**1. Introduction**

Approximately 8% of children and 1–2% of adults suffer from food allergy worldwide, and the perceived prevalence is even much higher, up to 22% of the population, constituting a fast growing health problem [1, 2]. The prevalence of food allergies is continuously increas‐ ing in the last decades, especially in the developed countries. The Big‐8 of food allergens, namely the foods that are mainly involved in these immunological reactions, are milk, eggs,

© 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.

fish, crustaceans, peanuts, tree nuts, soybeans and wheat. These foodstuffs can be eaten by most of the population without problems, but they can give a strong immunological reaction with topic and systemic consequences in sensitive people [3, 4]. Thus, the only therapy avail‐ able for patients suffering from food allergy is the strict avoidance of the offending food. This means that allergic consumers must absolutely avoid eating foods that could provoke potentially life‐threatening reactions. Successful avoidance depends on having complete and accurate information on food labels. Thus, huge efforts are made by regulatory agen‐ cies, with the collaboration of food industry, to protect allergic consumers, to ensure that all food allergens present in the food are declared on the label and that effective controls are used to prevent the presence of unintended allergens [5]. In the case of children, dietary elimination of nutrient‐dense foods may result in inadequate nutrient intake and impaired growth: children with multiple food allergies have a higher risk of impaired growth and may have a higher risk of inadequate nutrient intake than children without food allergies. In addition to this, the social lifestyle of individuals with food allergy and of their families can be severely disadvantaged, since they need to constantly avoid the allergenic ingredi‐ ent [6]. This task becomes more difficult to manage when people do not eat at home but in restaurants, canteens and other food chains, even if a list of the ingredients of all the dishes must be provided. Moreover, the repercussions of food allergy are not only limited to individuals or households: the food industry must also sustain a lot of extra costs due to food allergy. Primarily, legislative changes, such as the new EU‐legislation on food labelling (EU Directive 2003/89/EC amending Directive 2000/13/EC), force the industry to adapt pro‐ ductive processes, food labelling and monitoring to improve allergic consumer protection. The burden of responsibility falls to the food manufacturer, who is required to manage pro‐ duction processes to ensure allergenic ingredients are labelled [7]. Up to now, the potential social impact and economic costs of food allergy on the individual, families, health‐related services and food industry are relevant.

Wheat is in the list of the eight main allergenic foods, because the gluten contained in it is the main external trigger of celiac disease. Celiac patients eat several types of gluten‐free prod‐ ucts, some of them are naturally gluten‐free foods (fruits, vegetables and unprocessed meat, fish and poultry) but some others are gluten‐free substitute foods (pasta, bread, cereals, crack‐ ers and snack foods) where wheat flour is replaced by gluten‐free flours. Gluten‐free products can be purchased at general and specialty food stores as well as via Internet. Several stud‐ ies demonstrated that gluten‐free food is not always readily available, and it is considerably more expensive than regular, gluten‐containing foods [8]. The increasing incidence of celiac disease in the population has negative effects not only on the quality of life but also on the health care system: it has been estimated that the average annual health care costs per‐patient in primary care significantly increased by 91% for CD patients after they had been diagnosed with the disease [9]. The impact is also evident for the agricultural and food sectors: wheat is one of the first three cereals for diffusion and cultivation for human nutrition. Gluten, the main trigger of celiac disease, is at the basis of rheological properties of wheat‐based prod‐ ucts. In fact, the formation of a gluten network in the dough is of outmost importance for air bubbles and starch retention (respectively for leavened products and pasta). A low gluten content of the flour leads to loss of product shape in the case of leavened products and to soft and mushy pasta. The consequence is that wheat breeding has been, during the last decades, oriented toward increasing yield and the amounts of amylopectin, gluten and protein [10].

fish, crustaceans, peanuts, tree nuts, soybeans and wheat. These foodstuffs can be eaten by most of the population without problems, but they can give a strong immunological reaction with topic and systemic consequences in sensitive people [3, 4]. Thus, the only therapy avail‐ able for patients suffering from food allergy is the strict avoidance of the offending food. This means that allergic consumers must absolutely avoid eating foods that could provoke potentially life‐threatening reactions. Successful avoidance depends on having complete and accurate information on food labels. Thus, huge efforts are made by regulatory agen‐ cies, with the collaboration of food industry, to protect allergic consumers, to ensure that all food allergens present in the food are declared on the label and that effective controls are used to prevent the presence of unintended allergens [5]. In the case of children, dietary elimination of nutrient‐dense foods may result in inadequate nutrient intake and impaired growth: children with multiple food allergies have a higher risk of impaired growth and may have a higher risk of inadequate nutrient intake than children without food allergies. In addition to this, the social lifestyle of individuals with food allergy and of their families can be severely disadvantaged, since they need to constantly avoid the allergenic ingredi‐ ent [6]. This task becomes more difficult to manage when people do not eat at home but in restaurants, canteens and other food chains, even if a list of the ingredients of all the dishes must be provided. Moreover, the repercussions of food allergy are not only limited to individuals or households: the food industry must also sustain a lot of extra costs due to food allergy. Primarily, legislative changes, such as the new EU‐legislation on food labelling (EU Directive 2003/89/EC amending Directive 2000/13/EC), force the industry to adapt pro‐ ductive processes, food labelling and monitoring to improve allergic consumer protection. The burden of responsibility falls to the food manufacturer, who is required to manage pro‐ duction processes to ensure allergenic ingredients are labelled [7]. Up to now, the potential social impact and economic costs of food allergy on the individual, families, health‐related

