Optimization of the supercritical fluid extraction of Quercus cerris cork towards extraction yield and selectivity to friedelin

authors	de Melo, MMR; Vieira, PG; Sen, A; Pereira, H; Portugal, I; Silva, CM
nationality	International
journal	SEPARATION AND PURIFICATION TECHNOLOGY
author keywords	Cork; Design of experiments; Friedelin; Quercus cerris; Selectivity
keywords	AZIMA-TETRACANTHA LAM.; FUTURE PERSPECTIVES; DESIGN; GREEN; OIL
abstract	Optimization of the supercritical fluid extraction of Quercus cerris cork was carried out using Box-Behnken design of experiments and response surface methodology (RSM). The optimized process variables were temperature (T: 40, 50 and 60 degrees C), ethanol content (EtOH: 0.0, 2.5 and 5.0 wt%) and CO2 flow rate (Q(CO2): 5, 8 and 11 g min(-1)). The studied responses were total extraction yield (eta(Total)), friedelin concentration of the extract (C-Friedelin), and selectivity towards friedelin (alpha(F,nF)). The linear effect of EtOH was by far the most influent operating condition (Pareto analysis) and the highest yield (eta(Total) = 2.2 wt%) was attained with 5.0 wt% EtOH. The RSM model estimates maximum friedelin concentration in the extracts (38.2 wt%) to occur without cosolvent (0 wt% EtOH) for the lowest T (40 degrees C) and Q(CO2) (5 g(CO2) min(-1)). As for selectivity, the experimental alpha(F,nF) values were always higher than 1.0 and reached 3.1 (at 50 degrees C, 5 wt% EtOH, 11 g(CO2) min(-1)). Altogether, these results suggest friedelin can be selectively removed from Quercus cerris cork by supercritical fluid extraction within the range of experimental conditions studied.
publisher	ELSEVIER
issn	1383-5866
isbn	1873-3794
year published	2020
volume	238
digital object identifier (doi)	10.1016/j.seppur.2019.116395
web of science category	Engineering, Chemical
subject category	Engineering
unique article identifier	WOS:000513984900015