD—hydrolyzed AX preparation; AX_CR—cross-linked AX preparation. Mean values in rows marked with the same letters are not statistically significantly different at \(p<0.05\).  
\end{table} 
Table 2: Arabinoxylan content and molecular parameters of water-soluble arabinoylan (AX) obtained from rye wholomeal. The molar mass of unmodified arabinoxylans (AX_NM) was typical of water-soluble rye AXs, which, according to data from other studies, have a molar mass in the range of 200,000-500,000 g/mol [27, 52]. The AXs in the AX_HYD preparation modified using partial enzymatic hydrolysis were characterized by a low molar mass, which was similar to that determined as 219,000 g/mol in a study by [PERSON] [52], where the same method of AX modification was used. The AXs in the preparation of cross-linked arabinoxylans (AX_CR) had the highest molar mass, and this value was higher than the molar mass of 505,000 g/mol determined for AX obtained using the same method [52]. The determined molar masses of the AXs indicate that the process of isolation and modification (cross-linking and partial hydrolysis) of the AXs was carried out correctly. Table 3 shows the water binding capacity (WBC) of wheat flour, and the dough yield (DY) and baking losses (BL, TBL) of the sourdough wheat bread without and with the AX preparations.