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

What are the factors affecting taste quality, Q. What are the factors Affec...

Q. What are the factors Affecting Taste Quality? You may have experienced that the four primary tastes i.e., sweet, sour, salty and bitter are not sensed with an equal ease. Th

Show the process of gas exchange in mammals, Q. How is gas exchange done in...

Q. How is gas exchange done in mammals? Mammals breathe through lungs their respiration is pulmonary. Q. How is circulation characterized in mammals? Mammals present a

Theory of epigenesis - pre-mendelian theory, Theor y of Epigenesis (i)...

Theor y of Epigenesis (i)          It was proposed by C.F. Wolff & supported by Von Baer. (ii)         Wolff proposed that germ cells contain definite but undifferentiated

Chorea, It is found in around 20 per cent cases of ARF and it is a late man...

It is found in around 20 per cent cases of ARF and it is a late manifestation occurring even 3 months after GAS pharyngeal infection. Chorea is triggered by emotional disturbances

Natural disasters, EARTHQUAKES          An earthquake with its terrible...

EARTHQUAKES          An earthquake with its terrible aftereffects is one of the most frightening and destructive phenomena of nature. It can be defined as a sudden movement of

Adrenal medulla, ADRENA L MEDULLA The adrenal medulla develops from th...

ADRENA L MEDULLA The adrenal medulla develops from the neuroectoderm of the embryo. Medulla consists of chromaffin cells or phaeochromocytes. These cells are connected wi

Chemical stress - atmospheric imbalances, Chemical Stress - Atmospheric imb...

Chemical Stress - Atmospheric imbalances At least two components of the environment, oxygen and carbon dioxide that plants require are predominantly in the gaseous form. As yo

Yersinia enterocolitica, Yersinia enterocolitica The genus Yersinia con...

Yersinia enterocolitica The genus Yersinia contains of 3 human pathogenic species, Y. enterocolitica, Y. pseudotuberculosis and Y. pestis, among which, Y. enterocolitica finds

Practical preparation - qualitative test for monosaccharides, Define Practi...

Define Practical Preparation - Qualitative Test for Monosaccharides? 1. Wear your labcoat. Make sure your hair is tied and you have no loose clothing. These can be dangerous in

Vegetative development - development, Vegetative Development - Development ...

Vegetative Development - Development The process of growth and differentiation of cells into organs and organisms is often termed development. For example, the development of

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