Effects of various physical pretreatments and dextranase on the structure and physicochemical properties of porous sweet potato starch: a comparative study

Porous starch, a modified starch containing numerous micropores, has significant application potential due to its excellent absorbency. However, traditional enzymatic hydrolysis methods exhibit low efficiency. This study improved porous starch production from sweet potato by combining physical pretreatments (ultrasonic, moist heat, microwave) with dextranase hydrolysis. Among these, microwave-assisted enzymatic hydrolysis rapidly created porous starch with a compact pore structure without introducing new chemical groups. The resulting starch exhibited increased solubility (5.22%) and decreased swelling power (6.92%), enhancing its physicochemical characteristics. Remarkably, oil absorption capacity rose from 51.02% to 102.79%, and water absorption improved from 58.63% to 120.40%, attributed to increased porosity and specific surface area. These advancements offer an efficient method to produce sweet potato porous starch with superior absorption properties, presenting promising opportunities for application in the food and pharmaceutical industries.