Extraction tests were carried out in a high pressure apparatus
supplied by Thar Technology. A schematic diagram of the equipment used in this work is shown in Fig. 1. This set-up included an extraction vessel(capacity of 100 mL)
with a thermostatic jacket to control the extraction temperature,
two pumps with a maximum flow rate of 50 g/min (one for carbon
dioxide and the other for co-solvent), a back pressure valve
regulator to control the system pressure, and a cyclonic separator
to allow periodic discharge of the extracted material during the
extraction process. For all tests the extraction vessel was loaded
with approximately 15 g of sample. Extracts were recovered in a
cyclonic separator and then collected in glass bottles and stored
in the extraction solvent in darkness at −20 ◦C prior to assay.
The global yield (X0) for all extraction method was calculated considering
the ratio between mass of extract and mass of dry raw material.
Apreliminary study was conducted in order to improve the yield
and antioxidant activity of the extracts obtained using CO2 and CO2
plus co-solvents. The effects of different variables on the extraction
process were analyzed by considering the following operating
conditions: pressures of 10 and 40 MPa, temperatures of 35 and
55 ◦C, co-solvent percentages of 0 and 20% and type of co-solvent,
methanol and ethanol. All tests were carried out with a CO2 flow
rate of 20 g/min and an extraction time of 3 h.
Results were compared with SWE. This technique is lessdependent
on pressure and highly dependent on temperature [19,20].
However, it is important to consider that the temperatures above
100 ◦Ccouldgenerateunwantedoxidativeprocesses [22],thus SWE
tests were carried out at 100 ◦C, 4 MPa, a flow rate of 10 g/min and
3 h.
For this preliminary study mango leaves of the variety Osteen
were used as raw material so it is the variety widely cultivated in
the region of Málaga, Spain.