Response surface methodology for supercritical CO2 extraction and microencapsulation of multi-components from “Pericarpium Citri Reticulatae - Fructus Aurantii” contained in herbal formulations

Abstract

To optimize the retention of the lipophilic compounds and aromatics, this study integrates supercritical CO₂ extraction (SCE) and microencapsulation technologies applied to "Pericarpium Citri Reticulatae - Fructus Aurantii" (PCR-FA). A three-factor, three-level experimental design employing response surface methodology (RSM) was conducted to assess the impact of pressure (P), temperature (T), and time (t) on the total extraction yield (Y) and the concentration of key constituents. The analysis of SCE products was performed using both sensory analysis and an electronic nose, followed by microencapsulation through complex coacervation. The findings revealed the presence of volatile terpenoids, lipophilic flavonoids, fatty acids, and sterols, with pressure exerting the significant influence on Y. Also extreme values of T and t adversely impacted the extraction efficiency. A sophisticated interaction among P, T, and t was demonstrated in the extraction of terpenoids, flavonoids, and lipids. An advanced adaptive chaotic grey wolf optimizer (ACGWO) pinpointed optimal conditions at 400 bar, 48 °C, and 87 minutes. The PCR-FA extracts exhibited distinctive olfactory traits and a unique electronic nose profile, differentiating them from individual herbal extracts. Post-microencapsulation, electron microscopy and ultraviolet (UV) spectroscopy confirmed a tri-layer structure encapsulating the SCE constituents. This investigation lays a scientific groundwork for the extraction and stabilization of active components from Citrus-based herbal combinations, offering substantial insights for the enhancement of Chinese patent medicine production through validated models and optimization algorithms.