Microwave and whey protein synergistically regulate the formation of steadied starch-fatty acids-protein-VB1 complexes: Structure, mechanism, digestion, and VB1 release properties

This study is the first to incorporate water-soluble vitamin B 1 into a starch-fatty acid-protein ternary system, constructing a starch-lauric acid-protein-vitamin B 1 quaternary complex (MRS-LA-WP-VB 1 ) that enables VB 1 encapsulation and controlled release. Low-moisture, short-duration microwave pretreatment (700 W, 60 s) increased amylose content and altered starch surface hydrophilicity, thereby creating conditions favorable for the encapsulation of guest molecules. WP binds to starch through hydrogen bonds and electrostatic interactions and, in synergy with microwave pretreatment, enhances the structural order and stability of the system. LA and VB 1 primarily enter the helical cavity via hydrophobic interactions. Encapsulation efficiency measured after selective disruption by NaCl, urea, and SDS revealed that the hydrogen-bonding-to-hydrophobic interaction ratio shifted from 7:3 to 5:5 from binary to quaternary complexes. The MRS-LA-WP-VB 1 increased resistant starch (RS) by 35.93% and exhibited excellent controlled release under in vitro simulated digestion, extending VB 1 release to 11 h showing potential for small-intestinal sustained release.