n

any of various natural or synthetic substances, such as salt, monosodium glutamate, or citric acid, used in the commercial processing of food as preservatives, antioxidants, emulsifiers, etc, in order to preserve or add  flavor,  color, or texture to processed food.

Some additives have been used for centuries; for example, preserving food by pickling (with vinegar), salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines. With the advent of processed foods in the second half of the 20th century, many more additives have been introduced, of both natural and artificial origin. Many modern products, such as low-calorie, snack, and ready-to-eat convenience foods, would not be possible without food additives.

Categories

Under the Food Additives Amendment, two groups of ingredients were exempted from the regulation process.

GROUP I - Prior-sanctioned substances - are substances that FDA or USDA had determined safe for use in food prior to the 1958 amendment. Examples are sodium nitrite and potassium nitrite used to preserve luncheon meats.

GROUP II - GRAS (generally recognized as safe) ingredients - are those that are generally recognized by experts as safe, based on their extensive history of use in food before 1958 or based on published scientific evidence. Among the several hundred GRAS substances are salt, sugar, spices, vitamins and monosodium glutamate (MSG). Manufacturers may also request that FDA review the industry's determination of GRAS Status.

Otherwise food additives can be divided into several groups, although there is some overlap between them.

Acids  - Food acids are added to make flavors "sharper", and also act as preservatives and antioxidants. Common food acids include vinegar, citric acid, tartaric acid, malic acid, fumaric acid, and lactic acid.

Acidity regulators - Acidity regulators are used to change or otherwise control the acidity and alkalinity of foods.

Anticaking agents - Anticaking agents keep powders such as milk powder from caking or sticking.

Antifoaming agents - Antifoaming agents reduce or prevent foaming in foods.

Antioxidants - Antioxidants such as vitamin C act as preservatives by inhibiting the effects of oxygen on food, and can be beneficial to health.

Bulking agents - Bulking agents such as starch are additives that increase the bulk of a food without affecting its taste.

Food coloring - Colorings are added to food to replace colors lost during preparation, or to make food look more attractive.

Color retention agents - In contrast to colorings, color retention agents are used to preserve a food's existing color.

Emulsifiers - Emulsifiers allow water and oils to remain mixed together in an emulsion, as in mayonnaise, ice cream, and homogenized milk.

Flavors - Flavors are additives that give food a particular taste or smell, and may be derived from natural ingredients or created artificially.

Flavor enhancers - Flavor enhancers enhance a food's existing flavors. They may be extracted from natural sources (through distillation, solvent extraction, maceration, among other methods) or created artificially.

Flour treatment agents - Flour treatment agents are added to flour to improve its color or its use in baking.

Glazing agents - Glazing agents provide a shiny appearance or protective coating to foods.

Humectants - Humectants prevent foods from drying out.

Tracer gas - Tracer gas allow for package integrity testing to prevent foods from being exposed to atmosphere, thus guaranteeing shelf life.

Preservatives - Preservatives prevent or inhibit spoilage of food due to fungi, bacteria and other microorganisms.

Stabilizers - Stabilizers, thickeners and gelling agents, like agar or pectin (used in jam for example) give foods a firmer texture. While they are not true emulsifiers, they help to stabilize emulsions.

Sweeteners - Sweeteners are added to foods for flavoring. Sweeteners other than sugar are added to keep the food energy (calories) low, or because they have beneficial effects for diabetes mellitus and tooth decay and diarrhea.

Thickeners - Thickeners are substances which, when added to the mixture, increase its viscosity without substantially modifying its other properties.

SAFTEY

There has been significant controversy associated with the risks and benefits of food additives. Some artificial food additives have been linked with cancer, digestive problems, neurological conditions, ADHD, heart disease or obesity. Natural additives may be similarly harmful or be the cause of allergic reactions in certain individuals. For example, safrole was used to flavor root beer until it was shown to be carcinogenic. Due to the application of the Delaney clause, it may not be added to foods, even though it occurs naturally in sassafras and sweet basil.

Still, we consumers have concerns about additives because we may see the long, unfamiliar names and think of them as complex chemical compounds. In fact, every food we eat - whether a just-picked strawberry or a homemade cookie - is made up of chemical compounds that determine flavor, color, texture and nutrient value. All food additives are carefully regulated by federal authorities and various international organizations to ensure that foods are safe to eat and are accurately labeled.

The FDA provides a helpful background informational brochure  about food and color additives: what they are, why they are used in foods and how they are regulated for safe use. 

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Sources:
"Food additive." © Encyclopedia Britannica, Inc.. Encyclopedia Britannica, Inc.. 24 Oct. 2011.