Explain the utility of SCFE in pure extraction of flavours and fragrances
It is the prized aroma and taste that flavours and fragrances provide that makes them a huge global industry. Quite clearly, the method used for the extraction of flavors and fragrances matters. Because only a method that preserves the original aroma and taste will be useful.
Supercritical fluid extraction (SCFE) or supercritical extraction, as it is also called, is among the preferred methods for the extraction of flavors and fragrances. Its action is based on pressure differential – separating the required compound (called target molecule) at high pressure and throwing it out of solution at lower pressure.
Such action means the flavour or fragrance molecule is separated in its relatively pure form – only pristine molecules deliver all their touted benefits. And when carbon dioxide (CO2) is used as the fluid in the SCFE process, the process temperature remains low thereby avoiding thermal distortion.
Flavours typically find application in the Beverages, Bakery, Confectionary, Dairy, and Convenience Food industries. Fragrances are used by the Cosmetics, Toiletries, Soaps, Detergents, and Fine Fragrances sectors.
Over 250 species of plants serve as the source for more than 500 raw materials in the flavour and fragrance industry. Some of the most in-demand elements in the flavours and fragrances industry include the following:
Rose Oil
Tuberose Absolute
Angelica Root Oil
Jasmine Absolute
Ambrette Seed Oil
Orange Flavour Oil
Methods used for the extraction of flavours and fragrances include:
Supercritical Fluid Extraction
Solvent Extraction
Distillation
Mechanical Separation
Solvent extraction uses a solvent to first dissolve the target molecule and then separate it out from the solvent. The separation is, however, not complete and some solvent residues continue to linger in the target molecule. This reduces the purity of the extract.
Hydrodistillation uses heat to separate different fractions, each of which separate out at different temperatures. The process first dissolves the raw material in water and then boils the solution. Different molecules get separated at different temperatures.
SCFE uses a supercritical fluid (SCF) i.e. one that is at a:
Pressure above its critical pressure; and
Temperature above its critical temperature.
The ability of the SCF to dissolve target molecules can be fine tuned by changing its pressure. At one particular pressure, the SCF can extract one particular molecule while not extracting most of other compounds (the non target molecules). Some non-target molecules do get associated with the target molecules, but such association is minimal.
With a critical temperature of 31.1 deg-Celsius, carbon dioxide makes an excellent SCF. Process temperature of supercritical extraction which uses CO2 as the SCF is around this critical temperature – which is not very high. This avoids the thermal distortion issue – change in chemical composition at high temperatures – which is associated with distillation. Some solvent extraction processes also employ heat, further escalating the risk of change in composition.
Asia Pacific is expected to continue with its position as the number one market region for the flavour and fragrance market. Climbing incomes and rapid urbanization are the factors propelling the growth of the industry in this region. Over the world, the rising consumption of flavoured drinks is hiking the demand for flavours and fragrances.
