Food Colours

 

FOOD COLOURS

These include colour stabilizers, colour fixatives, colour retention
agents etc. They consist of synthetic colours. Even though colours add
nothing to the nutritive value of foods, without certain colours most
consumers may not accept certain foods. Thus colours are frequently
added to restore the natural ones lost in food processing or to give the
preparations the natural colour we expect.

Originally many colour additives were natural pigments or dyes. For
example, spinach juice or grass, marigold flower, and cochineal were
used to obtain green, yellow and red colour respectively. This gave
place to synthetic dyes obtained from coaltar. Synthetic colours
generally excel in colouring power, colour uniformity, colour stability
and cost. Further, in many cases, natural colouring materials do not
exist for a desired hue. Carbonated beverages, gelatin dessert, candies
and bakery goods are some foods that are coloured with coaltar dyes.
As number of coaltar compounds have been shown to be 

potentcarcinogens, the use of coaltar dyes as food additives is restricted.

Many countries have restricted the number of coaltar dyes for use in
foods while some other countries have completely banned their use.
Food colours also include some inorganic materials, such as iron oxide
to give redness, and titanium dioxide to intensify whiteness.
A number of natural food colours extracted from seeds, flower,
insects and foods are also used as food additives. One of the best
known & most widespread red pigments is bixin, derived from the
seed coat of Bixin orellana, the lipstick pod plant of south American
origin. Bixin is not considered to be carcinogenic. The major use of
this plant on a worldwide basis, however, is for the annatto dye, a
yellow to red colouring material extracted from the orange red pulp of
the seeds. Annatto has been used as colouring matter in butter,
cheese, margarine and other foods. Another yellow both flavouring
and colouring properties and has been used for colouring foods.
Turmeric is a spice that gives the characteristic colour of curries and
some meat products and salad dressings. A natural red colour,
cochineal obtained by extraction from the female insect Coccus cacti,
grape skin extract, and caramel, the brown colour obtained from burnt
sugar are some natural colours that are used as food additives.

Colours are used for following reasons:

1. Restore original appearance of the food which is lost during heat
processing or storage.

2. Uniformity of colour as a result of natural variations.

3. To intensify colour as a result of natural variations.
4. To protect light-sensitive vitamins.
5. To impart attractive appearance to foods.
6. To preserve the identity by which foods are recognized.
7. To serve as visual indication of foods quality.sSafety Evaluation:

Safty Evaluation:

1. Prior to 1900, there was no regulation in the US on usage of
food colours in processed foods.

2. With time colours proved to be toxic and their overuse often
resulted in food poisoning.

3. National Academy of Science (NAS) cited certain cases leading
to food poisoning due to HgS(vermilion) and Red lead (Pb 3 O 4 )
, copper arsenite and Lead chromate.

4. In the 20 th century, food colours were under rigorous scrutiny
for their technical suitability and toxicological properties.

5. U.S. Congress recognized the proliferation of colour additive
usage as a threat to public health.

6. Then synthetic colours also known as Aniline dyes were
manufactured from coal tar derivatives (from byproducts of
petroleum industry).

7. USDA undertook the study of chemical and physiological
    properties of 100 coaltar dyes.
    F & D Act of 1906: Listed seven dyes for use in foods.
    a. Amaranth
    b. Erythrosine
    c. Light green SF
    d. Orange I
    e. Ponceau 3R
    f. Indigosine
    g. Napthoyellow.

8. In 1938 Federal Food, Drug & Cosmetic Act which superceded
   the act of 1906, established mandatory certification. This act
   created three new categories of synthetic coaltar dyes.

 I.D&C colours: Dyes and pigments considered safe in drugs
  and cosmetics when in contact with mucous membrane
  when ingested.
 II. External D&C colours: Colours because of their oral toxicity
 were not certifiable for use in products intended for
ingestion but safe for external use.
 III. FD&C colours: Those certifiable for use in coloring foods,
drugs and colors.

9. Colour Additives Amendment Act of 1960 defines a colour
additive as any dye or pigment made or obtained from a
vegetable or animal or mineral capable of colouring a food,
drug or cosmetics or any part of the human body.

10 . The law consists of two parts.

 I part: Delaney clause: To prohibit addition of any colourant
            which is carcinogenic.

II part: Use of existing colours based on provisional listing
             pending competition of scientific investigation.

11 . After 1982, to add any new colours to this list, the FDA
       requires results from toxicological studies.
      a. One sub chronic feeding (90 day) in a non-rodent species.
      b. Acute toxicity studies in rats.
      c. Chronic feeding studies in atleast 2 species Eg: rats &
          mice (For 24-30 months)
      d. One teratology study
      e. One multigeneration reproduction.
      f. One mutagenicity test.

12 .U.K. monitors food colours on the basis of a colour Index
 system. Certified colours are available as water soluble dyes
or Insoluble dispersions lakes.13 . Except for lake FD & C Red 

No.40 all lakes are provisionally
listed by FDA.

14 . The soluble dyes readily dissolve in water and in certain
polyhydric solvents such as propylene glycols.

15 . FD&C dyes must contain a minimum of 85% pure dye, but
commercially 90-93% pure dye content is seen.

16 . If the sample complies with the specification, its certified &
that batch is released for use.

17 . The certification process ensures that every batch is
chemically identical to the pigment used in animal feeding on
which the approval is based.