Type of Emulsion in Butter

Butter is which type of emulsion?

Correct Answer: Water in fat

Butter is a water-in-fat (W/O) emulsion — tiny water droplets are dispersed within a continuous fat phase. This is the opposite of milk (fat-in-water).

Phase Inversion During Butter Making

• When cream (fat-in-water) is churned, a phase inversion occurs.
• The fat globule membrane breaks, fat globules clump together, and small water droplets become trapped within the fat mass.
• This converts the fat-in-water emulsion of cream into the water-in-fat emulsion of butter.

Composition of Butter

• Contains all fat-soluble vitamins: Vitamin A, D, E, and K.
• Flavouring agent: Diacetyl (≤4 ppm).
• Yellow colour: Due to Annatto (added colouring agent).
• Fishy odour in butter: Due to rancidity.
• Best method of ghee making: Pre-stratification method.

Emulsion Summary

• Milk, Cream → Fat in water (O/W)
• Butter → Water in fat (W/O)