The interaction mechanisms, and structural changes of the interaction between zein and ferulic acid under different pH conditions

Recently, studies on the interactions between zein and polyphenols have attracted an increasing attention. This study investigated the interaction mechanisms, and structural changes of the interaction between ferulic acid (FA) and zein under different pH conditions. Results indicated the interaction of FA with zein altered the secondary structure of zein and induced the conversion of alpha-helix and beta-sheet based on Fourier transform infrared spectroscopy analysis. Molecular docking results revealed the binding stability of zein with FA under alkaline condition (pH 9) was stronger than that under acidic and neutral conditions. Structural changes resulted in reduced surface hydrophobicity and -SH content, increased antioxidant activity of zein after pH alteration. Results demonstrated the change of pH was the vital factor affecting the binding affinity of zein to FA. This study might provide insight for the future studies about food proteins physicochemical stability and nutriceuticals bioavailability in vitro or in vivo.