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

Explain the characteristics of cancer, Explain the Characteristics of Cance...

Explain the Characteristics of Cancer? The important characteristics of cancer are excessive cellular multiplication, invasiveness and autonomy. The active process of invasion

Anatomy of the brain, In order to be able to study the neural basis of perc...

In order to be able to study the neural basis of perceptual and cognitive functions, it is necessary to have some knowledge of brain anatomy (i.e., what the names of different brai

Progeny of a single cross between two mountain rabbits, In mountain rabbits...

In mountain rabbits, the EL-1 gene is located on chromosome 3. Four alleles of this gene have been identified in the population. With respect to EL-1, what is the maximum number of

Treatment of angina pectoris, Q. Treatment of angina pectoris? Proper a...

Q. Treatment of angina pectoris? Proper and careful treatment of the underlying cause (usually dyslipidemia, advanced atherosclerosis or sever chronic hypertension) is imperati

Define initiation phase - mechanism of protein synthesis, Define Initiation...

Define Initiation phase - mechanism of protein synthesis ? The assembly of a ribosome on an mRNA molecule at the correct start point, the initiation codon. Three initiation fac

What is a species?, What is a species? The species is a set of living b...

What is a species? The species is a set of living beings able to cross among themselves generating fertile offspring. This concept though does not apply to individuals of ex

Speciation, SPECIATION - Origin of new species: An isolated popula...

SPECIATION - Origin of new species: An isolated population of a species independently develops different types of mutations. The later accumulate in its gene pool. Afte

Define feeding for infants of hiv/aids mothers, Define Feeding for Infants ...

Define Feeding for Infants of HIV/AIDS Mothers? It is recommended to continue breast-feeding even if the disease will continue to be transmitted. If these infants are not breas

Cells, What surrounds a plant cell

What surrounds a plant cell

Phylum protozoa, classification of organisms in phylum protozoa according t...

classification of organisms in phylum protozoa according to their class,order,family,genus,species.

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