Question

What is the difference between oil/water (O/W) type and water/oil (W/O) type emulsions? Give an example of each type.

Answer 1

In an oil-in-water emulsion, the continuous phase is the water and the dispersed phase is the oil while in a water-in-oil emulsion the oil is the continuous phase. Oil-in-water emulsions are common in food products.
a. Cream (foam) in espresso – coffee oil in water (brewed coffee).
b. Homogenized milk – an emulsion of milk fat in water and milk proteins.
Water-in-oil emulsions are less common in food.
c. Butter – an emulsion of water in butterfat.