Exam 1: Food Dispersions

Question 1

sol:

Answer 1

solid dispersed in a liquid

ex: gelatin

Question 2

gel:

Answer 2

liquid dispersed in a solid

ex: jell-o, syneresis

Question 3

continuous phase:

Answer 3

j

Question 4

discontinuous phase:

Answer 4

y

Question 5

factors affecting solubility:

Answer 5

temp: higher temp = > solubility

Question 6

emulsifiers:

Answer 6

• a substance that stabilizes an emulsion, in particular a food additive used to stabilize processed foods.
• help two liquids coalesce that would otherwise would not
  
  • need energy: kinetic (whip, stir, blend) to allow to coalesce

Question 7

emulsifying agents:

Answer 7

egg yolk: lecithin (polar molecules) orient fat molecules
mustard (little bit of lecithin: wet & dry)
fine powders: coat surface (milk powder, paprika)

Question 8

different types colloidal dispersions:

Answer 8

(1) gel
(2) sol
(3) foam
(4) suspensoid
(5) emulsion

Question 9

foam:

Answer 9

gas dispersed in a liquid

ex: egg white

Question 10

suspensoid:

Answer 10

gas in a solid

ex: pulp (core suspenison), cake, mousse

Question 11

emulsions:

Answer 11

liquid in a liquid (normally immiscible)
mixture of two liquids that would otherwise would not be
ex: vinegarette, hollandaise

Question 12

solubility:

Answer 12

ability of a solution to intake a solute