Natural food and beverage colourings - Natural Food Additives, Ingredients and Flavourings - page 33

Caramel colours can have an ionic or colloidal charge which may be positive,
negative or neutral although the majority of caramel commercially available has a
negative colloidal charge. However, there are specifi c applications where a
positive colloidal charge is required such as beer where some residual malt
proteins which are positively charged; unless a caramel with a positive charge is
also used, precipitation will occur leading to hazing of the beer.
Caramels have inherent emulsifi cation characteristics, which can help stabilise
products such as beverages where fl avour oils could have a tendency to rise to the
surface and ring.

2.2.7 Carotene, paprika and lutein
Carotene, paprika and lutein are chemically related and are termed carotenoids.
These are a range of approximately 600 pigments widely distributed in nature and
give a spectrum of orange to yellow colours. 14 Although extracted from different
sources, their properties, methods of application and required formulation
technologies are similar and it makes sense to treat them together in this chapter.
Carotene is available as a mixture of carotene isomers, predominantly β and α ,
from palm oil where it is removed as one of the fi nal stages of palm oil manufacture
as a decolourisation step. Extracts of mostly β -carotene are available from either
halo-tolerant algal ( Dunaliella salina ) or fungal ( Blakeslea trispora ) sources. In
both cases the extracts contain over 95% β -carotene. These natural sources are
available at typically 20-30% carotene suspended in a vegetable oil. Nature
identical β -carotene, which is produced from base petrochemicals to be chemically
identical to that found in nature, is also available in a high purity crystalline form.
The shades of these oil-based extracts are very similar and the choice is often
determined by economics, but although all the sources above are permitted as
colours in Europe, current US legislation requires the β -carotene level to be over
95% which prevents the use of mixed carotenes as colours. Many carotenoids
have pro-vitamin A activity, which means they can be converted into vitamin A
once ingested. The conversion factors for each vary but β -carotene is most
effectively converted into retinol or vitamin A.
Paprika is extracted from the sweet red pepper, Capsicum annum L., which is
typically grown in India. As with carotene, paprika is initially produced as an oil-
based product termed an oleoresin. Paprika oleoresin contains a number of
pigments with the most important being the red pigment capsorubin. The spice
molecule capsanthin co-extracts with capsorubin which, unless its level is
controlled, it can lead to a fl avour carryover in the fi nal application. Under
EU legislation, 3 the paprika extract must be not less than 7% as carotenoids of
which at least 30% must be capsanthin/capsorubin. Additionally, to distinguish it
from materials for use as spices or fl avours, the capsanthin level must be below
250 ppm.
Lutein from Tagetes erecta L. is a purifi ed extract obtained from marigold
oleoresin, which is extracted from the petals of marigold fl owers with organic
solvents. The lutein pigment is co-extracted with other related carotenoids and

￿ ￿ ￿ ￿ ￿