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

Functions of gluconeogenesis, Functions of Gluconeogenesis The signifi...

Functions of Gluconeogenesis The significance of gluconeogenesis include: 1)  During starvation or during periods of  limited  carbohydrate intake, when  the levels of liv

List some points to keep in mind while counselling, Q. List some points to ...

Q. List some points to keep in mind while counselling? 1. Judgment Do not be judgemental. Be a patient listener. Assess and make decision. 2. Patience and Acceptance

Rectum examination of new born, Rectum check for anal patency and p...

Rectum check for anal patency and passage of meconium and observe whether meconium is passed or not. Confirm its patency then pass a catheter or gloved finger  check if

Muscular force, 2.?In order to increase muscular force production, muscular...

2.?In order to increase muscular force production, muscular contractions may be modulated in two ways. Explain.

Vasodilatation from the time of injury, The blood vessels surrounding an ac...

The blood vessels surrounding an acutely inflamed site usually represent progressive vasodilatation from the time of injury.

Optional use values of biodiversity, Q. Optional use values of biodiversity...

Q. Optional use values of biodiversity? Optional values are associated with potential use in the future. Accordingly one opts to conserve biodiversity based on the hope that it

Excretory system, what is the excretory organ of agama lizard

what is the excretory organ of agama lizard

What are flight adaptations present by birds, Q. What are flight adaptation...

Q. What are flight adaptations present by birds? Wings associated to a well-developed pectoral musculature, less accumulation, pneumatic bones of feces in the bowels due to the

What are primary consumers, What are primary consumers? Can a food chain pr...

What are primary consumers? Can a food chain present quaternary consumers without having secondary or tertiary consumers? Can a tertiary consumer of one chain be a primary or secon

Define interaction of folate with vitamin c, Define Interaction of Folate w...

Define Interaction of Folate with Vitamin C? Vitamin C: Anaemia is observed in vitamin C deficient patients. Normochromic, normocytic or macrocytic or megaloblastic ana

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