Molecular insights into the synergistic binding mechanism of flaxseed extract encapsulation within an alginate-fish gelatin matrix.

This study focused on the development of pH-responsive microcapsules for flaxseed (FE) extract using a synergistic sodium alginate-fish gelatin matrix. LC-MS characterization identified sinapic acid as the predominant phenolic acid in the extract. The spray-dried capsules achieved high encapsulation efficiency, exceeding 90%. At an optimal 1% of FE, the particles were uniform and spherical. The system demonstrated excellent controlled release, depending on pH conditions, which demonstrated the matrix stability. Under simulated gastrointestinal environment, the release was rapid and nearly complete showing high antioxidant potential at the end of the digestion and ensuring enhanced bio-accessibility. The molecular dynamic and docking simulation results indicated the presence of hydrogen bonds between the polymers' matrix and sinapic acid and secoisolariciresinol diglucoside (SDG), and proved interesting interaction energies between cargo-matrix and matrix-matrix. These computational findings offered molecular-level insight into the component interactions, supporting the high encapsulation efficiency and the observed release trends.