Engineering Food Allergenicity: Mechanisms and Applications of Thermal and Non-Thermal Processing Technologies

Food allergies represent a growing global public health challenge arising from complex interactions among genetic predisposition, environmental exposures, dietary habits, and gut microbiota. Sensitization may occur through dermal, respiratory, or gastrointestinal routes and is strongly influenced by epithelial barrier dysfunction and Th2-skewed immune responses. A detailed understanding of allergen structure, immune recognition, and sensitization pathways is therefore essential for the development of effective mitigation strategies. Both thermal and non-thermal food processing technologies have been investigated for their ability to reduce the allergenicity of common foods, including milk, egg, peanut, tree nuts, and seafood. Conventional thermal processing can denature allergenic proteins and enhance digestibility, but may also adversely affect nutritional value and sensory quality. In contrast, emerging non-thermal technologies—such as High Hydrostatic Pressure (HHP), Pulsed Ultraviolet (PUV) light, cold plasma, ultrasound, pulsed electric fields, and gamma irradiation—offer alternative approaches that induce targeted structural modifications in allergenic proteins while better preserving product quality. However, the effectiveness of these technologies is highly context-dependent, varying with the food matrix, processing parameters, and allergen type; moreover, reductions in Immunoglobulin E (IgE) reactivity observed in vitro do not always translate into clinically meaningful outcomes. Limitations in standardized allergenicity assessment, insufficient in vivo and clinical validation, and challenges related to scalability and regulatory acceptance remain significant barriers. This review integrates immunological mechanisms with food engineering perspectives to critically evaluate thermal and non-thermal processing strategies, highlighting the translational potential of non-thermal technologies as promising, scalable tools for developing safe, quality-preserving, and clinically relevant hypoallergenic foods.