Emulsions, Foams and Gels

Emulsion refers to combining fat and water

A foam is a substance that is formed by trapping many gas bubbles in a liquid or solid

A gel is a sol in which the solid particles are meshed such that a rigid or semi-rigid mixture results. Cross-linking within the gel’s polymer or colloidal network causes a gel to behave as a solid in its steady-state and makes it feel tacky.

Milk Hollandaise Mayonnaise Aioli Cream

Stability • flocculation • creaming • coalescence • Oswald ripening

Causes food spoilage, which is less attractive to the consumer

Adding a biopolymer, emulsifier, texture modifier, ripening inhibitor, and weighting agent

Phospholipid Polar and non polar groups form a monolayer

To reduce surface tension

Good emulsifying capacity Able to lower the interfacial tension in order to lessen the energy needed to produce particles

Assess any changes in dispersion, changes on the droplet Through centrifugation and heating

Van de Waals interactions Electrostatic repulsion

Not stable Rigid Elastic Brittle

seaweed

Trees, seeds, fruit

Cosmetic products

Yes

Temperature Chemical alteration Addition of water

The resistance to flow

Capillary viscometer

Rotational viscometer

Newtonian flow Pseudoplastic flow Dilanant flow Bingham flow

To make specialised products To assess texture of food

Unstable