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 infections and infestations cause pem, How Infections and Infestations ...

How Infections and Infestations cause PEM? Childhood infections (viral/bacterial) and parasitic infestations are almost always associated with PEM. These cause anorexia (loss o

Physical properties of carbohydrates, PHYSICA L PROPERTIES All mono...

PHYSICA L PROPERTIES All monosaccharides which have an asymmetric carbon are able to rotate polarized light either to left side ( laevorotatory ) or right side ( dextroro

Define salient modifiable factors which affect birth weight, Define salient...

Define salient modifiable factors which affect birth weight? The following are the salient modifiable factors which affect birth weight and gestation adversely: Iron deficiency

What is ecosystem, Question 1 Write a short note on the following         ...

Question 1 Write a short note on the following                       1 Angiosperms                       2 Meristematic tissue Question 2 What is ecosystem? List and explain

Show the stages in which the cell respiration is divided, Q. What are the t...

Q. What are the three stages into which the cell respiration is divided? The three stages of aerobic cell respiration are glycolysis, Krebs cycle and respiratory chain also kno

Aeromonas associated zoonotic disease, Aeromonas associated zoonotic diseas...

Aeromonas associated zoonotic disease Aeromonas causes gastrointestinal infections and extra intestinal infections such as cellulitis, wound infectiopn, peritonitis, endocardi

Poultry and duck diseases-avian adenovirus infections, Avian adenovirus inf...

Avian adenovirus infections EDS-76, an adenovirus, has been etiologically associated with drop in egg production. Other adenoviruses affecting chicken and other birds include

Phylum porifera, harmful and beneficial usesa of phylum porifera

harmful and beneficial usesa of phylum porifera

Precaution - separation of amino acid by paper chromatogrphy, Define Precau...

Define Precaution for Separation of Amino Acids by Paper Chromatography? 1. Hold the paper with the extra strip kept at one side. Handling of whatman paper with hand should be

Proto-oncogenes, Proto-oncogenes Proto-oncogenes are common genes pre...

Proto-oncogenes Proto-oncogenes are common genes present. In all organisms and emerge to be highly conserved in the course of evolution. They have been isolated in species ra

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