Pulsed electric field treatment of oat and barley flour: Influence on enzymes, non-starch polysaccharides, dough rheological properties and application in flat bread

Abstract

This study examined the effects of pulsed electric field (PEF) treatment on enzymes, non-starch polysaccharides, and bread making potential of oat and barley flour. Enzymes activity, microstructure, β-glucans extractability, molecular weight (Mw) and structure of non-starch polysaccharides, dough rheology and flat bread properties were determined. An exponential decay model explained better the residual activity of oat β-glucanase across electric field intensity than barley β-glucanase. PEF treatment of flour at 12 kV/cm for 162 ms significantly reduced β-glucanase activity (40.2–76.5%) while increased the concentration of total β-glucans (33.5%) and water-extractable arabinoxylans (36–41%). Mw of linear β-d-glucans decreased (9%) while Mw of branched arabinoxylans increased (6–33%). Scanning electron microscopy showed changes in microstructure of barley proteins. Blending wheat flour (70%) with oat or barley flour (30% weight) after PEF treatment enhanced gluten aggregation energy (29–19%) and breakdown viscosity (18–43%) of dough, as well as increased β-glucans content (21–32%) but reduced specific volume (11–24%). The findings of this study provide a comprehensive insight into the PEF's potential for retarding enzymatic reactions and preserving integrity of cereal non-starch polysaccharides.