Related Research Articles
Gluten is a group of seed storage proteins found in certain cereal grains. Although, strictly speaking, "gluten" pertains only to wheat proteins, in the medical literature this term is used to refer to the combination of prolamin and glutelin proteins naturally occurring in all grains that have been demonstrated capable of triggering celiac disease. These include any species of wheat, barley, rye and oats, as well as any cross hybrids of these grains. Gluten comprises 75–85% of the total protein in bread wheat.
Wheat is a grass widely cultivated for its seed, a cereal grain which is a worldwide staple food. The many species of wheat together make up the genus Triticum; the most widely grown is common wheat. The archaeological record suggests that wheat was first cultivated in the regions of the Fertile Crescent around 9600 BCE. Botanically, the wheat kernel is a type of fruit called a caryopsis.
The oat, sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name. While oats are suitable for human consumption as oatmeal and oat milk, one of the most common uses is as livestock feed. Oats are associated with lower blood cholesterol when consumed regularly.
Coeliac disease or celiac disease is a long-term autoimmune disorder that primarily affects the small intestine. Classic symptoms include gastrointestinal problems such as chronic diarrhoea, abdominal distention, malabsorption, loss of appetite, and among children failure to grow normally. This often begins between six months and two years of age. Non-classic symptoms are more common, especially in people older than two years. There may be mild or absent gastrointestinal symptoms, a wide number of symptoms involving any part of the body or no obvious symptoms. Coeliac disease was first described in childhood; however, it may develop at any age. It is associated with other autoimmune diseases, such as Type 1 diabetes mellitus and Hashimoto's thyroiditis, among others.
Buckwheat, or common buckwheat, is a plant cultivated for its grain-like seeds and as a cover crop. The name "buckwheat" is used for several other species, such as Fagopyrum tataricum, a domesticated food plant raised in Asia. Despite the name, buckwheat is not related to wheat, as it is not a grass. Instead, buckwheat is related to sorrel, knotweed, and rhubarb. Buckwheat is referred to as a pseudocereal because its seeds' culinary use is the same as cereals', owing to their composition of complex carbohydrates.
A gluten-free diet (GFD) is a nutritional plan that strictly excludes gluten, which is a mixture of proteins found in wheat, as well as barley, rye, and oats. The inclusion of oats in a gluten-free diet remains controversial, and may depend on the oat cultivar and the frequent cross-contamination with other gluten-containing cereals.
Khorasan wheat or Oriental wheat, commercially known as kamut, is a tetraploid wheat species. It is an ancient grain type; Khorasan refers to a historical region in modern-day Afghanistan and Iran in northeast and parts of Central Asia. This grain is twice the size of modern-day wheat and is known for its rich, nutty flavor.
Gliadin is a class of proteins present in wheat and several other cereals within the grass genus Triticum. Gliadins, which are a component of gluten, are essential for giving bread the ability to rise properly during baking. Gliadins and glutenins are the two main components of the gluten fraction of the wheat seed. This gluten is found in products such as wheat flour. Gluten is split about evenly between the gliadins and glutenins, although there are variations found in different sources.
A whole grain is a grain of any cereal and pseudocereal that contains the endosperm, germ, and bran, in contrast to refined grains, which retain only the endosperm.
Wheat allergy is an allergy to wheat which typically presents itself as a food allergy, but can also be a contact allergy resulting from occupational exposure. Like all allergies, wheat allergy involves immunoglobulin E and mast cell response. Typically the allergy is limited to the seed storage proteins of wheat. Some reactions are restricted to wheat proteins, while others can react across many varieties of seeds and other plant tissues. Wheat allergy is rare. Prevalence in adults was found to be 0.21% in a 2012 study in Japan.
Triticeae is a botanical tribe within the subfamily Pooideae of grasses that includes genera with many domesticated species. Major crop genera found in this tribe include wheat, barley, and rye; crops in other genera include some for human consumption, and others used for animal feed or rangeland protection. Among the world's cultivated species, this tribe has some of the most complex genetic histories. An example is bread wheat, which contains the genomes of three species with only one being a wheat Triticum species. Seed storage proteins in the Triticeae are implicated in various food allergies and intolerances.
