# Enhancement of Wheat Flour and Dough Properties by Non-Thermal Plasma Treatment of Wheat Flour
## 4 Conclusions  
The key findings of the presented research are:  
* Due to the non-thermal nature of the generated plasma, the moisture content of treated wheat flour (type 550 and 1050) does not change significantly and stays close to 14%. * Three minutes was identified as an optimal NTP treatment time for all test cases, with which the changes in visco-elastic properties reached their maximum values. * Increase in the hydration properties (WHC and WBC) of wheat flour with an increase in NTP treatment time was determined. A maximum increase in WBC value of approximately 6% was observed for the NTP treatment time of 3 min. Longer treatment times resulted in decreases in WBC values. * Rheological analysis demonstrated the effectiveness of NTP in enhancing the visco-elastic properties of wheat dough. In the case of doughs formed using NTP-treated flour type 550, the visco-elastic properties, i.e., the storage (G\({}^{\prime}\)) and loss (G\({}^{\prime\prime}\)) moduli, increased, on average, by more than 100%. A maximum increase of 130% was detected for the dough made with flour treated with NTP for three minutes. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Increase (\%)** & **G\({}^{\prime}\)** & **G\({}^{\prime\prime}\)** \\ \hline @ 10 \({}^{\circ}\)C vs. UT & 25–53\% & 20–44\% \\ @ 20 \({}^{\circ}\)C vs. UT & 26–51\% & 17–43\% \\ @ 30 \({}^{\circ}\)C vs. UT & 80–121\% & 71–105\% \\ @ 40 \({}^{\circ}\)C vs. UT & 81–120\% & 75–110\% \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Increase in G\({}^{\prime}\) and G\({}^{\prime\prime}\) values for the doughs produced with plasma-treated flour samples (presented as minimum-to-maximum increase in comparison to doughs produced with untreated flour samples) as a function of environmental temperature. * For doughs produced with flour type 550 treated by NTP for three minutes, the yield and the flow point increased by 75 and 51%, respectively. * Based on the rheological measurements, NTP treatment was found to be effective in enhancing the visco-elastic properties G\({}^{\prime}\) and G\({}^{\prime\prime}\) of the flour type 550 samples (the G\({}^{\prime}\) and G\({}^{\prime\prime}\) values more than doubled), while for the type 1050 samples its influence was less noticeable. * The amount of treated flour, i.e., the extent of reactor volume filling, was identified as an important factor that significantly influences the effects of the NTP treatment of flour. Based on the hydration and rheological properties of the obtained doughs, it was concluded that for the presented reactor the optimal fill is in the range of 6 to 13% of the reactor volume. * A wheat flour mass of 150 g (equivalent to 6% of the reactor volume) was identified as an optimal mass for the present geometry for which the maximum enhancement in rheological properties (type 550: G\({}^{\prime}\geq\)150%, G\({}^{\prime\prime}\geq\)200%; type 1050: G\({}^{\prime}\) = 40% and G\({}^{\prime\prime}\) = 30%) was observed. * Environmental (air) temperature has a significant effect on the visco-elastic properties of doughs produced with NTP-treated flour, indicating the importance of air temperature on plasma formation. The biggest difference (>100%) was noticed when the air temperature changed from 20 \({}^{\circ}\)C to 30 \({}^{\circ}\)C. Further increase did not contribute significantly to dough rheological properties. * Analysis of variance (ANOVA) was performed in order to detect statistical differences among the samples due to NTP treatment. In the case of type 550 flour, the \(p\)-value was less than 0.05, confirming the existence of significant statistical difference and thus an influence of the non-thermal plasma treatment on flour properties. On the other hand, in the case of flour type 1050, the \(p\)-value was greater than 0.05, leading to the conclusion that no significant statistical difference existed between the untreated and treated samples. NTP treatment has the potential to replace the use of chemicals in order to enhance the functional properties of wheat dough.