# Enhancement of Wheat Flour and Dough Properties by Non-Thermal Plasma Treatment of Wheat Flour
## 3 Results and Discussion  
### Effects of Non-Thermal Plasma Treatment Time on Wheat Flour and Dough Properties  
#### 3.1.1 Hydration Properties of Flour  
The variation in the moisture content of wheat flour samples with treatment time (1, 3 and 5 min) is shown in Figure 3. It was determined five times per sample, based on which the standard deviation was calculated. The obtained results showed a general trend towards a decrease in moisture content with respect to treatment duration. A low moisture content (i.e., 12-15%) keeps the flour stable at room temperature. A decrease in the moisture content of wheat flour is also connected to change in physically \"bounded\" water amount and has a decisive influence on rheological, physical and chemical properties. There are certain indications in the literature that a lowering of moisture content results in mechanical rigidity and the complex viscosity of a dough [53; 54], which characteristics are directly related to the stronger visco-elastic properties of wheat dough.  
The dependence of the WHC on treatment time (1, 3 and 5 min), as shown in Figure 4a, was determined five times per sample, based on which the standard deviation was calculated. The WHC of the untreated sample was 168% \(\pm\) 5% water retained per one gram of flour, which increased slowly with treatment time to reach its maximal value of 173% \(\pm\) 4%, corresponding to 3 min of plasma treatment time. This corresponds to the finding shown in Figure 3, i.e., that as the moisture content decreases with treatment time, the water-holding ability of the flour increases. Still, no firm conclusion could be drawn at this point, as the standard deviation of this measurement was high compared to the observed change in WHC values.  
The WBC dependence on treatment time, shown in Figure 4b, was also determined using five measurements per sample. The WBC level for untreated flour was measured to be 73% \(\pm\) 3%. The maximum increase, just under 80% \(\pm\) 1%, was observed for the NTP treatment of 3 min. Longer treatment resulted in decrease in WBC. Higher hydration values (WHC, WBC) were observed in the case of the untreated type 1050 flour (92% \(\pm\) 1%) due to its higher protein content. However, no significant differences in the tendencies relating to hydration properties between the flour types 550 and 1050 were observed; thus, these were not separately presented.  
Both the WHC and WBC of the tested wheat samples (types 550 and 1050) increased with plasma treatment time. The treatment time of three minutes resulted in a maximum enhancement (7% \(\pm\) 3%) of the WBC of type 550 flour. It is postulated that this increase in WHC can be due to the hydrolytic depolymerisation of starch [41]. In addition, the surface modifications (increase in surface energy due to the addition or exchange of functional groups [55; 56]) of flour particles due to the plasma treatment could be another important factor that influences the hydration properties of flour. It has also been reported in the  
Figure 3: Change in the moisture content of wheat flour (type 550) as a function of NTP treatment time.  
literature that plasma treatment results in a decrease in water contact angle, leading to higher water permeability, which results in an increased affinity of flour particles towards water [57].