Effects of Supercritical Carbon Dioxide Extraction (SC-CO2) on the Content of Triterpenoids in the Extracts from Ganoderma Lucidum

This research investigates the effect of SC-CO2 extraction parameters on the triterpenoid recovery from G. lucidum. The SC-CO2 parameters included extraction pressure, extraction temperature, and extraction time. The extraction pressure was varied between 200, 400 and 600 bar, the extraction temperature between 30, 55 and 80 °C, and the extraction time between 30, 75 and 120 min. In this study, the SC-CO2 parameters were first optimized using a response surface methodology (RSM) for maximum triterpenoid recovery. The results showed that the optimal RSM-based SC-CO2 conditions were 430 bar extraction pressure, 54.8 °C extraction temperature and 78.90 min extraction time, achieving the maximum triterpenoid recovery of 1.56 mg/100g. The kinetic behavior of SC-CO2 process was subsequently characterized using a second-order kinetic model under variable extraction pressures and extraction temperatures, given a SC-CO2 time interval. The second-order kinetic models represented well the experimental results of triterpenoid extraction by SC-CO2 method. At these conditions, the triterpenoid extract also exhibited strong scavenging activities with IC50 values of 0.49 mg/mL for the DPPH radical scavenging activity and 0.26 mg/mL for ABTS radical scavenging activity. Thus, triterpenoids extracted from G. lucidum could be regarded as a potential agent for medicinal treatment. The results also suggest that the SC-CO2 extraction can be a useful extraction method for triterpenoid extraction from G. lucidum