Food allergens, and their modifications by food technology

Food allergens are certain proteins, defined by their molecular weight, their isoelectric point, and their capacity to bind to specific IgE. Binding site are conformational or sequential epitopes. Isoallergens are defined by their structural homology, greater than 67%. Variants are characterized by minimal differences of amino acids. Identification of the amino acid sequence of an allergen allows its synthesis by genetic engineering, and inclusion in the nomenclature of allergens. Vegetable allergens can be classified into several groups: profilins, PR proteins, enzymes, storage proteins, stress proteins, ubiquitous allergens represented by carbohydrate residues. The conditions of allergenicity of certain food proteins depend on the resistance to heat denaturation and gastrointestinal enzymes, preferential access to the gastrointestinal mucosa (due to a high intake or by more effective endocytosis), the existence of crossed reactions with inevitable exposure allergens (pollens). Food industry technologies introduce certain changes: the use of dietary proteins as additives, prolonged storage, heating creating neoallergens, risks of transgenic foods, introduction of new dietary proteins onto the market.