Dyes are certified, water soluble synthetic food
colorants. They are manufactured as powders, granules and liquids. The
synthetic dyes are of several types as per their basic compound and
structure.
The Anionic dyes have a sulphonic or carboxilic group . the Catonic dyes
have amino or aminomethyl as the basic group and are available as acid
salts. Azo dyes have 1 to 3 azo bonds and make the largest permitted food
dye. They have a primary aromatic amine and an aromatic compound and their
combinations cover a wide range of colors.
These dyes absorb light and reflect certain wavelength that is perceived as
its color. Dyes have to be certified for their safety to be used as a food
or cosmetic colorant. A dye which is listed as "FD&C" is
permitted by the Food & Drug Administration to be added to foods, drugs
and cosmetics. "D&C" means the dye may be used only in drugs
and cosmetics.
