Effect of Lactic Acid Bacteria Fermentation Agent on the Structure, Physicochemical Properties, and Digestive Characteristics of Corn, Oat, Barley, and Buckwheat Starch

This study modified corn, oat, barley, and buckwheat starches using a Henan-specific sourdough starter, revealing that the initial starch architecture governs differentiated functional transformations. Pore-dominant starches (corn/buckwheat) underwent “inside-out” enzymatic pathways—corn starch exhibited a 38.21% reduced particle size through pore expansion, with long amylopectin chain degradation forming thermally stable gels, establishing it as an ideal base for anti-staling sauces and frozen dough. Buckwheat starch demonstrated a 44% increased amylose content facilitated by porous structures, where post digestion double helix formation elevated the resistant starch (RS) content by 7%, achieving a significant 28.19% GI (Glycemic Index) reduction. Conversely, fissure-dominant starches (oat/barley) experienced “surface-inward” limited erosion—oat starch, constrained by surface cracks, showed amorphous region degradation and short-chain proliferation, accelerating glucose release and adapting it for rapid digestion products like energy bars. Barley starch primarily underwent amorphous zone modification, enhancing the pasting efficiency to provide raw materials for instant meal replacement powders.