A comprehensive review on chemical modifications of plant proteins: mechanisms, influencing factors, and impacts on structural, functional, and nutritional properties

Plant proteins have gained increasing attention due to their sustainability and nutritional benefits, yet their complex structures and limited functional properties restrict their broader use in food systems. Chemical modification has emerged as an effective strategy to regulate protein conformation and functionality, but a comprehensive understanding of different modification mechanisms and their implications is still lacking. This review provides a systematic overview of five major chemical modification approaches-pH-shifting, glycosylation, phosphorylation, acylation, and deamidation-with emphasis on their underlying mechanisms and key influencing factors. In addition, recent findings on how these modifications alter secondary and tertiary structures and thereby enhance solubility, emulsifying, foaming, and gel properties are critically summarized. Finally, the review highlights the nutritional implications, challenges, and future perspectives of chemical modifications. Chemical modifications of plant proteins are mainly pH-shifting and glycosylation modifications. Glycosylation, phosphorylation, acylation, and deamidation modifications can be affected by a variety of factors compared to pH-shifting modification. Chemical modifications mainly alter the secondary and tertiary structure of plant proteins. Chemical modifications can significantly improve the functional properties (solubility, emulsifying, foaming, and gel properties) of plant proteins under specific conditions.