In addition

As consumers demand convenient,readily available,tasty,nutritious and reasonably-priced foods,additives come in handy. A food additive is any substance or mixture of substances other than the basic components of a food. It becomes part of the food as a result of production,processing,packaging or storage. Common food additives,their uses and benefits include:
Preservatives such as sodium benzoate in sauces or fruit juices prevent the growth of germs and moulds.
Antioxidants such as ascorbic acid (vitamin C) in butter,BHA (Butylated Hydroxyanisole) or BHT (Butylated Hydroxytoluene) in oils stop fats from going rancid.
Emulsifiers and stabilisers such as calcium alginate in ice cream impart smooth texture,uniformity and body to foods.
Colours,whether natural or synthetic,dont add to nutritional value,but make food colourful and appealing.
Flavour enhancers such as monosodium glutamate (MSG) bring out the flavour in food.
Anti-caking agents such as calcium silicate,ammonium citrate,magnesium stearate and silicon dioxide prevent lumping in table salt,baking powder,powdered sugar and other powdered products.
Nitrates and related form,nitrites,used with salt to preserve meat,prevent microbial growth. Sodium and potassium nitrates and nitrites are used to preserve meats such as bacon,ham,salami,hot dogs and give bright pink colour to meats.

Consumers have been led to believe that food additives are harmful. But most additives go through rigorous testing for possible toxic effects before being permitted into the food chain. In 1958,all food additives used in the US and considered safe at that time were put on a generally recognized as safe (GRAS) list. Manufacturers were allowed to continue to use these food additives,without special clearance,when needed in food products. As is still the case,FDA bears responsibility for proving they are not safe and can remove unsafe products from the list.
The FDA regulates the type of food an additive can be used in,the maximum quantity that can be used and the information that must appear on the label. The maximum quantity is set at 0.01 of the level at which there was no adverse effect in test animals; thus there is at least a 100 fold margin of safety.

However,a few susceptible people react adversely to additives such as tartrazine,benzoic acid,MSG and sulfites. Such sensitivities occur in one in 1,800 people worldwide. In such cases,individuals with some form of allergy like asthma,hay fever,urticaria etc. can be affected by these substances. Reaction depends on the type of preservative or additive ingested. The reaction may occur immediately or be delayed for 6 to 24 hours. u