Effect of Supercritical CO2 and Microwave-assisted Extraction Methods on Bioactive Compounds Extraction from Silybum marianum Seed

In the current study, the effect of different new extraction methods including supercritical carbon dioxide extraction (SC-CO2), microwave-assisted extraction (MAE) and also conventional Soxhlet extraction (CSE) were investigated on bioactive compounds recovery from Silybum marianum seed. The crude extraction yield (22.40± 0.15%) was obtained using CSE, while the efficiency of SC-CO2 and MAE were about 89 and 50% of those obtained using CSE. The highest free radical scavenging activity in terms of DPPH and HO radicals was obtained in extract obtained using SC-CO2. From the TPC analysis, the highest and lowest value was determined in extracts obtained using SC-CO2 (102.93± 0.14 mg GAE/g) and CSE (14.50± 0.18 mg GAE/g), respectively. Fatty acid composition was analyzed using Gas Chromatography–Mass Spectrometry. Linoleic and oleic acids were determined as the main fatty acids. Finally, it can be concluded that S. marianum seed is a potential source of bioactive compounds and new extraction techniques of SC-CO2 and MAE could be suggested as promising methods to substitute conventional method for successful recovery of bioactive compounds.