Extraction of limonoids using micro bubble supercritical carbon dioxide

A new technique of supercritical carbon dioxide (SC-CO₂) treatment, micro bubble SC-CO₂ method, was applied to extraction of limonoids. This method could increase the concentration of SC-CO₂ in sample solutions rapidly, so that limonoids were extracted effectively compared with conventional technique. Juice (sample A) and seed extract (sample B) of Natsudaidai were treated at 25 MPa, 35°C. The flow rate of CO₂ was 4 g/min. The yield of limonoids was significantly higher than those extracted by conventional SC-CO₂ method. When the extraction was carried out for 30 min, the extraction yield of limonoids in sample A and sample B were 92.5% and 42.4%, respectively. When methanol was added as an entrainer, the yield of sample B was increased up to 73.2%.