Tecnologia De Extraccion Por Fluidos Supercriticos

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The Use of Supercritical Fluid Extraction Technology in Food Processing
R.S. Mohamed and G.A. Mansoori
Featured Article - Food Technology Magazine, June 2002
The World Markets Research Centre, London, UK

The Use of
Supercritical Fluid
Extraction Technology
in
Food Processing
By

Rahoma S. Mohameda and G.Ali Mansoorib,*
a

School of Chemical Engineering, The State University ofCampinas-Unicamp, C.P. 6066,
Campinas-SP, 13083-970, Brazil
b

Chemical Engineering Department, The University of Illinois-Chicago, 810 S. Clinton
Street, Chicago, IL 60607-7000 USA
(*) The corresponding Author e-mail:

Unfortunately Professor Rahoma S. Mohamed passed away on Friday, April 23 2004 after a long illness

The Use of Supercritical Fluid Extraction Technology in FoodProcessing
R.S. Mohamed and G.A. Mansoori
Featured Article - Food Technology Magazine, June 2002
The World Markets Research Centre, London, UK

There is an increasing public awareness of the health, environment and safety
hazards associated with the use of organic solvents in food processing and the possible
solvent contamination of the final products. The high cost of organic solvents and theincreasingly stringent environmental regulations together with the new requirements of the
medical and food industries for ultra-pure and high added value products have pointed out
the need for the development of new and clean technologies for the processing of food
products. Supercritical fluid extraction using carbon dioxide as a solvent has provided an
excellent alternative to the use ofchemical solvents. Over the past three decades,
supercritical CO2 has been used for the extraction and isolation of valuable compounds
from natural products (Mansoori et al 1988, Martinelli et al 1991, del Valle and Aguilera
1999, Hartono et al 2001).
Supercritical CO2 was found to be selective in the separation of desired compounds
without leaving toxic residues in extracts and without the risk ofthermal degradation of
processed products. Through the exploitation of the solvating power acquired by fluids near
their critical points and the sensitivity of this power to small perturbations in temperature,
pressure and modification of the solvent with the addition of entrainers, solvent-free
extracts were readily obtained due principally to the high volatility of these solvents atambient conditions. The favorable transport properties of fluids near their critical points
also allows deeper penetration into solid plant matrix and more efficient and faster
extraction than with conventional organic solvents.
For the past three decades, the commercial application of supercritical fluid
technology remained restricted to few products due to high investment costs and for being
newand unfamiliar operation. With advances in process, equipment and product design
and realization of the potentially profitable opportunities in the production of high added
value products, industries are becoming more and more interested in supercritical fluid
technology (Sihvonen, et al., 1999). The extraction is carried out in high-pressure
equipment in batch (Figure 1) or continuous manner(Figure 2). In both cases, the
supercritical solvent is put in contact with the material from which a desirable product is to
be separated. The supercritical solvent, now saturated with the extracted product, is
expanded to atmospheric conditions and the solubilized product is recovered in the
separation vessel permiting the recycle of the supercritical solvent for further use.
Table 1presents some of the existing commercial applications put in operation over
the past few years. Supercritical fluid technology is now recognized as an effective
analytical technique with favorable and comparable efficiencies to existing chemical
analysis methods and when applied for the qualitative and quantitative identification of
constituents of naturally occurring products and heat-labile...
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