Supercritical fluid technology for lupin hulls valorization: extraction and fractionation of lupeol

Extraction of lupeol from lupin hulls has been carried out using supercritical CO₂ extraction technology under different operating conditions in order to obtain value-added extracts from the raw material of industrial lupin. The operational parameters used include CO₂ pressure and flow and sequential depressurization fractionation. The highest lupeol recovery (96.8%) has been obtained using 320 bar and 50 g/min of CO₂. For sequential depressurization, the best results were obtained with a CO₂ density close to 728 kg/m³ providing up to 92% of lupeol in the extract and an enrichment factor of 1.2. Despite this high enrichment, lupeol recovery decreases to 50% after fractionation. Better extraction recoveries would have been expected and thus further studies are necessary to improve the extraction recovery of extracts with a high lupeol composition.