Physicochemical Properties and Digestion of Lotus Seed Starch under High-Pressure Homogenization

Lotus seed starch (LS), dispersed (3%, w/v) in deionized water was homogenized (0-180 MPa) with high-pressure homogenization (HPH) for 15 min. The effects of HPH treatment on the physicochemical properties of the starch system were investigated. The properties were affected by HPH to various extents, depending on the pressure. These influences can be explained by the destruction of the crystalline and amorphous regions of pressurized LS. The short-range order of LS was reduced by HPH and starch structure C-type was transformed into B-type, exhibiting lower transition temperatures and enthalpy. The LS absorbed a great deal of water under HPH and rapidly swelled, resulting in increased swelling power, solubility and size distribution. It then showed broken porcelain-like morphology with reduced pasting properties. Digestion of pressurized LS complex investigated by a dynamic in vitro rat stomach-duodenum model showed higher digestion efficiency and the residues exhibited gradual damage in morphology.