Natural food and beverage colourings - Natural Food Additives, Ingredients and Flavourings - page 35

The presence of low levels of pro-oxidant metals can also have an infl uence.
Examples exist of standard beverage recipes being transferred between bottling
plants suffering from a dramatic loss of colour caused by a change in water supply
and the associated levels of pro-oxidant metals such as copper, iron and manganese.
These problems can be solved by a combination of additional anti-oxidants such
as ascorbic acid and the inclusion of a metal-sequestering agent such as
ethylenediaminetetraacetic acid (EDTA) or citric acid.
Formulation issues such as emulsion breakdown can lead to release of oily
carotenoid deposits into a food system most classically seen as a β -carotene neck-
ring in a beverage. Such problems are normally solved by understanding whether
it is a processing issue or an ingredient interaction that has caused the problem
and taking the appropriate action such as changing the order of addition of
ingredients or not pre-mixing the carotenoid colour in its concentrated form with
other ingredients such as the fl avour system.

2.2.8 Lycopene
Lycopene is also a carotenoid, but the nature of the formulations required to
deliver the optimum colour shade dictates a separate entry in this chapter.
Lycopene is the pigment responsible for the red colour in tomatoes and it increases
as the fruit ripens. Synthetic and fungal derived products are also available but at
the time of writing only that from tomatoes is permitted for use as a food colour.
Commercial lycopene production from tomatoes starts from strains of tomatoes
bred to deliver increased levels of lycopene. After solvent extraction, lycopene
crystals are milled to a specifi c particle size to deliver optimum colour expression
and stability. Unlike other carotenoids discussed earlier the preservation of the
lycopene crystals is essential to maintain a red colour. In the oil-soluble form,
lycopene gives an orange yellow colour not unlike paprika. Typical formulation
types are crystalline suspensions in glycerol or dried preparations on a water-
soluble carrier. In food applications this can be an issue if fat is present and
problems of retaining the red shade can occur at levels of fat at over 8%. The exact
level is dependent on the degree of saturation of the fats and heat applied. For
specifi c applications more oil-resistant formulations exist which increase the
tolerance to up to 15% fat.
The crystalline nature of the red lycopene colour gives a non-migrating
character such that in multi-layer applications such as surimi, desserts and cake
decorations the red colouration does not bleed into adjacent layers. The heat and
light stability is generally as for the other carotenoids with the associated
enhancement with the inclusion of ascorbic acid. As with the other carotenoids pH
does not infl uence the shade of lycopene, allowing its use in products such as milk
drinks made up from acidic syrups where a red colour is required in both acidic
and neutral pH products.
Key commercial applications for lycopene are surimi, beverages, fruit
preparations, meat analogues, decorations and coatings, panned confectionary
and milk drinks.

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