Cooking techniques / solubility of powders

Question 1

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

Answer 1

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

Question 2

can you represent how the powder are solubilised

Answer 2

Question 3

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

Answer 3

complete

Question 4

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

Answer 4

dewetting

Question 5

The moisture transport is dependent on ____

Answer 5

the state of the material:

Question 6

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

Answer 6

1- capillary diffusion
2- molecular diffusion

Question 7

What is capillary diffusion ?

Answer 7

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

Question 8

what is molecular diffusion ?

Answer 8

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

Question 9

whasburn equation is related to the ____ of the diffusion

Answer 9

capillary diffusion

Question 10

youngs equation is related to the ____ of the dissolution

Answer 10

wetting step

Question 11

what can you know from the washburn equation?

Answer 11

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

Question 12

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

Answer 12

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

Question 13

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

Answer 13

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

Question 14

what can be done to increase the dissolution rate ?

Answer 14

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)

Question 15

what is the anti-griddle ?

Answer 15

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

Question 16

what is malto by texturas ?

Answer 16

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

Question 17

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

Answer 17

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

(not for green vegetable, turn brown without oxygen)

• Create different shapes

Question 18

what are the advantages of sous vide cooking ?

Answer 18

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

Question 19

transglutaminase needs proteins with a.a. ___ to work

Answer 19

glutamine and it will form a strong covalent bond without heat

Question 20

what is the vaporiser ?

Answer 20

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

Question 21

what is vaccuum impregnation?

Answer 21

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

Question 22

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

Answer 22

the vaccuum fusing (vaccuum impregnantation)

Question 23

can you link this figure with the crunchiness sensorial sensation?

Answer 23

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

Question 24

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

Answer 24

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.