ETYM Latin additivus.
Characterized or produced by addition.
Pertaining to addition; Grammar, signifying addition of similar elements or of new thought; Philosophy, marked by addition rather than union.

Plural: additives

In food, any natural or artificial chemical added to prolong the shelf life of processed foods (salt or nitrates), alter the color or flavor of food, or improve its food value (vitamins or minerals). Many chemical additives are used and they are subject to regulation, since individuals may be affected by constant exposure even to traces of certain additives and may suffer side effects ranging from headaches and hyperactivity to cancer. Food companies in many countries are now required by law to list additives used in their products. Within the European Union, approved additives are given an official E number.
They must be listed on labels of foods sold in the US so consumers may be aware of those they cannot tolerate. The natural food movement has grown enormously in the 1970s and 1980s, as increasing awareness of the dangers of additives sent consumers looking for additive-free foods.
Artificial sweeteners are used in a range of products for diabetics and for weight loss or weight control.
Nutrients may be added to replace or enhance food value. Minerals and vitamins are the most common, especially where the diet would otherwise be deficient, leading to diseases such as beriberi and pellagra.
Preservatives are primarily antioxidants and antimicrobials that control natural oxidation and the action of microorganisms. They slow down the rate of spoliage by controlling the growth of bacteria and fungi. See food technology.
Emulsifiers and surfactants regulate the consistency of fats in prepared food and on the surface of the food in contact with the air. They modify the texture of food and prevent the ingredients of a mixture from separating out.
Thickeners, primarily vegetable gums, regulate the consistency of food. Pectin acts in this way on fruit products.
Leavening agents lighten the texture of baked goods without the use of yeasts. Sodium bicarbonate is an example.
Acidulants sharpen the taste of foods but may also perform a buffering function in the control of acidity.
Bleaching agents assist in the aging and whitening of flours.
Anticaking agents prevent powdered products coagulating into solid lumps.
Antioxidants prevent fatty foods from going rancid by inhibiting their natural oxidation.
Humectants control the humidity of the product by absorbing and retaining moisture.
Clarifying agents are used in fruit juices, vinegars, and other fermented liquids. Gelatin is the most common.
Firming agents restore the texture of vegetables that may be damaged during processing.
Foam regulators are used in beer to provide a controlled “head” on top of the poured product.
Something added to enhance food or gasoline or paint or medicine.

Singular of additives is additive.