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

Medical management of chronic renal failure, Medical Management   In ch...

Medical Management   In chronic  renal failure  there  is irreversible renal failure. The goals of medical management are:   To promote maximal  renal  function  To ma

Define evolution of food processing, Define Evolution of food processing? ...

Define Evolution of food processing? 8000 - 7000 BC. Mankind first began farming, growing crops and raising animals for food instead of hunting and gathering for food.

hypotheses testing, Celia is a nurse in a geriatric ward.  She noticed tha...

Celia is a nurse in a geriatric ward.  She noticed that older persons in her care are having problems sleeping at night.  She decided to introduce non-pharmocologic ways of relaxat

Can you explain about ventriculography, Q. Can you explain about Ventriculo...

Q. Can you explain about Ventriculography? Cardiac ventriculography is a diagnostic test, i.e., used to define the anatomy and function of the ventricles (left and right) and r

What is karyotype, What is karyotype? The name karyotype is given to th...

What is karyotype? The name karyotype is given to the set of chromosomes of an individual, generally when visualized and identified under the microscope. The visualization usua

What are pioneer species, What are pioneer species? What is the role of the...

What are pioneer species? What is the role of the pioneer species? Pioneer species are those first species that colonize places where before there were no living beings, like,

Surface Processes on Earth, Which of the following is not a type of mass mo...

Which of the following is not a type of mass movement that results from the force of gravity? A. Landslide B. Creep C. Deflation D. Mudflow

Is it necessary for blood to have less or more hemoglobin, Q. In high altit...

Q. In high altitudes is it necessary for the blood to have less or more hemoglobin? In high altitudes the oxygen concentration and air is rarefied is lower than in low altitude

Explain mixture in basic chemistry, Explain mixture in basic chemistry? ...

Explain mixture in basic chemistry? Mixtures :  Mixtures are produced by combining two or more substances. In contrast to the substances in compounds, the substances that com

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