**1. Introduction**

A food allergy occurs once the body develops a specific and repetitive immune response to certain foods [1]. It can be divided into two major categories based on the mechanism involved: (i) the immunoglobulin E (IgE)-mediated, such as allergy to proteins from milk, egg, peanut

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

etc. It is the most severe reaction, especially to food containing proteins, and (ii) the non-IgE-mediated allergy such as that of gluten or celiac disease, where the allergic symptom is triggered by ingestion of gluten from cereals namely wheat, rye and barley in their diets. In recent years, food allergies have caused a major health alarm affecting nearly 1% of adult population in the world and from 6 to 8% of children [2–4]. Thus, the prevalence of food allergies has increased in several regions all over the world. Further, more than 170 types of foods have been identified as potentially allergenic [5]. The animal-derived sources include eggs, milk, fish and crustacean shellfish; whereas the vegetable-derived sources include wheat, soy and nuts. The former group of proteins are responsible for causing more than 90% of allergic reactions [5, 6]. Most food allergens are stable molecules that resist the effect of food processing, cooking and the digestive process. These glycoproteins are characterized by their ability to induce a pathogenic IgE response in susceptible individuals [7]. Usually, food allergens are formed by divalent or multivalent molecules with two or more antibodies–binding sites calls epitopes, which are responsible for interacting with immune effector molecules such as the IgE antibodies [2–4]. Moreover, many food proteins especially those derived from animal sources could act as antigens in humans.

Currently, there is a worldwide search for new materials of natural origin that confers the physical, chemical and sensory characteristics to food products similar to those of synthetic additives applied on a daily basis. These synthetic compounds have been considered as potentially toxic in hypersensitive people, leading to health problems, causing allergies, hyperactivity, and cancer [8–11].

Proteins are macromolecules considered as emergents, these are versatile compounds having a good biocompatibility, biodegradability, high nutritional value, amphiphilic properties, and exhibit a strong interaction with several types of active compounds via hydrogen bonds, and electrostatic interactions [12]. Further, proteins are also able to function as emulsifiers, foaming and gelling agents [13–16]. Their chemical and structural versatility makes them suitable candidates for the delivery of bioactive hydrophobic and hydrophilic ingredients from a wide range of platforms such as particles, fibers, films and hydrogels [16].

One of the emerging and promising uses of proteins is in the microencapsulation tecnology of different compounds in the pharmaceutical, food and cosmetic fields. This technology is defined as a mechanical, chemical or physico-chemical process that isolates and protects the potentially sensitive active ingredients (i.e., liquid, solid or gas) from the damaging environment. In most cases, spherically-shaped products are obtained and the resulting particles could be classified according to their size as capsules (1–1000 μm), microcapsules (100–1000 nm) or nanocapsules (1–100 nm). In this process, the active ingredient is protected from the environment by a membrane, which in turn is named as the wall or coating material. This membrane controls the release and stability of the core material [17]. Nonetheless, to date, only a few proteins have been considered to be effective coating materials for the encapsulation of several core compounds such as vitamins, minerals, microorganisms, oils, phenolic compounds, among others. These proteins are mainly obtained from animal sources rather than plant sources. Proteins derived from milk, wheat, soy and cereals are the most widely studied for this aplication, but are considered as allergenic. For this reason, research has focused on the search for new sources of nonallergenic proteins that allows for the modification of their physical structures using chemical treatments such as the Maillard, hydrolysis, acylation or cationization reactions to improve the encapsulating capacity of the protein and in turn, decrease their allergenicity.