Wheat is in the list of the eight main allergenic foods, because the gluten contained in it is the main external trigger of celiac disease. Celiac patients eat several types of gluten‐free prod‐ ucts, some of them are naturally gluten‐free foods (fruits, vegetables and unprocessed meat, fish and poultry) but some others are gluten‐free substitute foods (pasta, bread, cereals, crack‐ ers and snack foods) where wheat flour is replaced by gluten‐free flours. Gluten‐free products can be purchased at general and specialty food stores as well as via Internet. Several stud‐ ies demonstrated that gluten‐free food is not always readily available, and it is considerably more expensive than regular, gluten‐containing foods [8]. The increasing incidence of celiac disease in the population has negative effects not only on the quality of life but also on the health care system: it has been estimated that the average annual health care costs per‐patient in primary care significantly increased by 91% for CD patients after they had been diagnosed with the disease [9]. The impact is also evident for the agricultural and food sectors: wheat is one of the first three cereals for diffusion and cultivation for human nutrition. Gluten, the main trigger of celiac disease, is at the basis of rheological properties of wheat‐based prod‐ ucts. In fact, the formation of a gluten network in the dough is of outmost importance for air bubbles and starch retention (respectively for leavened products and pasta). A low gluten content of the flour leads to loss of product shape in the case of leavened products and to soft

services and food industry are relevant.

312 Wheat Improvement, Management and Utilization

At the moment, no therapies are available for people that are already celiac, so the only treat‐ ment is the gluten‐free diet. But, on the other hand, efforts can be made in the direction of decreasing celiac disease incidence. Different hypotheses have been made on the reasons of the increased incidence of celiac disease. Since celiac disease affects the gastrointestinal tract, the gut microflora can play a key role in the loss of the immunological tolerance. For example, rod‐shaped bacteria in the upper small bowel are present in one‐third of the children with CD but in less than 2% of the controls [11]; another study showed that the species *Bacteroides fragilis* is more abundant in the intestinal microbiota of CD patients, whereas *Bacteroides ovatus* is less abundant in comparison to healthy controls [12]. Besides usual microflora, also viral and bacterial gastroenteritis may have a role in celiac disease pathogenesis; in fact, it has been previously demonstrated that a high frequency of rotavirus infections may increase the risk of celiac disease autoimmunity in childhood in genetically predisposed individuals [13]. For what concerns gluten, timing of gluten introduction into the infant diet is associ‐ ated with risk of celiac disease autoimmunity [14]. Recent studies demonstrated that the oral tolerance to gluten can be lost also in the elderly [15]; the study was conducted after a cohort from 1974 up to now. In parallel, it appears that vital gluten consumption has tripled since 1977. This increase is of interest because it is in the time frame that fits with the predictions of an increase in celiac disease [16]. It seems that massive and early exposure to gluten can be one of the causes of the switch from oral tolerance to celiac disease. Another cause that it has been hypothesized is the transition from sourdough fermentation of bread and baked prod‐ ucts to yeast fermentation. So, the bacterial proteolytic activity is rather promising not only as currently demonstrated for eliminating traces of contaminant gluten but probably also in perspective for the manufacture of tolerated baked goods [17].

Thus, trying to decrease these risk factors could help to stop the rising of celiac disease inci‐ dence. It is known for a long time that breast feeding has a protective effect against the devel‐ opment of celiac disease, especially when it is still ongoing during gluten introduction in the diet. Also the improvement of infant milk formula, decreasing protein content and osmolar‐ ity, has helped to reduce celiac disease incidence [18]. Obviously, the easiest way to reduce the amount of gluten ingestion is the reduction of wheat‐derived products consumption, but this would mean a kind of "preventive gluten‐free diet", with all the problems and limitations previously described (first of all the decrease in life quality). An alternative way could be the reduction of gluten content in wheat (in contrast with what has been done in the last decades), but this would mean a dramatic decrease in the texture quality of baked products and pasta. Since gluten proteins have a reserve role (nitrogen stock), they underwent to a limited evo‐ lutionary pressure, thus showing a high‐sequence variability with a lot of different isoforms. This lays the groundwork for a possible varietal selection aimed to have the same total glu‐ ten amount (maintaining the same rheological properties) but expressing protein isoforms with a reduced content of sequences involved in celiac disease. In this way, the exposure of the population to immunotoxic sequences will be reduced and, possibly, also the incidence of the disease.
