Rational mutual interactions in starch-lipid-chlorogenic acid ternary systems enable formation of ordered starch structure for anti-digestibility during hot-extrusion 3D printing: Based on the nonlinear rheology and molecular simulation

In this study, nonlinear rheology and molecular simulation were introduced to unravel the molecular interactions among wheat starch (WS), linoleic acid (LA) and chlorogenic acid (CGA) during hot-extrusion 3D printing (HE-3DP), and their key structural details and digestibility were relevantly discussed. The combined results showed the interactions led to weakened shear thinning behavior and increased contribution of strain hardening. Moreover, LA induced the WS cavity through hydrophobic interactions to form single helix, while CGA facilitated the connection of WS-LA helix through hydrogen bonding, resulting in the formation of unstable aggregated structures. Notably, the disappearance of type II complex peaks and increased ξ showed less dense ordered structures in WS-LA-CGA complex. During digestion process, the stable starch-LA helix could reduce the binding energy with amylase, while the dissociated CGA not only further lowered the binding energy, but also served as an enzyme inhibitor via hydrogen bonds interaction, thereby enhancing the anti-digestibility.