# Sorghum Flour: A Valuable Ingredient for Bakery Industry?
## 3 Results and Discussion
### Rheological Properties of Flour Mixtures  
Table 6 presents the rheological properties of wheat and sorghum flour mixtures, versus the trial simple wheat flour.  
Mixolab C1-C5 values of wheat dough were 1.098 N\(\cdot\)m, 0.462 N\(\cdot\)m, 1.924 N\(\cdot\)m, 1.809 N\(\cdot\)m and 3.049 N\(\cdot\)m, respectively (Table 6). Similar Mixolab behavior was mentioned in other studies [27] for three wheat varieties with small differences.  
From our results, it can be seen that as the amount of added sorghum seed flour increases, the water absorption capacity decreases from 58.2% (wheat) to 54.7% (30% sorghum), 53.4% (35% sorghum), and 52.7% (40% sorghum), respectively. For wheat flour for baking, normal CH values are between 55-62% [37].  
It can be noticed that the addition of sorghum seed flour did not have a significant influence on the wheat flour dough's stability (Table 6).  
As the percentage of sorghum flour increased, the amplitude the width of the curve during dough formation increase, which suggests a higher elasticity of the dough, due to higher content of fat. This increase in fat content is due to sorghum seeds, with a positive influence on the dough.  
The increase of consistency (C2--the behavior of the gluten when heating the dough) reveal a higher resistance of dough as an effect of temperature. The increase in sorghum addition did not lead to changes in this parameter.  
In phase 3, the starch gel formation (at temperature 50-55 \({}^{\circ}\)C) the lowest C3 was observed for wheat flour. The difference in C3 results between wheat flour and mixture of wheat + 40% sorghum was 0.124 N\(\cdot\)m, so the influence on dough preparation recipe was low.  
The C4 parameter corresponds to the stability of the hot-formed gel. The lowest C4 was found for wheat flour (Table 6). The difference for C4 results between wheat flour and wheat flour + 40% sorghum was only 0.281 N\(\cdot\)m.  
The retrogradation stage of starch (C5) for the tested wheat flour and wheat-sorghum flour mixtures demonstrated similar differences as for C4 parameter.  
From those presented above, it can be determined that, with regard to their baking quality, the flour mixtures studied can be categorized as flours adequate for bakery products.  
The mixolab curves of the wheat control sample and of all three mixtures of wheat and sorghum flour are shown in Figure 5.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **100\% Wheat** & **70\% Wheat Flour +** & **65\% Wheat Flour +** & **60\% Wheat Flour +** \\  & **Flour** & **30\% Sorghum Flour** & **35\% Sorghum Flour** & **40\% Sorghum Flour** \\ \hline Water Absorption (\%) & 58.2 \(\pm\) 0.06 a & 54.7 \(\pm\) 0.06 b & 53.4 \(\pm\) 0.1 c & 52.7 \(\pm\) 0.1 c \\ Stability (min) & 9.15 \(\pm\) 0.01 a & 8.69 \(\pm\) 0.01 c & 8.82 \(\pm\) 0.01 b & 8.51 \(\pm\) 0.01 d \\ Amplitude (Nm) & 0.097 \(\pm\) 0.001 c & 0.107 \(\pm\) 0.001 b & 0.109 \(\pm\) 0.001 b & 0.124 \(\pm\) 0.002 a \\ C1 & 1.098 \(\pm\) 0.01 a & 1.093 \(\pm\) 0.01 a & 1.097 \(\pm\) 0.01 a & 1.097 \(\pm\) 0.01 a \\ C2 & 0.462 \(\pm\) 0.01 a & 0.469 \(\pm\) 0.01 a & 0.474 \(\pm\) 0.01 a & 0.483 \(\pm\) 0.01 a \\ C3 & 1.924 \(\pm\) 0.01 c & 1.995 \(\pm\) 0.01 b & 2.040 \(\pm\) 0.01 a & 2.048 \(\pm\) 0.02 a \\ C4 & 1.809 \(\pm\) 0.01 d & 1.939 \(\pm\) 0.01 c & 1.998 \(\pm\) 0.02 b & 2.090 \(\pm\) 0.03 a \\ C5 & 3.049 \(\pm\) 0.01 c & 3.139 \(\pm\) 0.01 b & 3.138 \(\pm\) 0.02 b & 3.233 \(\pm\) 0.02 a \\ \hline \hline \end{tabular} Note. a.b The results are expressed as mean \(\pm\) standard deviation. Different letters in the same row indicate significant differences (\(p<0.05\)).  
\end{table}
Table 6: Rheological characteristics of flour mixtures and wheat flour.