Post-translational modifications of proteins and their effect on techno-functional properties for food applications

Post-translational modifications (PTMs), including glycosylation, phosphorylation, acetylation, and methylation, are protein modifications that involve the covalent addition of functional groups after their biosynthesis. They are critical factors for protein structure and function, influencing not only biological activity but also techno-functional properties. Their relevance in food proteins is increasingly recognized as the demand for sustainable proteins grows, particularly for recombinant proteins produced via precision fermentation. This review provides an overview of the most important PTMs and discusses their influence on techno-functional properties of proteins such as solubility, emulsification, gelation, and foaming. Especially hydrophilic functional groups (e.g., glycans and phosphate) often enhance solubility while hydrophobic groups (e.g., fatty acids) tend to reduce it. Hydrophobic interactions also have a profound effect on functionality. Further, methods to modify PTMs chemically, enzymatically, or physically are discussed and analytical techniques for their detection are critically reviewed. By bringing together insights from biology, food science, and protein engineering, this review outlines how targeted PTM control could improve functionality in alternative proteins for food, cosmetic, or pharmaceutical use. This review can serve as a guide on how to modify particularly novel sustainable or recombinant proteins in a targeted manner to tailor their functionality and extend their application areas.