Allergenicity and food processing

Authors: McHugh, Tara; Maleki, Soheila

Submitted to: Food Technology
Publication Type: Popular Publication
Publication Acceptance Date: 9/24/2020
Publication Date: 10/10/2020
Citation: McHugh, T., Maleki, S.J. 2020. Allergenicity and food processing. Food Technology. 1020:77-79.

Interpretive Summary: Food allergy is complicated. It is defined as ‘‘an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food’’. Allergies are immunologically mediated reactions that affect various organs such as the skin, gut, and airways. The prevalence of allergic conditions have continued to increase at an alarming rate. In fact, a U.S. survey repeated on 3 occasions presented the opportunity to compare the prevalence of peanut allergy in children from 1997 to 2008 showing that the rate more than tripled from 0.4% to 1.4% 1. Food allergy is currently reported to affect nearly 5% of adults and 8% of children 2. Potentially any food can cause food allergy, but there are 8 foods (milk, egg, soy, wheat, fish, shellfish, peanuts, and tree nuts) that most commonly cause food allergies in the U.S. and are required to be labeled by the Food Allergen Labeling and Consumer Protection Act (FALCPA) of 2004. Immunoglobulin E (IgE, which is the primary mediator of food allergic reactions)-mediated food allergies are classified as Type I or immediate hypersensitivity. It is known that IgE-mediated mast cell degranulation, which results in the release of chemical mediators, such as histamine, is a strategy that evolved to eliminate respiratory or gastrointestinal pathogens. However, few reasons have been offered to explain why certain foods elicit immunological responses similar to those elicited by multicellular metazoan parasites that reside in the respiratory and gastrointestinal systems, while other foods are tolerated and nonallergic. Whereas many of the structural characteristics, homology and cross reactivity of food allergens have been explained, specific immunological and biophysical properties of the allergens that contribute to IgE antibody formation are not fully understood. Some of the immunological properties of allergenic proteins include their ability to stimulate Th-2 type T-cell proliferation, bind serum IgE, elicit a positive prick skin test, and cause histamine and mediator release from mast cells and basophils of sensitive individuals. Characteristic biochemical properties of allergens are that they are proteins or glycoproteins with molecular weights between about 5-100 kDa, which are usually abundant in the food source and often stable to digestion by gastrointestinal enzymes. Specific structural features and functional similarities, such as protease activity, have also been associated with both food and inhaled allergens (i.e. pollen, cat, dog, dust mite, etc).

Technical Abstract: Food allergy is complicated. It is defined as ‘‘an adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food’’. Allergies are immunologically mediated reactions that affect various organs such as the skin, gut, and airways. The prevalence of allergic conditions have continued to increase at an alarming rate. In fact, a U.S. survey repeated on 3 occasions presented the opportunity to compare the prevalence of peanut allergy in children from 1997 to 2008 showing that the rate more than tripled from 0.4% to 1.4% 1. Food allergy is currently reported to affect nearly 5% of adults and 8% of children 2. Potentially any food can cause food allergy, but there are 8 foods (milk, egg, soy, wheat, fish, shellfish, peanuts, and tree nuts) that most commonly cause food allergies in the U.S. and are required to be labeled by the Food Allergen Labeling and Consumer Protection Act (FALCPA) of 2004. Immunoglobulin E (IgE, which is the primary mediator of food allergic reactions)-mediated food allergies are classified as Type I or immediate hypersensitivity. It is known that IgE-mediated mast cell degranulation, which results in the release of chemical mediators, such as histamine, is a strategy that evolved to eliminate respiratory or gastrointestinal pathogens. However, few reasons have been offered to explain why certain foods elicit immunological responses similar to those elicited by multicellular metazoan parasites that reside in the respiratory and gastrointestinal systems, while other foods are tolerated and nonallergic. Whereas many of the structural characteristics, homology and cross reactivity of food allergens have been explained, specific immunological and biophysical properties of the allergens that contribute to IgE antibody formation are not fully understood. Some of the immunological properties of allergenic proteins include their ability to stimulate Th-2 type T-cell proliferation, bind serum IgE, elicit a positive prick skin test, and cause histamine and mediator release from mast cells and basophils of sensitive individuals. Characteristic biochemical properties of allergens are that they are proteins or glycoproteins with molecular weights between about 5-100 kDa, which are usually abundant in the food source and often stable to digestion by gastrointestinal enzymes. Specific structural features and functional similarities, such as protease activity, have also been associated with both food and inhaled allergens (i.e. pollen, cat, dog, dust mite, etc).