Cooking techniques / solubility of powders Flashcards
what are the steps involved in the dissolution / dispension of powders ?
1- wetting of the powder by the solvent 2-diffusion of the solvent into the powder 3-complete dissolution of the powder into the solvent
can you represent how the powder are solubilised
When the angle is of 0˚c, there is ____ wetting
complete
when the angle is of 180˚C between the solvent and the particle, there is ___ wetting
dewetting
The moisture transport is dependent on ____
the state of the material:
What are the two regimes for the diffusion step of the water uptake?
1- capillary diffusion
2- molecular diffusion
What is capillary diffusion ?
1- the initial uptake and it is how the liquid is sucked into the product and it is more related to the porosity of the product
what is molecular diffusion ?
2- molecular diffusion iis more related to the trasnfer of the water over time by migration.
whasburn equation is related to the ____ of the diffusion
capillary diffusion
youngs equation is related to the ____ of the dissolution
wetting step
what can you know from the washburn equation?
you could know by the water uptake the porosity of a certain sample
T or F : two solvent can have the same contact angle but there could still be differences in their rate of dissolution
true, alcohol and water have the same contact angle at a certain point but the rate of dissolution of cocoa particles in alcohol is higher than in water because the surface tension is more impportant since it is related to the wetting in the first place
lower is the surface tension, ___ is the contact angle and this results in ____ wetting
smaller is contact angle (higher COS(0)) and this results in increased rate of wetting
what can be done to increase the dissolution rate ?
1 - increase agitation
2- change of liquid (which changes the contact angle)
3- addition of an emulsifier (which reduces the surface tension and changes the wetting by changing the contact angle)
what is the anti-griddle ?
a freeze griddle at -43˚C which can freeze what is put on top of it
what is malto by texturas ?
a maltodextrin that is really amorphous and hydroscopic so it can turn every oil into a solid version, it has no taste
what are the effect that sous-vide cooking can have on the color of fruits and vegetables ?
- Compression of porous fruits (translucent)
- Prevent discoloration of fruit (no oxygen)
(not for green vegetable, turn brown without oxygen)
- Create different shapes
what are the advantages of sous vide cooking ?
increases the efficiency of marinades
compression / vaccum can change the texture
cook before serving and finished last minute
less people-power
consistency of the cooking temperature and optimal temp
sealing prevents the oxidation
increases the shelf-life
transglutaminase needs proteins with a.a. ___ to work
glutamine and it will form a strong covalent bond without heat
what is the vaporiser ?
a vaporiser that vaporise flavours and add them to a bag containing the food, the diffusion of the flavour will depends on the diffusion kinetics
what is vaccuum impregnation?
you marinate under a vaccuum and so the air will expand and excape and when the pressure is restored the gas compression will make a suction of the liquid
what cooking technique is used in the case of the edible cocktail ?
the vaccuum fusing (vaccuum impregnantation)
can you link this figure with the crunchiness sensorial sensation?
when hypotonic and hypertonic you will reduce the crispniess and the isotonoc solution will keep or increase the crispiness.
what is the effect of adding alcohol in the surrounding environment of a fruit/vegetables during vaccuum impregnation?
you alsways loose the crunchiness because you reuce the solubility of the polysaccharide in the lammella and so the whole system collapse and becomes softer. So based on structure you will reduce the pressure and fracture thoughness.
