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 about the derived proteins, Explain about the Derived Proteins? ...

Explain about the Derived Proteins? These are not naturally taking place proteins and are obtained from simple proteins by the action of enzymes and chemical agents, heat, mech

Ventilation of tracheal system - diffusion, Ventilation of Tracheal System ...

Ventilation of Tracheal System - Diffusion Gaseous exchange due to diffusion generally takes care of the oxygen needs of most small insects. Similarly fairly large but inactiv

Define the coenzyme activity of nicotinic acid, Define the Coenzyme activit...

Define the Coenzyme activity of nicotinic acid? Nicotinamide exists within the redox-active coenzymes,  nicotinamide adenine dinucleotide (NAD) and its phosphate (NADP), which

Nursing care plan, Mrs. TT seventy three-year old has a long history of chr...

Mrs. TT seventy three-year old has a long history of chronic obstructive pulmonary disease (COPD). She came to the medical ward as shortness of breath, wheezing and a cough for the

Human aging, what is the process called free radicals damage body molecules...

what is the process called free radicals damage body molecules

Taxonomy, What category do pisces, mammalla, amphibia, reptilia and aves fa...

What category do pisces, mammalla, amphibia, reptilia and aves fall into

Human chromosomes, HUMA N CHROMOSOMES The normal diploid (2N) chromoso...

HUMA N CHROMOSOMES The normal diploid (2N) chromosome number in human being is 46. It was given by T.H. Tjio and A. Levan in 1956. The chromosome complement of a cel

The main causes of the loss of biological diversity, What are the main caus...

What are the main causes of the loss of biological diversity nowadays? The biggest dangers to biological diversity today are the action of humans. The most of them is the destr

Explain red anthocyanin pigments, Explain Red anthocyanin pigments Red ...

Explain Red anthocyanin pigments Red anthocyanin pigments from miracle fruit were isolated and tested in carbonated beverages, in combination with the organic acids. Pigments d

Explain sickle cell anemia, Explain Sickle cell anemia If 4% of a peopl...

Explain Sickle cell anemia If 4% of a people are born with a severe form of sickle cell anemia. what percent of population will be resistant to malaria in spite of carrying

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