Supercritical Carbon Dioxide Extraction of Bioactive Compounds from Feijoa (Feijoa sellowiana) Leaves

Supercritical fluid extraction (SFE) technique has been studied for extraction of bioactive compounds from Feijoa sellowiana leaves. Results were compared with those obtained from conventional ethanolic extraction (CE). The best supercritical carbon dioxide (SC-CO2) extraction conditions was determined as 250 bar of pressure, 50 °C of temperature, and 90 min dynamic extraction time. Under these conditions, the crude extraction yield (CEY) of bioactive compounds was 38.14 ± 0.17 mg g-1. Spectrophotometric analysis revealed that the extract possesses strong radical scavenging activity (78.18 ± 0.12%, 74.19 ± 0.14%, 49.38 ± 0.18% inhibition of DPPH˙, ABTS˙, and OH˙, respectively). The HPLC analysis revealed that gallic acid, catechin, rutin, ferulic acid, apigenin, and quercetin are the major phenolic compounds present in the extract. The CEY obtained using the best conditions of SCE process was around 70% of those obtained with CE. However, the quality of extracts regarding radical scavenging activity and bioactive phenolic content was higher than those obtained by CE. F. sellowiana leave is a potential source of bioactive compounds with strong radical scavenging activity and the SC-CO2 extraction can be considered as a green technique to extract bioactive compounds.