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

How can the abundance and diversity of living beings, How can the abundance...

How can the abundance and diversity of living beings in the tropical forests be explained? The biodiversity of these ecosystems can be defined by the great availability of the

What is osmotic pressure, Q. What is Osmotic Pressure? Ans. Import...

Q. What is Osmotic Pressure? Ans. Important characteristic of a cell is 'osmosis'. You would recall reading about osmosis in the Applied Physiology Course in Unit 8. I

Define quest of nutrition required for excercise, Define quest of nutrition...

Define quest of nutrition as sports nutrition as a discipline? Although the quest of nutrition as applied to exercise and sports dates back to ancient civilizations and importa

Design a controlled experiment, Design a controlled experiment to test the ...

Design a controlled experiment to test the hypothesis that acid precipitate inhibits the growth of elodea, a common freshwater plant.

Importance of the glucose blood level for human health, Q. What is the impo...

Q. What is the importance of the glucose blood level for human health? The glucose blood level (glycemia) must be kept normal if it is abnormally low there is not sufficient gl

Describe what types of results describe hypothesis, Why did giraffes develo...

Why did giraffes develop long necks? 1) Describe an experiment to test this hypothesis. Be explicit about the methods you will use, the setting, the time that the experiment wil

Explain risk evaluation, Explain Risk  evaluation Risk  evaluation: Th...

Explain Risk  evaluation Risk  evaluation: The  risk  evaluation involves: A) identification of a food safety problem B) Establishment of a risk profile C) Ranking of

Mammals - regeneration in vertebrates, Mammals - Regeneration in Vertebrate...

Mammals - Regeneration in Vertebrates Mammals are not capable of regenerating limb or tails. However, there are a few exceptions where lost tissues are regenerated. The annual

Calculation of maximum crop yield percent, Calculation of Maximum Crop Yiel...

Calculation of Maximum Crop Yield Percent It was pointed out previously that 1 Baule of any growth factor is equal in effect on growth to the effect of 1 Baule of any other fa

Illustrate about sarcoplasmic reticulum membranes, An increase in the calci...

An increase in the calcium conductance of all sarcoplasmic reticulum membranes of a skeletal muscle with no external forces on it leads to A. Increased binding of calcium ions

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