Figure 4.

Effect of temperature (A), pressure (B), time (C), and CO₂-to-mass ratio (D) on extraction efficiencies of total lipids, total fatty acids (TFAs), and γ-linolenic acid (GLA) by solid matrix-supported supercritical CO₂ (SMSSC-CO₂) extraction. Experiments were performed under the following conditions: diatomite-to-biomass ratio, 1:2 (w/w); water content of solid materials, 60 wt.%; ethanol-to-biomass ratio, 3:1 (v/w); and (A) pressure = 41 MPa, extraction time = 60 min (static extraction for 30 min + dynamic 30 min), CO₂-to-mass ratio = 2.0 mL g⁻¹ min⁻¹; (B) temperature = 40 °C; extraction time = 60 min (static extraction for 30 min + dynamic 30 min), CO₂-to-mass ratio = 2.0 mL g⁻¹ min⁻¹; (C) temperature = 40 °C, pressure = 41 MPa, CO₂-to-mass ratio = 2.0 mL g⁻¹ min⁻¹; (D) temperature = 40 °C, pressure = 41 MPa, extraction time = 60 min (static extraction for 30 min + dynamic 30 min). Error bars represent the standard deviation (n = 3).