Paste structure and rheological properties of lotus seed starch-glycerin monostearate complexes formed by high-pressure homogenization.

Starch-lipid complexes were prepared using lotus seed starch (LS) and glycerin monostearate (GMS) via a high-pressure homogenization (HPH) process, and the effect of HPH on the paste structure and rheological properties of LS-GMS was investigated. Rapid Visco Analyser (RVA) profiles showed that HPH treatment inhibited the formation of the second viscosity peak of the LS-GMS paste, and the extent of this change was dependent on the level of homogenized pressure. Analysis of the size-exclusion chromatography, light microscopy, and low-field 1 H nuclear magnetic resonance results revealed that high homogenized pressure (70-100MPa) decreased molecular weight and size by degrading the branch structure of amylopectin; however, intact LS-GMS granules can optimize the network structure by filler-matrix interaction, which causes free water to transition into immobile water in the starch paste. The steady-shear results showed that the LS-GMS pastes presented non-Newtonian shear-thinning behavior, with higher homogenized pressure producing a smaller hysteresis loop area. During the oscillation process, the LS-GMS pastes prepared at 100MPa exhibited the lowest loss tangent values in all the complexes, indicating a stronger resistance to vibration.