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

Tingling or numbness in hands - symptoms of diabetes, Tingling or numbness...

Tingling or numbness is seen in cases of neuropathy. It occurs gradually over time. As high sugar (glucose) in the blood damages the nervous system, particularly in the extremities

What are the uses of whey protein concentrates, What are the uses of whey p...

What are the uses of whey protein concentrates? Whey protein concentrates are used extensively in the manufacture of baked goods, where they increase the effectiveness of short

Explain lateral meristem, Which one of the following is not a lateral meris...

Which one of the following is not a lateral meristem? 1. Intrafascicular cambium 2. Interfascicular cambium 3. Phellogen 4. Intercalary meristem   Intercalary m

Homeostasis, why should shivering contribute to heat gain in the body?

why should shivering contribute to heat gain in the body?

Which amino acid can form disulfide bonds, a. Which amino acid can form dis...

a. Which amino acid can form disulfide bonds? b. Which level of protein structure do disulfide bonds affect? How? c. Cytoplasmic proteins rarely form disulfide bonds, even if they

What are the plant hormones, What are the plant hormones? The Plant hor...

What are the plant hormones? The Plant hormones also called as phytohormones, are the substances that control the embryonic development and the growth of the adult plant.

Absorption of lipids, Absorption of lipids Absorption of lipids is qui...

Absorption of lipids Absorption of lipids is quite different from the absorption of monosaccharides and amino acids. Figure shows the process. The free fatty acids, monoglycer

Science class, Im learning about difference cell structures in science. I w...

Im learning about difference cell structures in science. I was wondering if I might be able to get some information about the epithelial tissue, and the connective tissue. Thankyou

Define chlorophyll - natural colourant, Chlorophyll Chlorophyll is the...

Chlorophyll Chlorophyll is the porphyrin most widely used as a natural colourant. Its widespread occurrence in photosynthetic  tissue and its breakdown character have prompted

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