Interactions and structural properties of zein/ferulic acid: The effect of calcium chloride

Zein is potential in encapsulating and delivering polyphenols in food industry. Our study investigated the interaction mechanisms and structural changes of the interaction between ferulic acid (FA) and zein under different CaCl₂ concentrations. Addition of CaCl₂ resulted in amino acids micro-environment and structural changes of zein and zein/FA complex, which was dependent on different CaCl₂ concentrations. At 0.5 mol/L CaCl₂ concentration, zein/FA exhibited spherical particles with rough surfaces. Fourier transform infrared analysis showed the decrease of α-helix and β-sheets contents accompanied by the increase of β-turns and unordered coil contents. Molecular dynamics simulation demonstrated FA interacted with zein mainly through hydrogen bonds and hydrophobic force. These observations might contribute to the decreased surface hydrophobicity and digestibility of zein. Results provided a better understanding of the interaction between zein and other molecules, which might be helpful for the development of zein particles as functional materials to encapsulate and deliver bioactive compounds.