Agriculture Reference
In-Depth Information
•
Process effi ciency
•
Unique routes to natural molecules
•
Sustainability.
In offering solutions that can address these drivers, the guiding principles of green
chemistry proposed by Anastas (1998) and more recently Tang (2008) have been
used to develop alternative approaches both to the extraction of natural fl avour
preparations and synthesis of fl avour molecules.
PRODUCTIVELY - The Principles of Green Chemistry (Tang 2008)
P -
Prevent waste
R -
Renewable materials
O -
Omit derivatisation steps
D -
Degradable chemical products
U -
Use safe synthetic methods
C -
Catalytic reagents
T -
Temperature, pressure ambient
I -
In process monitoring
V -
Very few auxiliary substances
E -
E-factor, maximise feed in product
L -
Low toxicity of chemical products
Y -
Yes it's safe
12.2 Green extraction techniques
A wide range of natural fl avour preparations are already available including:
•
Essential oils, herb and spice extracts
•
Flavour molecules fractionated from essential oils or botanical extracts
•
Natural fl avour molecules produced by fermentation.
The technologies used to produce these traditional products are well-established
but use methods that are often energy-intensive or solvents that are produced from
fossil fuels and need to be tightly controlled with respect to residual levels.
The largest volume of extracts used for food fl avouring is herb and spice
oleoresins. These are mostly extracted at source using a range of organic solvents
such as hexane and acetone. In the European Union (EU), Directive 2009/32/EC
(EC 2009) and Directive 2010/59/EU (EC 2010) defi ne both permitted extraction
solvents for fl avouring preparations and their maximum residue levels in foodstuff.
Additional restrictions are prescribed by the organic certifi cation bodies (for example,
the Soil Association in the UK; Soil Association, 2011), although these vary
considerably between countries as there is no harmonised defi nition of 'organic'. A
summary of the current permitted solvents for the preparation of fl avouring
substances in the EU is shown in Table 12.1. In applying the principles of green
chemistry, water, carbon dioxide and ethanol clearly represent both safer solvents
and the use of a renewable feedstock as well as having the widest acceptability.
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