Effects of Food Processing on Allergenicity

There is an increasing awareness among clinicians that industrial and household food processing methods can increase or decrease the allergenicity of foods. Modification to allergen properties through processing can enable dietary liberations. Reduced allergenicity may also allow for lower risk immunotherapy approaches. This review will equip physicians, nurses, dieticians and other health care providers with an updated overview of the most clinically oriented research in this field. We summarize studies assessing the allergenicity of processed foods through clinically accessible means, such as oral food challenges, skin prick tests, and sIgE levels.

Baking, boiling, canning, fermenting, pasteurizing, peeling, powdering, and roasting heterogenously impact the likelihood of reactivity in egg-, milk-, peanut- and other legume-, tree nut-, fruit-, and seafood-allergic patients. These variations may be due to the use of different temperatures, duration of processing, presence of a matrix, and the specific allergens involved, among other factors. Accurate prediction of tolerance to processed allergens with skin prick tests and sIgE levels remains largely elusive. Food allergy management strategies, especially with milk and egg, have capitalized on the decreased allergenicity of baking. Many milk- and egg-allergic patients tolerate baked and heated forms of these allergens, and the use of these processed foods in oral immunotherapy (OIT) continues to be extensively investigated. Heat is also well recognized to reduce allergic symptoms from some fruits and vegetables in food-pollen syndrome. Other forms of processing such as boiling, fermenting, and canning can reduce allergenicity to a diverse array of foods. Roasting, on the other hand, may increase allergenicity. The application of food processing to food allergy treatments remains largely unexplored by large clinical studies and provides a key avenue for future research. The recognition that food allergy represents a spectrum of hypersensitivity, rather than an all-or-nothing phenomenon, has led to approaches to enable dietary liberation with processed, less-allergenic foods and their use in food allergy immunotherapies.