Regulation in protein hydrophobicity via whey protein-zein self-assembly for improving the techno-functional properties of protein

This work aims to verify the feasibility of improving protein function by regulating its hydrophobicity and reveal the relationship between structure and function. Whey protein (WP) and zein were the source of hydrophilic and hydrophobic polypeptide chains to prepare complex proteins (CPs) with much different structure and function. The results showed that the water- and oil-holding capacities, emulsifying properties and gel properties of CPs can be significantly improved via changing WP-zein ratio. All these can be attributed to the changes in protein hydrophobicity, which not only regulated the binding strength of protein to water and oil, but also modified their molecular structure (surface characteristics, availability of free thiols, α-helix, β-sheet, random coil and the formation of disulfide bonds). Notably, optimal protein hydrophobicity varies greatly among different functional properties. Overall, the techno-functional properties of protein can be improved via tuning its hydrophobicity, which may provide novel sights in protein modification. [Display omitted] •Protein hydrophobicity can be regulated via changing whey protein (WP)-zein ratio.•Zein interacts with WP to form stable complex and changes protein conformation.•Increase in WP ratio transforms main force from non-covalent bonds to covalent bonds.•Techno-functional properties of protein can be improved via tuning its hydrophobicity.•Optimal protein hydrophobicity varies greatly among different functional properties.