Emulsions

Question 1

dispersions of two immiscible liquids are called:

Answer 1

emulsions

Question 2

milk is an ____ emulsion, margarine is a _____ emulsion

Answer 2

O/W; W/O

Question 3

how to find out how much energy (delta G) that must be supplied to disperse oil phase as drops into water phase?

Answer 3

delta G = (interfacial tension)x (change in oil-water interfacial area)

Question 4

____ are amphiphilic cules that ____ stabilize emulsions and ___ interfacial tension

Answer 4

emulsifiers (surfactants); kinetically; lower

Question 5

what are the two types of emulsifiers?

Answer 5

small molecule emulsifier, polymeric emulsifier

Question 6

lecithin is a ____

Answer 6

phospholipid

Question 7

thickening agents that increase continuous phase viscosity

Answer 7

gums, gelatins

Question 8

what are the diff emulsion destabilization mechanisms?

Answer 8

creaming, sedimentation, flocculation, coalescence

Question 9

creaming and sedimentation is called _____

Answer 9

gravitational separation

Question 10

what is coalescence?

Answer 10

fusion of two or more aggregated droplets

Question 11

when is coalescence needed?

Answer 11

butter, whipped cream (lubricity and perceived creaminess)

Question 12

emulsions are made with ___

Answer 12

homogenizers

Question 13

nanoemulsions are made with ___

Answer 13

Microfluidizer (inlet reservoir–>intensifier pump–>interaction chamber)

Question 14

ice cream is an example of ____ emulsion

Answer 14

oil and air-in water

Question 15

churned cream makes ___ through oil droplet ___

Answer 15

buttermilk; coalescence

Question 16

churned buttermilk cause ___ emulsion, draining of buttermilk from ___

Answer 16

W/O; butter

Question 17

butter microstructure is more ___ than margarine

Answer 17

uniform

Question 18

microstructure of ___ has highly concentrated oil droplets, providing very viscous system

Answer 18

mayonnaise

Question 19

in ice cream and whipped cream, ____ stabilize air bubbles

Answer 19

fat globules