Supercritical Fluid Extraction of Lemon Verbena (Aloysia triphylla): Kinetics, Scale-up and Chemical Composition

摘要

Supercritical fluid extraction (SFE) and low-pressure solvent extraction (LPSE) of lemon verbena were conducted. Kinetic parameters of the overall extraction curve (OEC) and scale-up data are presented. The scale-up criterion used (maintaining solvent to feed ratio constant) was successfully used for a 14-fold scale-up from laboratory to pilot scale. Maximum yield obtained for SFE was 1.8%, and for LPSE, 7.1%. The chemical composition revealed different chemical profiles for SFE and LPSE extracts; the last ones presented more flavonoids and other heavy compounds, while SFE extracts were more concentrated on volatile compounds. By manipulating separation conditions, three different products, of different physical-chemical properties, were obtained in the three series separators of the pilot equipment. Therefore, the purpose of using the extract should influence the decisions of which are the best extraction method and the best operational conditions.