Extraction of pungent components from Japanese pepper (Xanthoxylum piperitum DC.) using supercritical CO₂

Supercritical CO₂ extraction of pungent components from immature and mature Japanese pepper has been conducted in order to study the effect of extraction condition on the yield of extract and composition of pungent components in the extract. Extraction was carried out in semi-continuous extractor at pressure of 9-45 MPa, temperature of 40-80 °C and CO₂ flow rate of 1-3 mL/min. Composition of pungent compounds in the extract was analyzed by GC-MS, while sanshool compounds was qualitatively analyzed by HPLC-DAD. Extraction condition significantly affected the yield of extract and the composition of pungent components in the extract. In general, extraction yield of mature Japanese pepper was higher than immature one. Extraction condition can be tuned to obtain higher content of the target pungent components. The extract was mainly contained hydroxy-α-sanshool as the most abundant of sanshool compounds followed by α- and δ-sanshool. As comparison with the conventional methods, supercritical CO₂ extraction effectively extracted the pungent components of Japanese pepper in high yield.