Starch gelatinisation Flashcards
(15 cards)
What is the process called when starch is heated in the presence of water?
Gelatinisation
Gelatinisation is essential for converting starch into sugar.
How does heat affect molecules during the gelatinisation process?
Heat causes molecules to vibrate and move, increasing movement and strain on molecular bonds.
What happens to water during the gelatinisation of starch?
Water enters the amorphous parts of the starch granule, causing it to swell and then moves into crystalline regions.
What transforms during the gelatinisation process?
Crystalline regions become amorphous, and amylose chains dissolve in water.
What is formed as a result of gelatinisation?
A gel
The gel formation allows starch to thicken sauces.
Is gelatinisation a process that occurs at a single temperature?
No, gelatinisation occurs over a range of temperatures.
What happens to spaghetti when boiled at 100°C for 10 minutes?
It continues to soften beyond 54°C.
What factors affect the gelatinisation temperatures of starch?
Cereal type, variety, and harvest conditions.
What occurs to the viscosity of the mash after starch gelatinisation?
Viscosity rapidly declines due to ɑ-amylase catalyzing starch hydrolysis.
What would happen if only β-amylase was present during starch gelatinisation?
Starch would degrade slowly into maltose units, resulting in a slower viscosity drop.
Why is the liquefaction of starch important?
It is vital for extract recovery and facilitates pumping and mixing of the mash.
What is added to cereal cookers to prevent the adjunct slurry from gelling?
Milled malt or heat-stable exogenous α-amylase.
What happens if gelatinised starch is not hydrolyzed and the temperature falls?
Starch molecules realign into a more ordered structure, known as retrogradation.
Can retrogradation occur in mashing vessels?
No, it does not occur in mashing vessels.
What can sometimes be mistaken for retrogradation during gelatinisation?
The increase in mash viscosity caused by gelatinisation without hydrolysis.
