Natural food and beverage colourings - Natural Food Additives, Ingredients and Flavourings - page 36

2.2.9 Carminic acid/carmine
Carmine or cochineal is a well-established crimson pigment extracted from insects
in South America. 15 The insect source has connotations for the fi nal food as it
cannot be claimed to be vegetarian, kosher or halal. The specifi c insect Dactylopus
coccus costa is found on varieties of cactus (Opuntia or Nopalea) found mainly in
Peru, Bolivia and Chile. Insects are either picked from the wild or harvested from
managed plantations. The pigment is extracted from the bodies of female insects,
which contain up to 25% of their dry weight as the colour. The harvested insects
are killed by being immersed in hot water and then dried either in the sun or in an
oven until they are approximately 30% of their original weight. In this state they
can be stored until required for extraction.
The South American cochineal extraction companies quote statistics of fi ve
million insects required to make 32 lbs of extract. The extraction is carried out
using hot water with added ammonia or bicarbonate to make it alkaline. The
initial extract is carminic acid and this is a water-soluble pigment that has a
shade dependant on the pH of the application. At pH 4 and below it is a clear
orange colour; as pH increases it becomes redder and bluer until it is purple-red
above pH 6.5.
Recent developments have meant that redder carminic acid formulations are
now available that can give a shade similar to carmine but without the need for
further chemical processing into carmine. Commercially more signifi cant is the
derivative of carminic acid, carmine, which is an aluminium lake. Within the
European Union the lakes of pigments legislation carry the same E numbers and
are allowed within the same applications and at the same dosages. 1 It is not
therefore possible from the fi nal packaging to determine if a lake colour has been
used.
Carmine is formed by precipitating carminic acid onto an alumina hydrate
substrate and dried to typically 50% as carminic acid. Carmine is insoluble in
water but can be rendered water soluble by reaction with strong alkali. The
resulting solution gives a crystal clear burgundy red colour with excellent stability
to heat, light and oxidation. Indeed carmine is one of the most stable of all natural
colours and in some applications more stable than some synthetic colours.
Carminic acid is typically sold as a 5% product either as a liquid or powder,
and increasingly in redder shades. The most prevalent carmine formulations sold
are a 4.5-5% water-soluble liquid and a 50% insoluble powder. By manipulating
the laking process and the particle size of the powder it is possible to adjust the
shade and the tinctorial strength.
Key applications for carmine are confectionary, meat-based products, fruit
preparations, sausage casings, sauces, marinades and surimi. In applications such
as surimi where a thin layer of colour is applied to the top surface of the fi sh/crab
stick, it is vital that no migration of the colour into the white under-layer occurs.
By using the insoluble carmine powder this is achieved because the movement of
water between the two layers does not cause movement of the insoluble powder.
Carmine is under increasing pressure because of its insect source and reports
of allergenic reactions to foods coloured with carmine. As a pigment its stability

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