Applications of natural plant extracts in soft drinks - Natural Food Additives, Ingredients and Flavourings - page 343

easier to disperse or dissolve the oleoresin in the oil phase of an emulsion than to
dissolve in a fl avouring solvent.
In the preparation of an emulsion for soft drink use, suitable oil (usually a
citrus oil or citrus terpenes) is combined with a suitable emulsifying agent.
So-called ester gums or wood rosin ester have been widely used for this, although
a more consistent product can often be prepared by the use of sucrose acetate
isobutyrate (SAIB).The aqueous phase will contain a hydrophilic emulsifying
agent such as gum Arabic. The phases are mixed well in appropriate proportions
using a high shear mixer and then subjected to emulsifi cation in a high pressure
emulsifi er at pressures of at least 100-150 bar. To obtain a stable emulsion,
particle sizes of below 10 μm should be achieved.

Aqueous or aqueous alcoholic extracts
A limited range of concentrated extracts for use in soft drinks may be prepared by
extraction of the plant material with water. Of these, a good example is kola nut
with the end product being widely used in the manufacture of cola drinks. Such
products are prepared by suspending or extracting the botanical material in water
(hot or cold as necessary) for an appropriate time, separating the extract and
evaporating water to give a material with a solids content of around 80% by
weight. Extracts produced in this way are vulnerable to the growth of moulds on
the surface, although by covering the surface with a thin layer of ethanol, the risk
of mould development may be effectively controlled for a limited time.
Concentrated aqueous extracts do not normally present any particular diffi culty
when being incorporated in end products.
Direct extracts are those prepared by soaking the botanical in water or in some
cases aqueous alcohol, separating the liquid after time and incorporating the
extract as a direct ingredient of required proportion in the end product. In many
instances, such techniques were used in the early manufacture of soft drinks (e.g.
ginger beer), but there are now soft drink manufacturers that are using these direct
extraction techniques to produce high value products. Products made by
incorporating direct extracts include ginger beer, dandelion and burdock, and
elderfl ower.
Direct extracts, particularly of fl owers such as elderfl ower, are also made by
soaking the botanical in sugar syrup. Extracts made in this way are generally more
effective in removing the aromatic components of the fl ower than simple water
extracts. There is likely to be a signifi cant loss of syrup retained on the botanical
material unless steps are taken to carry out a second soak with water and to use
this as the basis for the next batch of syrup. Even where this is carried out,
carbohydrate components of the extracting medium will contribute signifi cantly
to the cost of the end product.
Some extractions, such as ginger, require heat to be effective. The increased
interest in ginger as a culinary ingredient means that it is readily available as fresh
or dried material but, in the manufacture of ginger beer, it is normal to use dried
root as it is readily milled or kibbled to maximise the surface for extraction.
Prepared root is then subjected to extraction in hot water which, in addition to

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