Model system analysis of wheat starch-soy protein interaction kinetics using polystyrene microspheres

The objective of this study was to identify the interaction of puroindoline and starch lipids with soy proteins when coupled to polystyrene microspheres. Manipulation and removal of wheat starch granule surface proteins and lipids may damage granule integrity and hinder studies of ungelatinized starch systems. Therefore, 5 μm polystyrene microspheres were used to evaluate the role of starch granule surface components on exogenous protein binding. Puroindoline, phospholipid, glycolipid and triglyceride were passively adsorbed to the surface of polystyrene microspheres. Binding assays using soy protein indicated that puroindoline-lipid coated microspheres adsorbed soy protein to a greater extent than did those coated with puroindoline alone. Phospholipids increased binding more than glycolipids and triglycerides.