A brief introduction to food emulsion.

1. 1
FOOD EMULSIONS
Abd Karim Alias, 2013©
Prof. Abd Karim Alias
Universiti Sains Malaysia
Photo
courtesy
of
Tim
Sackton
on
Flickr

2. 2
} An emulsion consists of two
immiscible liquids (oil & water),
with one of the liquids dispersed
as small spherical droplets in the
other.
} In foods, the diameter of these
droplets usually falls somewhere
in the range 0.1 – 100 µm.
Food Emulsion
Abd Karim Alias, 2013©

3. 3
} Two types of simple emulsion:
} Water-in-oil (w/o): margarine,
butter, spreads
} Oil-in-water (o/w): mayonnaise,
salad dressings, milk, beverages,
cream, soups, sauces
} The dispersed and/or continuous
phase of many food emulsions may
be partly crystalline, rather than
being completely liquid.
Food Emulsion
Abd Karim Alias, 2013©

4. 4
} Emulsion formation requires the
dispersion of one phase into small
droplets ⇒ this results in a massive
increase in interfacial area between the
dispersed & continuous phase.
} Homogenization is the process by which
the dispersed phase is broken into small
droplets; high pressure homogenizers (10
– 100 MPa) are now very common.
Formation of Emulsion
Abd Karim Alias, 2013©

5. 5
Formation of Emulsion
Abd Karim Alias, 2013©

6. 6
Formation of Emulsion
Ì
Shear force
Abd Karim Alias, 2013©

7. 7
Importance of Large Interfacial Area
For a fixed composition:
• Decrease size, increase number of
particles
• Increase area of interfacial contact
Increase area
Abd Karim Alias, 2013©

8. 8
Formation of Emulsion
Abd Karim Alias, 2013©