## 3 Results and Discussion
### Pasting Properties of Flour  
The observed changes in the morphology of extruded flours (see Section 3.2) may significantly affect the starch pasting process. The viscosity of starch pastes depends on several factors, among which the most important are the botanical origin of the starch, its starch concentration in the analyzed sample, the volume of solvent used, the pH level, and the presence of minerals and other biopolymers [41; 42]. For this reason, constant analysis conditions were used for all flours, and the results are presented in Table 2. The maximum viscosity increases with increasing moisture content of flours prior to extrusion (at the same temperature) and decreases significantly with the increase in temperature (at constant moisture content). Nevertheless, each extruded flour was characterized by a viscosity much lower than the flour before extrusion, which means that this process significantly affected the high degradation of starch structure. This is confirmed by studies on wheat starch, described by [PERSON] and [PERSON] [43], in which they analyzed the influence of extrusion parameters (moisture content of raw material, screw speed as well as operational \begin{table}
\begin{tabular}{c c c} \hline \hline
**Sample** & **Protein (\%)** & **Ash (\%)** \\ \hline \textless{}132 \(\mu\)m & & \\ \hline C, \textless{}132 \(\mu\)m & 9.10 \(\pm\) 0.18 \({}^{\text{A}\text{A}}\) & 0.613 \(\pm\) 0.014 \({}^{\text{A,a}}\) \\
15\%, 80 \({}^{\circ}\)C & 8.52 \(\pm\) 0.23 \({}^{\text{B,b}}\) & 0.543 \(\pm\) 0.043 \({}^{\text{B,b}}\) \\
30\%, 80 \({}^{\circ}\)C & 8.54 \(\pm\) 0.06 \({}^{\text{B,b}}\) & 0.467 \(\pm\) 0.008 \({}^{\text{C,cd}}\) \\
15\%, 120 \({}^{\circ}\)C & 8.09 \(\pm\) 0.06 \({}^{\text{C,c}}\) & 0.528 \(\pm\) 0.018 \({}^{\text{B,b}}\) \\
30\%, 120 \({}^{\circ}\)C & 8.35 \(\pm\) 0.01 \({}^{\text{BC,bc}}\) & 0.464 \(\pm\) 0.009 \({}^{\text{C,cd}}\) \\ \hline \textgreater{}132–200 \(\mu\)m & & \\ \hline C, \textless{}132 \(\mu\)m & 8.46 \(\pm\) 0.01 \({}^{\text{C}\text{b}}\) & 0.463 \(\pm\) 0.009 \({}^{\text{BC,cd}}\) \\
15\%, 80 \({}^{\circ}\)C & 9.07 \(\pm\) 0.04 \({}^{\text{A}\text{a}}\) & 0.512 \(\pm\) 0.002 \({}^{\text{A,bc}}\) \\
30\%, 80 \({}^{\circ}\)C & 8.63 \(\pm\) 0.09 \({}^{\text{B}\text{b}}\) & 0.468 \(\pm\) 0.01 \({}^{\text{BC,cd}}\) \\
15\%, 120 \({}^{\circ}\)C & 9.10 \(\pm\) 0.09 \({}^{\text{A}\text{a}}\) & 0.491 \(\pm\) 0.034 \({}^{\text{AB,bc}}\) \\
30\%, 120 \({}^{\circ}\)C & 9.16 \(\pm\) 0.03 \({}^{\text{A,a}}\) & 0.437 \(\pm\) 0.015 \({}^{\text{C,d}}\) \\ \hline \hline \end{tabular} Different superscripts (A–C) in columns indicate significant differences between particle sizes, while different lower case (a–d) indicates significant differences within the analyzed parameter (\(p<\) 0.05).  
\end{table} 
Table 1: Protein and ash content in analyzed gluten-free flours. temperature) and showed that starch gelatinization increased with increasing temperature and water content; however, as observed also in our research, when these variables act at extreme opposite values, the maximum gelatinization rate occurs. During analysis, the sample is thermostated at a high temperature (95 \({}^{\circ}\)C) and subjected to a constant mechanical shear stress, which further breaks up the starch structure. At this time, a breakdown of the viscosity of the analyzed gruel is observed. From a technological point of view, the ability of starch to withstand high-temperature heating and shear stress rates affects its suitability and is considered an important quality factor [44]. The higher the peak viscosity, the greater the breakdown, with the largest breakdown observed for flours before the extrusion process (Table 2). The higher water content in extruded flours also caused the values of the breakdown parameters, as in the case of peak viscosity. Low breakdown values occurred in flours where degradation of the starch fraction did not lead to significant viscosity peaks. Similar observations have been reported by [PERSON] et al. [45], who analyzed the cassava starch.