Zein-glutelin interactions and physicochemical properties of protein complex during corn post-harvest ripening process

Proteins in corn mainly consist of zein and glutelin, existing in the form of complexes. Corn post-harvest ripening has a significant impact on the zein-glutelin interaction, which affects the structure and properties of protein complex. The changes in interaction, structure and physicochemical properties of zein-glutelin complex during corn post-ripening were investigated. The structural stability of the zein-glutelin complex was mainly maintained by hydrophobic interactions, hydrogen bonds, and disulfide bonds. After post-ripening at 15 °C for 45 days and 25 °C for 30 days, the complex protein subunits degraded, the α-helix transformed into β-sheet, and the hydrophobic interactions and disulfide bonds increased. Furthermore, both more ordered β-structure at 15 °C and higher disulfide bond at 25 °C formed protein rigid aggregates with a uniform and orderly distribution, which suggested a stronger zein-glutelin interaction, resulting in lower solubility and higher water- and oil-holding capacity of the protein complex.