Food Allergenicity Evaluation Methods: Classification, Principle, and Applications

Abstract

The incidence of food allergies is increasing annually, emerging as a significant global concern for food safety and public health. To prevent allergic reactions, patients are advised to avoid ingesting allergenic foods. However, completely avoiding contact with such foods in real life is often challenging. Therefore, the development of reliable allergenicity evaluation methods is essential to assist food allergy patients in avoiding exposure to allergenic foods. These evaluation methods include mass spectrometry-based methods, bioinformatics predictions, simulated digestion, enzyme-linked immunosorbent assays, cell-based models, and animal models. Each method operates on distinct principles and is suited for specific evaluation contexts. This review systematically summarizes the pathogenesis of food allergies and details the principles and practical applications of common allergenicity evaluation methods. By highlighting recent studies in food allergenicity evaluation, we aim to deepen the understanding of allergenicity assessment and offer an overview with perspectives on its enhancement.

Keywords: IgE-mediated allergy; allergenicity evaluation; epitope; food allergen; food allergy; immune responses.

Figure 1

Mechanisms for food allergen delivery. Allergens can migrate from the intestinal lumen to the subepithelial layer through various pathways: large soluble proteins mainly utilize M cell-mediated transcytosis and goblet cell-associated antigen passages (GAPs), or they are captured by CD103⁻CXCR1⁺ dendritic cells (DCs) located beneath the epithelial layer. Conversely, small-molecular-weight particles can directly enter enterocytes via absorption or permeate through intercellular spaces. Abbreviation: LP: lamina propria; APCs: antigen-presenting cells.

Figure 2

Mechanisms of IgE-mediated food allergy. Damage to the intestinal epithelial barrier upon exposure to food allergens allows allergen penetration and induces the release of alarmins. This activates antigen-presenting cells (APCs) and group 2 innate lymphoid cells (ILC2s), promoting naïve T cell differentiation into Th2 cells. Further, Th2 cytokines from ILC2s and Th2 cells induce IgE class switching in B cells. Allergen-specific IgE then binds to FcεRI receptors on mast cells, leading to mast cell sensitization. Upon re-exposure to the same allergens, sensitized mast cells can rapidly recognize the incoming allergens via IgE antibodies and initiate the degranulation process, releasing cytokines and chemokines that drive epithelial hyperplasia, inflammatory cell recruitment, and allergic inflammation. Abbreviations: Eos: eosinophils; Mono: monocytes; Neu: neutrophils; Treg: regulatory T cell; TSLP: thymic stromal lymphopoietin; GM-CSF: granulocyte–macrophage colony-stimulating factor; LTB4: leukotriene B4.

Figure 3

The classification and framework of allergenicity assessment methods. Allergenicity assessment methods can be classified into three categories: MS-based methods (e.g., MS identification, bioinformatic prediction, and simulated digestion), serology-based methods (e.g., ELISA and cell models), and animal-based methods (e.g., rodent and non-rodent models). MS-based methods detect allergen sequences to predict allergic epitopes. Serology-based methods rely on antigen–antibody reactions and depend heavily on the availability of allergen-specific sera. Animal-based models replicate sensitization routes to generate in vivo data reflecting allergenicity and sensitization mechanisms similar to those in humans. Each positive result indicates that the tested food allergen has the potential to induce an allergic reaction. Abbreviations: β-Hex; sIgE: allergen-specific IgE.