Concentration of the oxyterpenes linalool and α-terpineol in orange peel oil by supercritical fluid adsorption

Abstract

The concentration of oxygenated monoterpenes (oxyterpenes) in orange peel oil by supercritical fluid adsorption (SFA) was investigated varying pressure (10–24 MPa) and temperature (40–60 ºC) and using silica aerogels as adsorbent. Dynamic solubility experiments were conducted to obtain the solubility of the monoterpenes in supercritical CO₂, revealing that it increases with pressure regardless of temperature. For SFA, 10 MPa and 60 ºC was the most appropriate condition to concentrate oxyterpenes, leading to the lowest solubility of oxyterpenes and highlighting the advantage of lower densities for SFA’s selectivity. Furthermore, this condition yielded the highest concentration factors for oxyterpenes (4.3 for linalool and 6.5 for α-terpineol) within the 80–90 min interval. These findings contribute with valuable insights to SFA processes to concentrate oxyterpenes from orange peel oil, which has the potential to enhance the market value and functionality of this important product from citrus industries.