Natural food and beverage colourings - Natural Food Additives, Ingredients and Flavourings - page 32

in specialised products such as Sage Derby cheese. In order to make a more lime
shade, blends with curcumin are used and these are most commonly seen in
confectionary products. In beverages a combination of copper chlorophyllin and
a clear carotene emulsion has proved an effective replacement for the combination
of the synthetic colours Green S and Quinoline Yellow found in lime-fl avoured
drinks. If the fi nal application where the pH is below 4 (such as beverages), an
acid-stable form of copper chlorophyllin should be used to prevent precipitation
of the pigment. Care should also be taken in processes where a pre-mix is made
that has greater acidity than the fi nal product, as an initial acid shock could lead to
precipitation later during shelf life.
A drawback of the formulations designed to give copper chlorophyllin
enhanced acid stability is that they can take longer to disperse and have a greater
tendency to foam in high speed fi lling operations. The stability of copper
chlorophyllin coloured products can be enhanced by including 200-400 parts per
million (ppm) ascorbic acid as an anti-oxidant.

2.2.6 Caramel
Caramel is the most widely used of all natural colours and it is estimated that 80%
of colour added to food and drink is caramel based. 12 Depending on type and
dosage shades from yellow to deep brown can be achieved.
Caramelisation is a natural process that occurs in the cooking of foods as
carbohydrates react in the presence of heat. The sugars initially undergo a dehydration
reaction and then a series of condensation reactions as part of a polymerisation
process. The fi nal colour that is produced is a mixture of different complex molecules
of different molecular weight. Industrial production of caramel uses a much more
controlled process with glucose, fructose or sucrose as the starting material,
controlled heating profi les and the addition of approved catalysts as appropriate.
There are four types of caramel known as E150a, E150b, E150c and E150d in
Europe and similarly Caramel Colors I, II, III and IV in America. 3,13 E150a, also
known as plain caramel, is created with no catalysts and is the lightest of the
caramel colours. E150b, also known as caustic sulphite caramel, is darkened by
use of a sulphite compound, E150c with an ammonium catalyst and E150d
by ammonium and sulphite. Consequently E150d is the darkest of all the caramels.
It is important to remember that the caramels used for colouring are different to
those used for fl avouring foods.
As has been stated earlier there is no legal defi nition of a natural colour, but with
caramels, the general convention is that E150a is seen as being a natural colour
whereas E150b, E150c and E150d are referred to as being derived from a natural
source.
All caramels are available in powder and liquid forms and are truly water-
soluble to give a clear colour in application. They have excellent stability to pH,
heat, light and oxidation making them suitable for a wide range of applications.
Key applications for the caramel colours are soft drinks such as ginger beer and
cola, beers and spirits, sauces and confectionary.

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