Multiscale engineering of deep eutectic solvent-plasticized starch-based carriers: From molecular interactions to...

To further improve the problems of high cost of traditional gelatin capsules and poor mechanical properties of pure starch capsules, this study made full use of biomass-derived functional food materials and successfully prepared an economical, green, and performance-enhanced intelligent responsive composite starch capsule (film). The results showed that the tensile strength of Betaine-glycerol/hydroxypropyl starch-gelatin (B-G/HPS-Ge) was increased by 6.09%, and the elongation at break was increased by 28.77%, compared with Glycerol/hydroxypropyl starch-gelatin (G/HPS-Ge). Differential Scanning Calorimetry (DSC) showed that plasticizer additions lowered the T_g and T_m of the Hydroxypropyl starch-gelatin (HPS-Ge) film, demonstrating successful plasticization. The loss on drying, disintegration time, and friability of B-G/HPS-Ge capsules all met the standards of the Chinese Pharmacopoeia. The pH-responsive capsules showed obvious response effects at different pH values. Reduced density gradient (RDG) analysis indicated a more complex and competitively stronger hydrogen-bond network in the B-G/HPS-Ge system. The interaction force of B-G/HPS-Ge (-262.49 kJ/mol) was significantly lower than that of G/HPS-Ge (-126.47 kJ/mol), indicating that there was a stronger interaction between B-G and the starch matrix. It provided new ideas for the development of new intelligent responsive starch-based edible carriers.