Food
allergens are closely related to their gastrointestinal digestion fate, but the changes in food
allergens during digestion and related mechanisms are quite complicated. This review presents in detail digestion models for predicting allergenicity, the fates of food
allergens in oral, gastric and duodenal digestion, and the applications of digestomics in mapping
IgE-binding
epitopes of digestion-resistant
peptides. Moreover, this review highlights the structure-activity relationships of food
allergens during gastrointestinal digestion. Digestion-labile
allergens may share common structural characteristics, such as high flexibility, rendering them easier to be hydrolyzed into small fragments with decreased or eliminated allergenicity. In contrast, the presence of
disulfide bonds, tightly
wound α-helical structures, or hydrophobic domains in food
allergens helps them resist gastrointestinal digestion, stabilizing
IgE-binding
epitopes, thus maintaining their sensitization. In rare cases, digestion leads to increased allergenicity due to exposure of new
epitopes. Finally, the action of the food matrix and processing on the digestion and allergenicity of food
allergens as well as the underlying mechanisms was overviewed. The food matrix can directly act on the
allergen by forming complexes or new
epitopes to affect its gastrointestinal digestibility and thereby alter its allergenicity or indirectly affect the allergenicity by competing for enzymatic cleavage or influencing gastrointestinal pH and microbial flora. Several processing techniques attenuate the allergenicity of food
proteins by altering their conformation to improve susceptibility to degradation by digestive
enzymes. Given the complexity of food components, the food itself rather than a single
allergen should be used to obtain more accurate data for allergenicity assessment. PRACTICAL APPLICATION: The review article will help to understand the relationship between food protein digestion and allergenicity, and may provide fundamental information for evaluating and reducing the allergenicity of food
proteins.