Composition
Ice cream is a colloidal emulsion having dispersed phase as fat globules. It is an emulsion which is in the end made into foam by incorporating air cells which is frozen to form dispersed ice cells. In the composition of ice cream ice crystals are of most importance as they give a desirable mouth feel. Ice cream is composed of water, ice, milk fat, milk protein, sugar and air. Water and fat have highest proportions by weight creating an emulsion. The triacylglycerols in fat are non polar and will adhere to itself by van der Waals interactions. Water is polar thus, emulsifiers are needed for dispersion of fat. Also ice cream has a colloidal phase of foam which helps in light texture. Milk proteins such as casein and whey protein present in ice cream are amphiphilic, can adsorb water and form micelles which will contribute to consistency. Sucrose which is disaccharide is usually used as a sweetening agent. Lactose which is sugar present in milk will cause freezing point depression. Thus, on freezing some water will be unfrozen and will not give hard texture.
