Structures and Adsorption Properties of Porous Cassava Starch via Ball Milling and Ultrasound‐Assisted Enzymatic Hydrolysis

ABSTRACT The porous cassava starch was prepared through the synergistic actions of ball milling and ultrasound‐assisted enzymatic hydrolysis. The surface of starch granules became rough, forming grooves and even developing porous structures. Additionally, the size of the starch granules decreased, and the spherulitic structures were damaged. The melting peak temperature of the porous starch enhanced, while the melting enthalpy and crystallinity significantly decreased. The carbon element (C) content decreased whereas the oxygen element content (O) increased. The amylose content and hydrolysis degree enhanced, while the amylopectin content reduced. The solubility of the porous starch improved, but the swelling declined. The oil absorption, water absorption, and methylene blue (MB) adsorption capacities enhanced. The MB adsorption behavior of the starch samples was better described by the pseudo‐second‐order kinetic model and the Langmuir isotherm model. The MB adsorption process of the modified starch demonstrated an exothermic characteristic.