It is recognisable by an off odour and off taste caused by oxygen in the air, moisture, heat, or certain enzymes present in many natural fats. The chemicals used by food processors to control rancidity are few in number. There are many other chemicals used as food additives for particular purposes. Anti-caking agents are added to powder food to prevent caking of food. Emulsifiers are substances which are capable of aiding the formation of a uniform dispersion of two or more immisible substances.
Stabilisers are substances which are capable of maintaining such uniform dispersion.
Humectant means any substance which, when added to food, absorbs moisture and maintains the water content of the food. Sequestrants are substances which, when added to food, combines with a metal ion in the food and renders the metal ion inactive. A leavening is any chemical that can produce bubbles of gas in dough. Chemicals allow food to be more easily handled by automatic machinery. Every meal you eat is almost certain to contain small amounts of a variety of chemicals, added to the food for a variety of reasons.