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 interaction of vitamin a with vitamin e, Explain the Interactio...

Explain the Interaction of Vitamin A with Vitamin E? Of the various nutrients, the interaction of vitamin E, proteins, zinc and iron with vitamin A is of significance. Know? Le

Can you explain anticodon, Q. How are amino acids brought to the cellular s...

Q. How are amino acids brought to the cellular site where translation takes place? What is an anticodon? Amino acids are brought to ribosomes by RNA molecules known as transfer

Inferior alveolar nerve, Inferior alveolar nerve Inferior alveolar ner...

Inferior alveolar nerve Inferior alveolar nerve repositioning to facilitate the placement of endosseous implants posterior to mental foramen is associated with very high incid

Explain in brief - chitinous, Explain in brief Chitinous? A structure w...

Explain in brief Chitinous? A structure which is composed of chitin, a complex carbohydrate composed of linearly arranged Nacetyl-glucosamine units. Chitin is a characteristic

Chlorophyll and haemoglobin, dialouge on cartoon between chlorophyll and ha...

dialouge on cartoon between chlorophyll and haemoglobin

What are the capillaries of the vascular system, What are the capillaries o...

What are the capillaries of the vascular system? Capillaries are small blood vessels that perform exchange of substances among the blood and the body tissues. Capillaries are n

Describe the functionality of pectin, Functionality Pectins are mainly ...

Functionality Pectins are mainly used as gelling agents, but can also act as a  thickener, water binder and stabilizer. Low methoxyl pectins ( 2+ ions. Highly acetylated pecti

Assessment of ventricular septal defect, Assessment   On assessment a c...

Assessment   On assessment a child with ventricular septal defect will show clinical manifestations depending upon the size of  the defect. The small defects are usually asympt

What is paediatric clinical literature, What is paediatric clinical literat...

What is paediatric clinical literature The paediatric clinical literature has expanded greatly in its coverage of the wide variety of medical circumstances that can negatively

Define proteolytic enzymes, Proteolytic enzymes They catalyze the hydro...

Proteolytic enzymes They catalyze the hydrolysis of peptide bonds in other proteins. In order to prevent them doing generalized damage to all cellular proteins, they are often

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