Multicomponent molecular interactions governing 3D printing of starch-based foods: Mechanistic insights, structural...

Amid the rapid advancement of food 3D printing (3DP) technologies, starch become a widely used matrix due to its excellent processability, structural versatility, and nutritional modulation potential. However, most existing reviews have primarily focused on processing parameters and rheological properties, while systematic discussions on the multicomponent interactions and their molecular mechanisms during printing remain scarce. This review centers on starch-based systems, briefly introducing how diverse molecular forces, including hydrogen bonding, hydrophobic interactions, electrostatic forces, and covalent bonds between starch, proteins, lipids, and polyphenols, drive the formation of novel composite structural domains during 3DP. Interestingly, the formation of these new structural domains induced by 3DP plays a crucial role in modulating key printing properties of starch systems at multiple scales such as rheology, shape fidelity and interlayer adhesion. Furthermore, the review systematically elucidates the effects of these interactions on gel setting kinetics, emulsion stability, and complex network formation, and comprehensively summarizes their intrinsic mechanisms in enhancing enzymatic resistance, promoting resistant starch (RS) formation, and modulating glycemic response and intestinal probiotic effects. Overall, this review highlights the value of 3DP by bridging the molecular-level interactions between starch and multicomponent systems with the macroscopic nutritional functionality of composite structures through innovative cross-scale insights.