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

Give advantage and disadvantage of asexual reproduction, What are one advan...

What are one advantage and one disadvantage of asexual reproduction compared with sexual reproduction? The benefit of asexual reproduction is that off- spring are genetically

Genetic defect in pyruvate dehydrogenase, Genetic Defect in Pyruvate Dehydr...

Genetic Defect in Pyruvate Dehydrogenase A defed in any of  the protein subunits of PDH can result in decrease or complete loss of  activity. Severe cases are usually fatal. Sy

Explain what is aortic arch aneurysm, Explain what is Aortic Arch Aneurysm ...

Explain what is Aortic Arch Aneurysm ? Aortic Arch Aneurysm :  Hypothermic circulatory arrest and retrograde cerebral perfusion is the most commonly used technique for

Define comprehensive dietary management regime of patient, Define Comprehen...

Define Comprehensive Dietary Management Regime of Patient? A comprehensive dietary management regime of the patient should be based on the patient profile as gathered pre and p

How many progeny flies have vestigial wings, In the fruit fly Drosophila, a...

In the fruit fly Drosophila, a rudimentary wing called "vestigial" and dark body color called "ebony" are inherited at independent loci and are recessive to their dominant wild-typ

Define advantages of blanching, Define Advantages of Blanching? Blanch...

Define Advantages of Blanching? Blanching as a pre-treatment before drying has the following advantages: 1. It helps in cleaning the material and reducing the amount

Phases of menstrual cycle - reproduction, Phases of Menstrual Cycle - Repro...

Phases of Menstrual Cycle - Reproduction Four phases of the menstrual cycle are usually distinguished: the menstrual, proliferative (follicular), ovulatory and progestational

Protein necessity, Proteins necessity They are called as body builde...

Proteins necessity They are called as body builders. The proteins are used in various metabolic pathways and body building. They help in repairing the tissues of the b

Define the properties of fibre, Define the Properties of Fibre? The str...

Define the Properties of Fibre? The structural make up of fibre influences its properties which in turn affects the physiologic and metabolic roles. This is well-depicted in th

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