Carbohydrates / Polysaccharides - Storage polysaccharides - Chemical modification
23 important questions on Carbohydrates / Polysaccharides - Storage polysaccharides - Chemical modification
Why do you modify starch under 50 degrees?
What are the things that make chemical modification difficult?
- Different ‘reactivity’ depending on granule size
- Crystalline versus amorphous regions
- Amylose versus amylopectin (amylose is more easy to modify)
- Distribution within the amylose/amylopectin molecule
How do you crosslink your starch?
At pH11.5 it will make a phosphore ester and this makes that the starches can be linked at certain places.
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What is the effect of crosslinking starch?
- They also keep swollen granules intackt
- Prevent loss of viscosity
- Resistant to mechanical shear
- more stable in acid conditions
What is the reason behind the effects of crosslinked starch?
This results in a stabler product since it is hard to break the granulas.
Why do you often do more modifications then only crosslinking?
What are stabilisation reactions?
What is the degree of subsitution?
What are the places which can have a substituent in a glucose molecule in a starch chain?
How do they call starch that had a esterification step?
What are the reactions occuring during esterification of starch?
What is the effect on viscosity of acetylated corn starch?
What is succinate starch?
What are the properties of succinate starch?
It also increases the viscosity
By what can you controll the properties of succinate starch?
Low pH less coo- loading so less viscous solution
High pH more coo- loading so more viscous solution.
High salt neutralises coo- loading so less viscous
How do you get starch monophosphate?
Same properties as succinate starch due to charge.
What is the difference in stability between a ester and ether linkage in starch?
What are the improvements that etherification gives to starch?
It limits the tendency of cold retrogradation.
less degradable by enzymes
What is the special property of hydropropyl starch?
How can you give hydropropyl starch a hydrophobic caracter?
How can you control the viscosity of hydroxypropyl starch?
What is cationization of starch?
What are the properties of cationization of starch?
higher peak viscosity
applications in paper indsutry.
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