Emulsions
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dispersions of two immiscible liquids are called:
emulsions
milk is an ____ emulsion, margarine is a _____ emulsion
O/W; W/O
how to find out how much energy (delta G) that must be supplied to disperse oil phase as drops into water phase?
delta G = (interfacial tension)x (change in oil-water interfacial area)
____ are amphiphilic cules that ____ stabilize emulsions and ___ interfacial tension
emulsifiers (surfactants); kinetically; lower
what are the two types of emulsifiers?
small molecule emulsifier, polymeric emulsifier
lecithin is a ____
phospholipid
thickening agents that increase continuous phase viscosity
gums, gelatins
what are the diff emulsion destabilization mechanisms?
creaming, sedimentation, flocculation, coalescence
creaming and sedimentation is called _____
gravitational separation
what is coalescence?
fusion of two or more aggregated droplets
when is coalescence needed?
butter, whipped cream (lubricity and perceived creaminess)
emulsions are made with ___
homogenizers
nanoemulsions are made with ___
Microfluidizer (inlet reservoir–>intensifier pump–>interaction chamber)
ice cream is an example of ____ emulsion
oil and air-in water
churned cream makes ___ through oil droplet ___
buttermilk; coalescence
churned buttermilk cause ___ emulsion, draining of buttermilk from ___
W/O; butter
butter microstructure is more ___ than margarine
uniform
microstructure of ___ has highly concentrated oil droplets, providing very viscous system
mayonnaise
in ice cream and whipped cream, ____ stabilize air bubbles
fat globules