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

How low birth weight cause protein energy malnutrition, How Low Birth Weigh...

How Low Birth Weight cause Protein Energy Malnutrition? The beginning of PEM in children starts in US from the time of their birth. At least a third of the Indian children are

Psychoactive plants of the old world, Archaeological data provide valuable ...

Archaeological data provide valuable information about the uses of plants in the past. Information comes from a number of sources, including fossil plant and human remains as well

What is the major biological function of ribosomes, Q Where in the cell can...

Q Where in the cell can ribosomes be found? What is the major biological function of ribosomes? Ribosomes can be found free in the cytoplasm, adhered to the external side of th

Spastic and obstructive constipation, Q. Spastic and Obstructive constipati...

Q. Spastic and Obstructive constipation? Spastic constipation: It results from excessive tone of the colonic muscle. Obstructive constipation: It occurs usually due to obstr

Irritability, Irritability If a bright torch of light is flashed acros...

Irritability If a bright torch of light is flashed across your eyes, you close your eyes instinctively. The bright light acts as a stimulus (pl, stimuli) and closing your eyes

Micro biology, explane the role of nitrogenase enzyme

explane the role of nitrogenase enzyme

What is a skiers launch speed, In the aerials competition in skiing, the co...

In the aerials competition in skiing, the competitors speed down a ramp that slopes sharply upward at the end. The sharp upward slope launches them into the air, where they perform

Newcastle disease / ranikhet disease (nd/rd), N e wcastle disease / Ranik...

N e wcastle disease / Ranikhet disease (ND/RD) This disease is caused by Newcastle disease virus (NDV) belonging to the genus Paramyxovirus of the family Paramyxoviridae. Alo

Infectious and inflammatory conditions for lymphatic system, Q. Why in infe...

Q. Why in infectious and inflammatory conditions may clinical signs related to the lymphatic system occur? The lymph nodes or lymph glands have lymphoid tissue that produces ly

Early-recurrence of angina, Early: Recurrence of angina soon after the pa...

Early: Recurrence of angina soon after the patient resumes activities is either due to inadequate 1.evascula1isation or acute graft closure. In the immediate post-operative per

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