Gluten is the seed storage protein in mature wheat seeds. It is the sticky substance in bread wheat which allows dough to rise and retain its shape during baking. The same, or very similar, proteins are also found in related grasses within the tribe Triticeae. Seed glutens of some non-Triticeae plants have similar properties, but none can perform on a par with those of the Triticeae taxa, particularly the Triticum species. What distinguishes bread wheat from these other grass seeds is the quantity of these proteins and the level of subcomponents, with bread wheat having the highest protein content and a complex mixture of proteins derived from three grass species.
Gluten-related disorders is the term for the diseases triggered by gluten, including celiac disease (CD), non-celiac gluten sensitivity (NCGS), gluten ataxia, dermatitis herpetiformis (DH) and wheat allergy. The umbrella category has also been referred to as gluten intolerance, though a multi-disciplinary physician-led study, based in part on the 2011 International Coeliac Disease Symposium, concluded that the use of this term should be avoided due to a lack of specificity.
Anti-gliadin antibodies are produced in response to gliadin, a prolamin found in wheat. In bread wheat it is encoded by three different alleles, AA, BB, and DD. These alleles can produce slightly different gliadins, which can cause the body to produce different antibodies. Some of these antibodies can detect proteins in specific grass taxa such as Triticeae, while others react sporadically with certain species in those taxa, or over many taxonomically defined grass tribes.
Glutelins are a class of prolamin proteins found in the endosperm of certain seeds of the grass family. They constitute a major component of the protein composite collectively referred to as gluten. Glutenin is the most common glutelin, as it is found in wheat and is responsible for some of the refined baking properties in bread wheat. The glutelins of barley and rye have also been identified. Glutelins are the primary form of energy storage in the endosperm of rice grains.
Oat sensitivity represents a sensitivity to the proteins found in oats, Avena sativa. Sensitivity to oats can manifest as a result of allergy to oat seed storage proteins either inhaled or ingested. A more complex condition affects individuals who have gluten-sensitive enteropathy in which there is an autoimmune response to avenin, the glutinous protein in oats similar to the gluten within wheat. Sensitivity to oat foods can also result from their frequent contamination by wheat, barley, or rye particles.
The immunochemistry of Triticeae glutens is important in several inflammatory diseases. It can be subdivided into innate responses, class II mediated presentation, class I mediated stimulation of killer cells, and antibody recognition. The responses to gluten proteins and polypeptide regions differs according to the type of gluten sensitivity. The response is also dependent on the genetic makeup of the human leukocyte antigen genes. In gluten sensitive enteropathy, there are 4 types of recognition, innate immunity, HLA-DQ, and antibody recognition of gliadin and transglutaminase. With idiopathic gluten sensitivity only antibody recognition to gliadin has been resolved. In wheat allergy, the response pathways are mediated through IgE against other wheat proteins and other forms of gliadin.
Storage proteins serve as biological reserves of metal ions and amino acids, used by organisms. They are found in plant seeds, egg whites, and milk.
The cupin superfamily is a diverse superfamily of proteins named after its conserved barrel domain. The superfamily includes a wide variety of enzymes as well as non-enzymatic seed storage proteins.
Non-celiac gluten sensitivity (NCGS) or gluten sensitivity is defined as "a clinical entity induced by the ingestion of gluten leading to intestinal and/or extraintestinal symptoms that improve once the gluten-containing foodstuff is removed from the diet, and celiac disease and wheat allergy have been excluded".
References
- ↑ Shewry PR, Halford NG. Cereal seed storage proteins: structures, propertin utilization. J Exp Bot 2002;53:947-58. PMID__ 11912237.
- ↑ Holding, DR (2014). "Recent advances in the study of prolamin storage protein organization and function". Frontiers in Plant Science. 5: 276. doi: 10.3389/fpls.2014.00276 . PMC 4064455 . PMID 24999346.
- ↑ Bromilow, S; Gethings, LA; Buckley, M; Bromley, M; Shewry, PR; Langridge, JI; Clare Mills, EN (23 June 2017). "A curated gluten protein sequence database to support development of proteomics methods for determination of gluten in gluten-free foods". Journal of Proteomics. 163: 67–75. doi: 10.1016/j.jprot.2017.03.026 . PMC 5479479 . PMID 28385663.
