Explain starch gelatinization, Biology

Assignment Help:

Starch gelatinization

Undamaged starch granules are insoluble in cold water but can imbibe water  reversibly i.e. they can swell slightly and then return to their original size on drying, when starch is heated with excess of water, the molecular order of the granule is gradually and irreversibly destroyed at the gelatinisation temperature, which is approximately in the  range of 60-70°C for most of the starches. Amylose is preferentially leached out of the network and gets solubilized, however, some leaching of amylose can also occur prior to gelatinization. When further heated, starch granules are disrupted and partial solubilization is achieved. Total gelatinization usually occurs over a temperature range with larger granules generally gelatinizing first. At temperatures below 100° C, true molecular solution is not achieved and the swollen hydrated granules consisting of mainly amylopectin remain.  Continued heating of starch granules in excess water results in further granule swelling, additional leaching of soluble components (primarily amylose) and eventually, total disruption of granules especially with the application of shear forces,. This phenomenon results in the formation of a starch paste. The melting temperature of the crystallites is 190°C. Gelatinization is an endothermic process (10 mJ/mg), i.e. a chemical reaction accompanied by the absorption of heat.   

 


Related Discussions:- Explain starch gelatinization

Define the glucose tolerance test, Q. Define the Glucose Tolerance Test? ...

Q. Define the Glucose Tolerance Test? In Glucose Tolerance Test (GTT) if the blood sample is to be taken in the morning, patient is advised to follow fasting instructions i.e.

How plants control opening and closing of the stomata, How plants control t...

How plants control the opening and the closing of the stomata? The closing and the opening of the stomata depend upon the necessity of the plant to lose water and heat through

How is the cerebrum anatomically divided, How is the cerebrum anatomically ...

How is the cerebrum anatomically divided? The cerebrum is divided into two cerebral hemispheres, the right and the left. Each hemisphere is made of four cerebral lobes: frontal

Clinical criteria for diagnosis of infective endocarditis, Major Criteria ...

Major Criteria 1) Positive blood culture • Typical microorganism for infective endocarditis from two separate blood cultures Viridans streptococci, Streptococcus bovis, HAC

Define briefly about the cereal proteins, Define briefly about the Cereal P...

Define briefly about the Cereal Proteins? Cereal grains, properly ripened and dried for optimum storage stability, have protein content ranging from 6-20%. Proteins are found i

Haccp - what is validation, HACCP - What is Validation Validation   : ...

HACCP - What is Validation Validation   :  That element of verification focused on collecting and evaluating scientific and technical information to determine  if  the HACCP

What are the main respective constituents of cell walls in, What are the ma...

What are the main respective constituents of cell walls in bacteria, protists, fungi and plants? In bacteria the cell wall is made of peptidoglycans; between protists algae hav

Nutritional management of food allergies & food intolerance, Define Nutriti...

Define Nutritional Management of Food Allergies and Food intolerance? In this unit we will be discussing the adverse reactions associated with food. You may have read or heard

Define about yersiniosis, Define about Yersiniosis In the genus Yersini...

Define about Yersiniosis In the genus Yersinia, 11 species are recognized, including Y. pestis, the cause of plague. The species of primary interest in foods is Y. enterolytica

Illustrate the removal of carbon dioxide from the body, Which of the follow...

Which of the following processes in capillaries in the lung assist in the removal of carbon dioxide from the body? A. Net flux of carbon dioxide from red blood cells into plasm

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