Agriculture Reference
In-Depth Information
Table 15.3
Types of BP and BPC extracts
Type of extract
Description
Liquid extract
An extract, usually aqueous or aqueous/alcoholic, prepared by liquid
extraction of a botanical and subsequent concentration such that the
amount of active material in 1 kg of extract is approximately
equivalent to 1 kg of botanical.
Tincture
An extract prepared by liquid extraction of botanical, usually with
alcohol, such that 1 kg of botanical produces 10 litres of extract
without any concentration. Tinctures are also produced by diluting
liquid extracts by a factor of ten.
Soft extract
An extract prepared by further concentration of a liquid extract such
that the level of solids reaches about 70-80% by weight.
Dry extract
An extract prepared by drying a soft extract to reduce the moisture
level to around 5-10% by weight.
Most plant extracts of whatever type are used in the preparation of fl avours and
compounds that are employed in the manufacture of soft drinks rather than directly
in the manufacture of the beverage itself. However, reference was made above to
the increasing quantities of beverages made by traditional methods that involve
the infusion of botanical raw material and direct use of that infusion as a signifi cant
component of the end product.
Extracts that are most widely used as components of fl avourings are oleoresins
(e.g. ginger) and soft extracts such as kola nut extract.
15.4.1
Manufacture of solvent extracts
Selection and preparation of raw material
Although the extracts used in fl avouring components of soft drinks are employed
in very small amounts, the fl avouring characteristic added to the end product is
often a critical component of the overall taste or aroma of the drink and, for that
reason, selection of raw material of appropriate quality is essential.
Selection may depend on the level of a specifi c component in the raw material
such as the level of capsaicin in capsicums or it may require the raw material to be
sourced from a particular location. As an example, vanilla beans employed to make
vanilla extracts and used in cola drinks show signifi cantly different taste and aroma
qualities when grown in different geographical locations. In addition to the
organoleptic qualities, botanical materials are mostly supplied 'dry' which in practice
means a moisture level of below 10% and preferably 5%. Higher moisture levels
carry a signifi cant risk of mould growth and, in extreme circumstances, spontaneous
combustion. Since geographical locations for some raw materials are remote in less
developed countries, harvesting methods may increase the risk of debris of various
types being included with the botanical. It is desirable to ensure that metal and other
obvious gross contamination is removed before processing begins.
Another risk area that is increasingly important in the overall quality assurance
process is that of contamination by pesticides and herbicides. It is usual to screen
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