Explain changes in gluten proteins during dough formation, Biology

Assignment Help:

Changes  In Gluten Proteins During Dough Formation

Initially, gluten is formed when flour and water are mixed together. The proteins in the flour, glutenin and gliadin cross  link, using water as a vehicle to form gluten. Enhancing this gluten structure  is important relative to developing a gas retaining structure in the chapati/bread.   When the hydrated bread flour is mixed and kneaded, the gluten proteins orient themselves aligns and partially unfolded. This enhances hydrophobic interaction and formation of disulphide bridges through -S-S- interchange reactions.  A  3-dimensional viscoelastic protein network is established, as the initial gluten particles transform into this membrane (film), thus serving to entrap starch  granules and other flour components.  Cleavage  of disulphide bridges by reducing agents such as cysteine,  destroys the cohesive structure of hydrated gluten and  bread dough ;  the addition of  agents  such  as  bromates,  increase  toughness    and elasticity. "Strong" flours from certain wheat varieties require long mixing time and give very cohesive dough. "Weak flours"  are less effective and  gluten network breaks down when the energy  or duration of mixing exceeds a certain level, probably because of -S-S-  bonds  are ruptured (especially in absence of  air). 

Dough strength  appears  to  be  related to a  large   content  of  high molecular   weight glutenins including totally insoluble  "residue proteins". From experiments with "reconstituted" wheat flours  of varying  gliadin and glutenin  ratios, it can be  postulated  that the  glutenins are responsible for the  elasticity,  cohesiveness and  mixing  tolerance  of  dough  whereas  gliadins   facilitate fluidity,   extensibility  and  expansion  of  the  dough, thus contributing  to a larger bread loaf volume. A proper balance of the proteins is essential for bread making.  Excessive  cohesion (glutenins)  inhibit \the expansion of trapped CO2 bubbles  during fermentation,  the rise of the dough and the subsequent  presence of  open  air cells in the bread  crumb.  Excessive extensibility (gliadins) results in gluten films that are weak and permeable; thus retention of CO2 is poor and dough collapse may occur.

 


Related Discussions:- Explain changes in gluten proteins during dough formation

Different mechanisms responsible for corneal avascularity, What are the dif...

What are the different mechanisms responsible for corneal avascularity? Various mechanisms responsible for its avascularity are as follows: a) Chemical Theory: I) Role o

Advances in mineral and vitamin nutrition of livestock, Advances in Mineral...

Advances in Mineral and Vitamin Nutrition of Livestock Even though, minerals and vitamins as nutrients are as essential as energy and protein, general negligence occurs primari

Why is it hard to produce vaccines against dengue and aids, Q. Why is it di...

Q. Why is it difficult to produce efficient vaccines against a viral infection like dengue and AIDS? It is difficult to make vaccines for dengue because there are four differen

Define tests of cardiovascular endurance, Define Tests of Cardiovascular E...

Define Tests of Cardiovascular Endurance? Cardiovascular endurance or aerobic fitness is the ability to exercise continuously for extended periods without tiring. It can be me

Explain about the food spoilage, Explain about the Food Spoilage? Foods...

Explain about the Food Spoilage? Foods gradually undergo deterioration or spoilage from the time they are harvested, caught, slaughtered or manufactured. Therefore, delay in th

Briefly explain what is the leaf, Briefly explain what is The Leaf? In a ...

Briefly explain what is The Leaf? In a typical dicot, leaf primordia arise from the apical meristem, which is housed within the terminal bud on a shoot. The leaf cells are produc

Enzymology, Ethylene glycol is a poison that causes about fifty deaths a ye...

Ethylene glycol is a poison that causes about fifty deaths a year in the United States. Treating people who have drunk ethylene glycol with massive doses of ethanol can save their

Define the effect of deficiency of vitamin k, Define the Effect of Deficien...

Define the Effect of Deficiency of Vitamin K? Both excess and low intakes can have serious implications on human health, although such conditions arise rarely, these can often

What is the incubation period of an infection, What is the incubation perio...

What is the incubation period of an infection? Incubation period is the time interval among the infection by an agent that causes disease and the first signs or symptoms of th

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd