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

Pyramid of energy - ecological pyramids, Pyramid of Energy - Ecological Pyr...

Pyramid of Energy - Ecological Pyramids When we wish to compare the functional roles of the trophic levels in an ecosystem, an energy pyramid is probably the most informative.

Agricultural activities - cause of air pollution, Agricultural activities -...

Agricultural activities - Cause of Air Pollution Agricultural activities too are a major cause of air pollution. About 60 to 65% of carbon dioxide is produced from burning of

Significance of mitosis, Significance of Mitosis 1.      Reproduction ...

Significance of Mitosis 1.      Reproduction ;   William Bateson 1906 wrote, Whenever  I observe a dividing  cell under  the  microscope , I feel  as if the original act of  c

What is simple transposition in neonates, What is Simple Transposition in N...

What is Simple Transposition in Neonates ? A baby with this malformation needs to be operated without delay. A very cyanosed infant will require palliation by balloon arteries

What is carbohydrates, What is Carbohydrates? Carbohydrates : Carbohyd...

What is Carbohydrates? Carbohydrates : Carbohydrates function mainly as immediate sources of energy, stored energy such as starch, and structural components of cells. Carbohyd

Explain food applications of agar, Food Applications of Agar The bakery...

Food Applications of Agar The bakery industry has been the largest user  of agar because of its heat- resistant gel properties. Confectionary products, such as agar jelly candi

Define urinary excretion test - thiamin status, Define Urinary Excretion Te...

Define Urinary Excretion Test - Thiamin Status? The urinary excretion of thiamin is an index of recent dietary intake of the vitamin. Hence, determination of thiamin in urine s

Detection of pulmonary hypertension, Pressure calculation made using the Be...

Pressure calculation made using the Bernoulli equation may be used  in conjunction with pressure measurements made by other modalities to determine various intracardiac pressure.

Explain hiv/aids, Explain HIV/AIDS HIV/AIDS is another example of  chro...

Explain HIV/AIDS HIV/AIDS is another example of  chronic infections.  Its existence was discovered recently in 1981. The spread  of  HIV infection  is widespread  and  can  pro

Anatomy in relation to taxonomy, Q. Anatomy in relation to taxonomy? Th...

Q. Anatomy in relation to taxonomy? The use of anatomical* characters in taxonomy began with the development of the microscope which provided the biologist a new tool to observ

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