# Cooking techniques / solubility of powders Flashcards

1
Q

what are the steps involved in the dissolution / dispension of powders ?

A

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

2
Q

can you represent how the powder are solubilised

A
3
Q

When the angle is of 0˚c, there is ____ wetting

A

complete

4
Q

when the angle is of 180˚C between the solvent and the particle, there is ___ wetting

A

dewetting

5
Q

The moisture transport is dependent on ____

A

the state of the material:

6
Q

What are the two regimes for the diffusion step of the water uptake?

A

1- capillary diffusion
2- molecular diffusion

7
Q

What is capillary diffusion ?

A

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

8
Q

what is molecular diffusion ?

A

2- molecular diffusion iis more related to the trasnfer of the water over time by migration.

9
Q

whasburn equation is related to the ____ of the diffusion

A

capillary diffusion

10
Q

youngs equation is related to the ____ of the dissolution

A

wetting step

11
Q

what can you know from the washburn equation?

A

you could know by the water uptake the porosity of a certain sample

12
Q

T or F : two solvent can have the same contact angle but there could still be differences in their rate of dissolution

A

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

13
Q

lower is the surface tension, ___ is the contact angle and this results in ____ wetting

A

smaller is contact angle (higher COS(0)) and this results in increased rate of wetting

14
Q

what can be done to increase the dissolution rate ?

A

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)

15
Q

what is the anti-griddle ?

A

a freeze griddle at -43˚C which can freeze what is put on top of it

16
Q

what is malto by texturas ?

A

a maltodextrin that is really amorphous and hydroscopic so it can turn every oil into a solid version, it has no taste

17
Q

what are the effect that sous-vide cooking can have on the color of fruits and vegetables ?

A
• Compression of porous fruits (translucent)
• Prevent discoloration of fruit (no oxygen)

(not for green vegetable, turn brown without oxygen)

• Create different shapes
18
Q

what are the advantages of sous vide cooking ?

A

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

19
Q

transglutaminase needs proteins with a.a. ___ to work

A

glutamine and it will form a strong covalent bond without heat

20
Q

what is the vaporiser ?

A

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

21
Q

what is vaccuum impregnation?

A

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

22
Q

what cooking technique is used in the case of the edible cocktail ?

A

the vaccuum fusing (vaccuum impregnantation)

23
Q

can you link this figure with the crunchiness sensorial sensation?

A

when hypotonic and hypertonic you will reduce the crispniess and the isotonoc solution will keep or increase the crispiness.

24
Q

what is the effect of adding alcohol in the surrounding environment of a fruit/vegetables during vaccuum impregnation?

A

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.