Effect of legume proteins on the structure and digestibility of wheat starch-lauric acid complexes

The effect of legume proteins (soy protein (SP), chickpea protein (CP) and peanut protein (PP)) on the properties of wheat starch-lauric acid (WS-LA) system and its intrinsic mechanism were investigated. RVA, digestion experiment and TGA results showed that legume proteins prompted the viscosity peak formation during cooling stage and increased anti-digestion and thermal stability of WS-LA system. FT-IR, Raman, XRD and 13 C NMR results indicated that legume proteins improved the long-range and short-range ordering degree and single-helix structure of WS-LA system. SP had greater influence on the properties of WS-LA system than that of CP and PP. Proteins with high solubility, emulsifying properties and β-sheet content were conducive to starch-based complexes formation. Molecular dynamics simulation results indicated that major forces for WS-LA-SP formation were hydrogen bonding and van der Waals forces. This study offered crucial information on starch-fatty acid-protein complexes formation for proteins selection in starch-based products development.