## 3 Results
### Modifications in the Structural and Thermal Properties of Flour Segments Due to PEF Treatment
#### 3.2.3. Starch Long-Range Ordered Structure of Flour Segments  
Modifications in the long-range ordered structure of flour segments were studied based on the alterations observed in X-ray diffractograms (XRD). XRD data of each flour segment sample obtained from Control and selected PEF-treated oat flour are presented in Figure 6. SS1, SS2, and SS3 from Control displayed the typical A-type pattern expected of cereal starches. More specifically, peaks at 15.1\({}^{\circ}\), 23\({}^{\circ}\), doublet peak at 17.1\({}^{\circ}\) and 18.2\({}^{\circ}\), and a small peak at 20\({}^{\circ}\) were recorded. Similarly, SS1, SS2, and SS3 obtained from PEF-treated oat flour processed at 52-218 kJ/kg displayed comparable XRD patterns with Control (data not shown). On the contrary, XRD patterns of SS1 collected from PEF-treated oat flour at 421-438 kJ/kg (2-C and 4-C) displayed weakened or loss of some peaks in comparison  
Figure 5: Scanning electron micrographs of selected Solid Segment 3 (SS3) samples from PEF-treated oat flour. SEM images are presented at 1000\(\times\) (rows 1 and 2) and 2000\(\times\) (row 3) magnifications. Yellow arrows point to the intact/undeformed granules of starch indicating that PEF treatment of oat flour at 2.1 kV/cm, 421 kJ/kg (2-C) and 4.2 kV/cm, 438 kJ/kg (4-C) did not cause significant impact on starch granules comprising SS3 samples.  
to Control. In particular, peaks at 15.1\({}^{\circ}\), 17.1\({}^{\circ}\), 18.2\({}^{\circ}\), and 23\({}^{\circ}\) (20) appeared to have been altered after PEF treatment of oat flour (Green dots, Figure 6). Moreover, a new peak at 13\({}^{\circ}\) (20) became apparent for these same samples after PEF treatment of oat flour at 421-438 kJ/kg (Red dots, Figure 6).  
Based on the XRD pattern, the percent relative crystallinity of each segment was determined to evaluate any alterations in its crystallinity properties as a consequence of oat flour PEF treatment. Considering all the segments evaluated in this study, the percent  
Figure 6: X-ray diffractograms and percent relative crystallinity (%RC) of flour segments collected from PEF-treated oat flour at 418–484 kJ/kg. The %RC values are displayed as mean \(\pm\) standard error of mean (\(n=3\), collected and pooled from 24–34 independent samples). Means sharing the same lowercase letters in superscript indicate no significant difference (\(p<0.05\)) between treatments obtained from the same segment (e.g., 2-C, SS1 vs. SS2 vs. SS3). Means sharing the same uppercase letters in subscript indicate no significant difference (\(p<0.05\)) between flour segments obtained from different treatments (e.g., SS1, Control vs. 2-C vs. 4-C). Green dots direct to the modification of specific peaks due to PEF treatment. Red dots highlight the new peaks observed in flour segments collected from PEF-treated oat flour.  
relative crystallinity of samples ranged from 10.58-19.17%. SS1 collected from PEF-treated oat flour at 52-218 kJ/kg did not display significant change in percent relative crystallinity in comparison to Control (data not shown). However, SS1 from PEF-treated oat flour at 421-438 kJ/kg revealed a 20-34% reduction in percent relative crystallinity in comparison to SS1 from Control (%RC, Control, 2-C, and 4-C, Figure 6).