"A food additive is any chemical substance that is added to food during preparation or storage and either becomes a part of the food or affects its characteristics for the purpose of achieving a particular technical effect." [Source]

"Examples of food additives include colouring agents that give foods an appetizing appearance, anticaking agents that keep powders such as salt free-running, preservatives that prevent or delay undesirable spoilage in food, and certain sweeteners that are used to sweeten foods without appreciably adding to the caloric value of the foods.

Under the Food and Drug Regulations, food additives do not include:

• food ingredients such as salt, sugar, starch;
• vitamins, minerals, amino acids^Footnote1;
• spices, seasonings, flavouring preparations;
• agricultural chemicals;
• veterinary drugs; or
• food packaging materials." [Source]

"Food additives are substances added intentionally to foodstuffs to perform certain technological functions, for example to colour, to sweeten or to help preserve foods.

In the European Union all food additives are identified by an E number . Food additives are always included in the ingredient lists of foods in which they are used. Product labels must identify both the function of the additive in the finished food (e.g. colour, preservative) and the specific substance used either by referring to the appropriate E number or its name (e.g. E 415 or Xanthan gum). The most common additives to appear on food labels are antioxidants (to prevent deterioration caused by oxidation), colours, emulsifiers, stabilisers, gelling agents and thickeners, preservatives and sweeteners." [Source]

 "A food additive is defined in Section 201(s) of the FD&C Act as any substance the intended use of which results or may reasonably be expected to result, directly or indirectly, in its becoming a component or otherwise affecting the characteristic of any food (including any substance intended for use in producing, manufacturing, packing, processing, preparing, treating, packaging, transporting, or holding food; and including any source of radiation intended for any such use); if such substance is not GRAS {Editorial Note: GRAS stands for generally recognized as safe} or sanctioned prior to 1958 or otherwise excluded from the definition of food additives." [Source]