Mechanistic insights into the improved properties of mayonnaise from the changes in protein structures of enzymatic modification-treated egg yolk

Heat treatment is an important step in mayonnaise production but can affect the quality of mayonnaise because thermal treatment can accelerate oil droplet coalescence. To resolve this issue, in this study, enzymatically modified egg yolks were applied to produce mayonnaise. Egg yolk hydrolyzed with 0.2% neutral protease could effectively produce mayonnaise with superior heat stability, and this effect was attributed to enzymatic modifications that increased the degree of amino acid ionization, the overall hydrophilicity and the ability to adsorb proteins. Moreover, electrophoresis and FT-IR results showed that the enzymatically modified egg yolk proteins had a smaller molecular weight and more flexible structure, which could also favor the improved properties. The study elucidated why mayonnaise prepared by enzymatic modification-treated egg yolk has better thermal stability.