Food allergens are considered to be able to exert systemic allergic reactions only after they have been absorbed through the intestinal mucosa (Astwood, Leach, & Fuchs, 1996). As a result, the resistance of the IgE binding capacity of an allergen towards digestion in the human gastro-intestinal tract is considered an important factor. Heat processing may affect the digestibility of a protein. Taking into account that most foods are being consumed after some kind of heat processing, the digestibility of pre-heated allergens is an important characteristic as well.