In general, allergenic foods are resistant to processes commonly used in food manufacturing. Nearly all the causative proteins (allergens) retain their allergenicity after treatment by heat and/or proteolysis. Notable exceptions exist; for example, the allergenicity of many fresh fruits and vegetables is decreased or removed by relatively mild processes such as gentle heating or mashing. The use of proteolytic enzymes to remove allergenicity is successfully used in the production of hypoallergenic infant formulas, but this approach with other allergenic foods has resulted in only limited success. Processing effects can result in decreased or complete removal of allergenic qualities of a food, such as the removal of proteins in oilseed processing, which renders the oils hypoallergenic and safe for consumption by allergic individuals. This discussion will address the different allergenic foods and processes which can affect or decrease their allergenicity.