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

Amylase stock solution, Assume that you have 1 mL of a solution amylase (an...

Assume that you have 1 mL of a solution amylase (an enzyme) at a concentration of 15 mg protein/mL. Calculate the volume of diluting buffer that you would have to add to 1.0 mL of

Can you illustrate chylomicrons, Q. What is the special route that lipids f...

Q. What is the special route that lipids follow during digestion? What are chylomicrons? Triglycerides emulsified by the bile within micelles suffer the action of lipases that

Explain the dimensions of practice of nutrition care process, The nutrition...

The nutrition care process acknowledges the common dimensions of practice by  the following: Defining a common language that allows nutrition practice to be more measurable,

Major events during gastrulation, MAJOR EVENTS DURING GASTRULATION - 1....

MAJOR EVENTS DURING GASTRULATION - 1.       There is rearrangement of cells due to morphogenetic movement of the cells of blastoderm. 2.       The three primary germ layer g

Define biosynthesis and secretion of thyroid hormones, Define Biosynthesis ...

Define Biosynthesis and Secretion of Thyroid Hormones? Histologically, the functional cells of the thyroid gland are arranged in follicles, which surround a central lumen conta

Sex-limited traits, Sex-Limited Traits Sex Limited Traits are traits ex...

Sex-Limited Traits Sex Limited Traits are traits expressed only in one sex, although the genes controlling thcm arc prcscnt as wcll as transmitted to both thc sexes. Therefore,

Determine the long buccal nerve, Long buccal nerve The long buccal nerv...

Long buccal nerve The long buccal nerve is a branch of the mandibular division of the trigeminal nerve which provides sensory innervation to the buccal gingiva and mucosa of th

Describe the working of immune system, Q. What is the function of the immun...

Q. What is the function of the immune system? The immune system performs specific defense against agents the antigens that are harmful to the body or foreign. Exogenous anti

Zoonotic diseases, Zoonotic Diseases The term zoonosis (zoonoses, plura...

Zoonotic Diseases The term zoonosis (zoonoses, plural) was coined by Rudolf Virchow to describe the disease transmitted from animal to man and vice versa. Zoonoses have been de

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