The Impact of Glycation on Protein Digestibility

ABSTRACT Glycation is a non‐enzymatic reaction between reducing sugars and amino groups in proteins and commonly occurs during food processing and storage. Structural modifications induced by glycation can reduce enzyme accessibility and hinder proteolytic activity. In particular, lysine residues are important targets for both glycation and digestive enzymes. Current evidence presented in this review indicates that glycation alters protein digestibility and lysine availability, although the extent of these effects depends on the degree and chemical nature of glycation, protein source, and processing conditions. Nevertheless, reduced protein digestibility or amino acid availability observed in vitro does not necessarily translate into impaired overall protein utilization in vivo. Human studies indicate that adequate total protein intake and sufficient availability of other indispensable amino acids may mitigate the effects, for example, on muscle protein synthesis. Major knowledge gaps remain regarding the relationship between specific glycation structures, their localization within proteins and digestion outcomes, as well as regarding digestibility of plant‐based proteins. Future research should combine advanced analytical approaches with physiologically relevant digestion models, particularly for plant‐based food, to elucidate structure‐digestibility relationships and clarify when glycation‐induced modifications become nutritionally relevant. An interdisciplinary approach is necessary to achieve a more comprehensive understanding of the nutritional consequences of glycation.