Effect of different extraction techniques on total phenolic content and antioxidant activity of Quercus infectoria galls.

In this work, the bioactive compounds which was obtained by extracting Quercus infectoria via two extraction methods; Soxhlet and supercritical carbon dioxide (SC-CO 2 ) extraction, were analyzed using total phenolic content and DPPH (2,2-diphenyl-1-picryl hydrazyl) free radical scavenging activity analysis. The aim of this study is to compare the total phenolic content and antioxidant activity of Quercus infectoria extract acquired from SC-CO 2 extraction with those from Soxhlet extraction method. The results showed the used of SC-CO 2 extraction give the lowest extraction yield as compared to Soxhlet extraction. The selectivity of Q. infectoria extracts using SC-CO 2 extraction was better which in contrast with Soxhlet extraction method since it shows higher total phenolic content (143.75 ± 1.06 mg GAE/g sample). This study also revealed that the extracts from both extraction methods can posses’ antioxidant activity and comparable to those obtained from commercial antioxidant.