1. How does Gluten work?
Gluten Components
Gluten is a large protein that is found in cereals. It is responsible for the
elasticity and extensibility of bread and other cereal products. The two main
components of gluten are glutenin and gliadin.
Glutenin:
The glutenin component of gluten is responsible for the
elasticity of the dough. Being elastic allows the dough to
hold the shape it is being formed in. Glutenin is
polymeric meaning that is made up of lots of amino
acids that link together to form a large string-like
structure.
Glutenin is high in a specific amino acid called cystine. Cystine
allows for disulfide bonding which cross-links the chains of amino
acids, giving the gluten its elastic properties. You can see disulfide
bonding in the picture to the left. Cystine has a SH tail which
allows it to bond with other SH tales. The two hydrogen atoms are
released, resulting in a flexible disulfide bond.
Gliadin:
The gliadin component of gluten is responsible for the
extensibility and stickiness of the dough. Being extensible
allows the dough to be stretched and allows air to be
kneaded into the product. The stickiness property holds
the dough together. Gliadins are monomeric proteins,
meaning they are not interlinked, so they are often
represented as small circles compared to glutenin’s string-like structure.
Gluten:
The two parts of gluten, glutenin and gliadin, give
gluten its physical properties. They are found in
equal quantities in gluten. This allows for the
dough to be elastic and extensible, resulting in the
products overall qualities.
Visual Sources:
https://grist.org/food/2011-11-10-gluten-why-all-the-fuss/
http://en.citizendium.org/wiki/Cystine