Mandarin and Lime Peel Oil Processing by Supercritical CO₂Desorption: Deterpenation and High Molecular Weight Compounds Elimination

Desorption of mandarin and lime peel oils from a polar adsorbent was performed by supercritical CO2 to selectively eliminate terpene hydrocarbons and high molecular weight compounds (like paraffins, coumarins, psoralens and polymethoxyflavones) thus improving the oil quality. Peel oil fractionation was obtained starting the desorption process at 40°C temperature and 75 bar pressure and by stepwise increasing pressure to 85 and 100 bar. Three fractions were characterized by GC/MS analysis: terpenic fraction, deterpenated fraction and residue. The content of oxygenated compounds in the deterpenated fraction was 43 times higher than in the crude oil in the case of mandarin and three times higher in the case of lime oil. Coumarins, psoralens, polymethoxyflavones and waxes contained in the starting material were also identified in the mandarin residue fraction.