## 3 Results
### Modifications in the Structural and Thermal Properties of Flour Segments Due to PEF Treatment  
#### 3.2.1 Particle Size and Volume Distribution  
Table 2 revealed that segments from Control and PEF-treated oat flour exhibited a range of particle sizes, which were dictated by the processing parameters involved during PEF treatment and the location from which samples were collected (i.e., Solid Segment 1/SS1, Solid Segment 2/SS2 or Solid Segment 3/SS3). These segment samples also exhibited either a unimodal or multimodal size distribution with well-defined peaks and shoulders (Figure 3). \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & & \multicolumn{3}{c}{**Proportion of Starch Fractions \#**} & \multicolumn{3}{c}{**Estimated Kinetic Parameters of**} \\ \cline{3-8}
**PEF Process** & & & & & \multicolumn{2}{c}{**In Vitro** Starch Digestibility **\#**} \\ \cline{3-8}
**Parameters** & & & & & \(G_{0}\) & \(G_{f}\) & \(k\) \\  & & **RDS (\%)** & **SDS (\%)** & **RS (\%)** & **(mg/mL** & **(mg/mL** & **(\(\times 10^{-2}\)** \\  & & & & & **Digest)** & **Digest)** & **min\({}^{-1}\))** \\ \hline Control & No PEF & 14.83 \(\pm\) 0.41 b & 8.50 \(\pm\) 1.05 a & 77.17 \(\pm\) 0.41 bc & 0.21 \(\pm\) 0.01 & 0.96 \(\pm\) 0.01 & 3.83 \(\pm\) 0.25 \\
2.2 kV/cm, & 2-A & 14.17 \(\pm\) 0.75 b & 8.17 \(\pm\) 0.75 ab & 78.00 \(\pm\) 0.63 b & 0.19 \(\pm\) 0.01 & 0.92 \(\pm\) 0.01 & 4.01 \(\pm\) 0.27 \\
53 kJ/kg & & & & & & & \\
2.2 kV/cm, & 2-B & 13.33 \(\pm\) 1.03 b & 8.67 \(\pm\) 1.86 a & 78.00 \(\pm\) 1.10 b & 0.20 \(\pm\) 0.02 & 0.91 \(\pm\) 0.02 & 3.46 \(\pm\) 0.31 \\
21 kJ/cm, & & & & & & & \\
421 kJ/kg & 2-C & 20.00 \(\pm\) 0.63 a & 6.50 \(\pm\) 1.05 ab & 73.17 \(\pm\) 1.17 d & 0.56 \(\pm\) 0.02 & 1.15 \(\pm\) 0.02 & 3.68 \(\pm\) 0.47 \\
4.5 kV/cm, & & & & & & & \\
52 kJ/kg & & & & & & & \\
4.3 kV/cm, & & & & & & & \\
216 kJ/kg & & & & & & & \\
4.2 kV/cm, & & & & & & & \\
438 kJ/kg & & & & & & & \\ \hline \hline \end{tabular} \# Data is presented as mean \(\pm\) standard deviation (\(n=6\)). Means sharing same lowercase letters in subscript within the same column are not significant different (\(p>0.05\)) based on post hoc [PERSON]’s HSD test. ## Data is presented as estimated kinetic parameter \(\pm\) standard error of the estimated value based on the fractional conversion model (Equation (4)).  
\end{table} 
Table 1: Calculated proportions of readily digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) and the estimated kinetic parameters of _in vitro_ starch digestibility for PEF-treated oat flours. Evaluation of flour segment data showed that SS1 from PEF-treated oat flour at 421-438 kJ/kg exhibited the largest particle size (2-C and 4-C, Table 2). SS1 also displayed the greatest extent of modification in terms of overall particle size. More specifically, SS1 samples demonstrated up to an eight-fold increase in particle size after oat flour PEF treatment at 421-438 kJ/kg (2-C and 4-C, Table 2). A further significant increase in size was also detected when the electric field strength was increased from 2.1 to 4.2 kV/cm (2-C and 4-C, Table 2). On the other hand, only a two- to three-fold increase in size was displayed by its corresponding SS2 samples (4-C, Table 2). In contrast, the overall impact of oat flour PEF treatment to SS3 samples was not evident based on the comparable size profiles of the samples (Table 2).