IGHE and food allergy: Nevertheless, although components of the food matrix can influence the digestibility and allergenicity of food proteins (107, 109), they apparently do not cause a delay in the onset of allergic reactions: in most food allergies, symptoms appear within minutes up to 2 h after food intake and this is in accordance with the time it takes for allergenic peptides to reach the IgE antibodies present on mast cells and basophils.