Wednesday, April 27, 2011

FOOD ADDITIVES

Food additives are substances added to food to preserve their freshness, improve their visual appeal or taste, enhance their flavor etc. Humans have been using food additives since long time. For example, preserving food by adding vinegar, oil, sugar and salt. Since more number of food additives, both artificial and natural ones, have been introduced with the advent of processed food, it is important to know the type of chemicals used as food additives.

There are various types of food additives used with different purposes. Some of them are :-

Food AcidsAdded in order to add tartness to the flavor of foods, also act as anti-oxidants and preservatives. Example:- citric acid, lactic acid, fumaric acid, malic acid, tartaric acid, phosphoric acid (in colas), and vinegar. 
Food coloring: Colorings are added to food to replace colors lost during preparation, or to make food look more attractive. Example:- Caramel coloring (E150), made from caramelized sugar. The great bulk of artificial colorings used in food are synthetic dyes.
Flavors: These are added in order to enhance the flavors of foods, which can be either artificial or made from natural sources. Some of the common flavoring agents are monosodium glutamate (MSG), maltol, and disodium guanylate. Some of the compounds used to produce artificial flavors are;
Chemical Odor
Ethylvanillin Vanilla
Isoamyl acetate Banana
Benzaldehyde Bitter almond
Cinnamic aldehyde Cinnamon
Ethyl propionate Fruity
Methyl anthranilate Grape
Limonene Orange

Preservatives: These are chemicals that are added to food products in order to prevent food from spoiling due to the growth of micro-organisms like bacteria and fungi. Apart from being anti-microbial, there are also preservatives that are anti-oxidants. Common antimicrobial preservatives include calcium propionate, sodium nitrate, sodium nitrite, sulfites (sulfur dioxide, sodium bisulfite, potassium hydrogen sulfite, etc.) and disodium EDTA. Antioxidants include BHA and BHT. 

Sodium nitrite and sodium nitrate are two closely related chemicals used for centuries to preserve meat. Nitrate is harmless but, it is readily converted to nitrite where it can form nitrosamines, extremely powerful cancer-causing chemicals. The chemical reaction occurs most readily at the high temperatures of frying. Nitrite has long been suspected as being a cause of stomach cancer. 
Antioxidants: Antioxidants such as vitamin C act as preservatives by inhibiting the effects of oxygen on food or preventing them from becoming rancid, and can be beneficial to health.
 
Stabilizers: Stabilizers, thickeners and gelling agents, like agar or pectin (used in jam) give foods a firmer texture.
Emulsifiers: These are added in order to enable oils and water to emulsify, or remain combined together, such as homogenized milk, mayonnaise, and ice-cream. Examples of food emulsifiers are egg yolk where the main emulsifying agent is lecithin, honey, and mustard, where a variety of chemicals in the mucilage surrounding the seed hull act as emulsifiers.

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.To regulate these additives, and inform consumers, each additive is assigned a unique number, termed as "E numbers", which is used in Europe for all approved additives.