Gluten
For the food product made from gluten see Wheat gluten (food). |
Wheat - a prime source of gluten |
Gluten is an amorphous
ergastic protein found combined with
starch in the
endosperm of some
cereals, notably
wheat,
rye, and
barley. It constitutes about 80% of the proteins contained in wheat, and is composed of the proteins
gliadin and
glutenin. Gluten is responsible for the
elasticity of
kneaded dough, which allows it to be
leavened, as well as the "chewiness" of baked products like
bagels. It is the glutenins (specifically, high molecular weight glutenins) that are especially critical to gluten quality.
Gluten can be extracted from the
flour of wheat and other grains by washing out the
starch. To do this, a simple
dough of flour and water is rinsed with plain water and kneaded until the rinsing water remains clear and free from starch and
bran. For
chemical, non-food purposes, a
saline solution provides better results. The remaining lump of gluten should have a stringy, sticky texture reminiscent of
chewing gum.
Cooked gluten becomes firm to the bite and soaks up a certain amount of the surrounding
broth and its taste. It is therefore commonly used in
vegetarian cuisine, notably
Buddhist cuisine and
vegan cuisine, where one variety is called
seitan. Some consider it a convincing
imitation meat (particularly duck) when the broth is flavored accordingly.
In the process of
baking with
yeast, gluten is responsible for keeping the
fermentation gases in the dough, allowing it to rise. After baking, the
coagulated gluten ensures that the final product keeps its shape (although
starch is also essential for structural integrity). Recently, gluten has also been implicated as being at least partially responsible for bread staling.
Gluten is found in some cereals (e.g.,
wheat,
rye,
barley) and their end products. Wheat grown in countries with extreme weather conditions, such as
Canada tends to have a higher gluten content than wheat grown in countries where the winter is milder. Wheat
flour with a high gluten content is called "strong" flour, and is used for breads, whereas flour with a lower gluten content is called "soft" flour, and is used for cakes. No gluten is contained in
rice (even
glutinous rice),
wild rice,
maize (corn),
millets,
buckwheat,
quinoa, or
amaranth.
Oats and
teff do not contain gluten, but are sometimes grown directly adjacent to, and/or milled on the same equipment as, other grains that do contain gluten, and so are commonly contaminated. Non-cereals such as
soybeans and
sunflower seeds contain no gluten.
Other varieties of wheat such as
kamut and
spelt have slightly different forms of gluten. The gluten in spelt is more fragile than that found in wheat, and the bread dough can therefore collapse if overmixed. Many people who are unable to digest gluten for non-
celiac reasons are often able to digest these varieties. People suffering from
coeliac disease are advised to avoid all forms of gluten.
Celiac disease, in which the body has an auto-immune reaction upon consumption of gluten.
*
Gluten-free, casein-free diet*
Textured vegetable protein*
Wheat gluten (food)*
Zein*
gluten free beer*
Glutenfreebeerfestival.com
