## 3 Results
### Modifications in the Structural and Thermal Properties of Flour Segments Due to PEF Treatment
#### 3.2.4 Starch Short-Range Ordered Structure  
FTIR spectroscopy was used to evaluate the short-range molecular order of starch in segment samples, which were collected from PEF-treated oat flour. The data gathered was useful in estimating the properties of the double helices structure in starch [22]. Spectral deconvolution and peak analyses around 1019 and 1042 cm\({}^{-1}\) were found to be valuable in obtaining characteristic data on the amorphous and crystalline structures of starch, respectively.  
All flour segment samples displayed corresponding crystalline and amorphous peaks on the regions around 1039-1050 cm\({}^{-1}\) and 1016-1027 cm\({}^{-1}\), respectively, when oat flour was treated at low (\(\sim\)2 kV/cm) and high (\(\sim\)4 kV/cm) intensity electric field strengths (Table 3). Relevant FTIR peaks for most flour segments were found to be situated around 1042 and 1019 cm\({}^{-1}\). However, SS1 obtained from PEF-treated oat flour at 4.2 kV/cm, 438 kJ/kg revealed a distinct shift in the positions of its relevant peaks (4-C, Table 3). FTIR peaks associated with its crystalline and amorphous structures were identified to be positioned at 1050 cm\({}^{-1}\) and 1027 cm\({}^{-1}\), respectively. The same sample (4-C, SS1) also displayed the lowest recorded wavelength ratio in terms of peak height values amongst the samples tested (Table 3). On the other hand, the rest of the segment samples did not manifest significant difference in its FTIR ratio compared to Control.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Treatment**} & \multirow{2}{*}{**Flour Segment**} & **Peak Positions** & **Peak Height Ratio** \\  & & **(cm\({}^{-1}\))** & **(1042/1019 *)** \\ \hline Control & SS1 & 1042, 1019 & 1.08 \(\pm\) 0.10 \({}^{\text{ab}}\) \\ No PEF & SS2 & 1040, 1019 & 1.06 \(\pm\) 0.22 \({}^{\text{a}}\) \\  & SS3 & 1042, 1019 & 1.15 \(\pm\) 0.32 \({}^{\text{a}}\) \\ \hline  
kJ/kg & SS3 & 1044, 1019 & 1.00 \(\pm\) 0.08 \({}^{\text{a}}\) \({}_{\text{AB}}\) \\ \hline \hline \end{tabular}  
* Peaks around 1039–1050 and 1016–1027 represent the crystalline region and amorphous region of starch, respectively.
* Wavenumbers vary depending on the exact peak position in the FTIR spectra. Means sharing the same lowercase letters in superscript indicate no significant difference (\(p>0.05\)) between treatments from the same flour segment based on post hoc [PERSON]’s HSD test (SS1–Control vs. 2-A vs. 2-B vs. 3-C vs. 4-A vs. 4-B vs. 4-C). Means sharing the same uppercase letters in subscript indicate no significant difference (\(p>0.05\)) between mean values of different flour segments within a treatment based on post hoc [PERSON]’s HSD test (Control–SS1 vs. SS2 vs. SS3).  
\end{table}
Table 3: Ratio of the crystalline to amorphous regions of starch in three different flour segments that were collected after PEF treatment of oat flour.  
Evaluation of three separate segment samples within a treatment showed variation in peak height ratio, particularly after PEF treatment of oat flour at high specific energy input level of 421-438 kJ/kg. Looking closely within the treatment, SS1 from PEF-treated oat flour at 421-438 kJ/kg exhibited the lowest peak height ratio compared to SS2 and SS3 (2-C and 4-C, Table 3). On the other hand, segment samples (SS1, SS2, and SS3) within Control and other PEF-treated oat flour did not manifest noteworthy variation of its 1042/1019 peak height ratio.