3.  Van der waals attractive force is tends to
destabilise colloids.
 Electrostatic repulsive forces is generally
impart stability.

4.  DLVO stand for Derjaguin-Landau-Verwey-Overbeek)
 Colloid stability proposes a balance of the :
repulsive electric double layer forces (+ve by
convection)
attractive Van Der Walls force (-ve by convection)
 In the other word, the DLVO theory states that the
stability of a colloidal suspension depends on the net
interaction forces between the dispersed particles :
Van Der Walls force of attraction
The electrostatic repulsion between electrical double
layers of identical sign

5.  Region of unequal counter and co ion
concentrations near the surface.
 Regarded as consisting of two regions :
An inner region of strongly adsorbed ions
Outer region where ions are diffusely
distributed according to a balance between
electrical forces and random thermal motion.

6.  The formation of a double layer is very
important for the stability of the colloid.
 The double layer is sensitive to electrolytes
and also temperature.
 This means that the stability of the colloid
may be manipulated by adding electrolytes
or changing the temperature

7.  Electrical potential on the surface of the
diffuse layer i.e. slipping plane(hydronamic
plane of shear).
 At some point out in the double layer
region,corresponding more or less to the
potential at the zone of shear,electrical
potential.
 Value : < -15mV ( represent onset of
flocculation)

8.  Value more negative than 130mV (stability
dividing line)
 Range -15mV to -30mV cannot categorically
state –emulsion will or not be stable at given
zeta potential

9.  Lower the concentration of inorganic
electrolytes (salts), the higher will be the
repulsive energy and the more stable the
emulsion toward flocculation (aggregation).
 Compromises between flavour and stability.
 When ( salt ) more certain critical value
( depends on type of food system ) thickness of
double layer.
 Will decrease- chances for droplets come close
together increase.
 When ( salt ) less than critical value, optimum
thickness of double layer obtained, so emulsion
is stabilize.

10.  Compressed by the the salt and hydrogen
ion concentration .
 Make the repulsive force ineffective .
 Droplet charge decrease stabilized
emulsions-ph tends toward isoelectric point.
 Protein stabilized emulsions become
aggregate when ph adjust protein isoelectric
point.