_applied_  
_sciences_  
_Article_  
Understanding the Mechanism of How Pulsed Electric Fields Treatment Affects the Digestibility and Characteristics of Starch in Oat Flour  
**[PERSON] 1,2,3\({}^{\text{(c)}}\), [PERSON] 1,3\({}^{\text{(c)}}\), [PERSON] 1\({}^{\text{(c)}}\), [PERSON] 3, [PERSON] 3,4 [PERSON] 3,4 and [PERSON] 1,3,*  
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gelatinise and increase the rate of starch digestion, where GI was estimated to rise beyond 78 [5]. In conjunction, a significant increase in the proportion of rapidly digestible starch (RDS) and reduction in resistant starch fraction (RS) were observed [7]. Acknowledging the fact that oat starch is sensitive to structural and physical changes during processing, novel food processing technologies that can maintain the low GI response of oat without triggering a significant increase in starch digestion rate is worth exploring.  
Pulsed electric fields (PEF) is an emerging processing technique that has been recently on the spotlight to be considered on starch-rich food products such as rice, wheat, potato, and pea starches [8; 9], as well as oat and sorghum flows [10; 11]. This is because PEF may offer a novel opportunity to alter the physicochemical and structural characteristics of starches [12], which may lead to changes in product functionality including the thermal, pasting, and starch digestibility properties [13; 14]. The extent of PEF treatment influence is dictated by the different process parameters applied, including the electric field strength, pulse shape, pulse width, pulse number, specific pulse energy, and frequency [15; 16]. Equally, the inherent properties of the food material (e.g., Type A, B, or C starch polymorph; fresh or pre-treated) prior to processing were also found to substantially determine the magnitude of PEF treatment effect and the modifications brought about on product functionality [9; 10]. In this context, if PEF can influence oat structure and properties, the impact of PEF on the release of glucose during gastrointestinal process becomes of particular interest. Previous study by [PERSON] et al. [9] showed that the effect of PEF treatment on the starch digestibility was found to be more pronounced in wheat (Type A, i.e., considerable increase in %RDS and decrease in % slowly digestible starches (SDS)) and potato (Type B, i.e., increase in %RDS, %RS and decrease in %RS) starches compared to that of pea starch (Type C, i.e., no changes in any starch fraction).  
This research aimed to understand the mechanism of how PEF treatment affects the starch digestibility of oat flour. In this study, oat flour was prepared using raw oats and it was then subjected to 2 h long simulated gastrointestinal process to estimate the rate of starch digestibility and evaluate the proportion of different starch fractions (RDS, SDS, and RS). Fractionating oat flour based on gravity was conducted after PEF treatment. Afterwards, systematic and thorough structural and physicochemical analyses were carried out for each segment of PEF-treated oat flour alongside a control (no PEF treatment). Modifications in particle size, volume distribution, morphological characteristics, long- and short-range ordered structures of starch, and thermal properties under PEF influence were analytically assessed. At the end of this study, a possible mechanism based on the physicochemical properties of each oat segment was postulated.