Supercritical CO2 extraction of aspen bark (Populus tremula L.): Influence of operating conditions on yield, vitamin-E content and extract characterization

Aspen bark (Populus tremula L.) is known as a plant that consists of a medicinal compound (vitamin- E). Supercritical carbon dioxide extraction (SC CO₂) is one of the most efficient methods of extracting interesting compounds from plants. By altering pressure and temperature (operating conditions of the supercritical fluid process), the specific compound can be extracted. Based on the method of supercritical fluid extraction (SFE) technology using carbon dioxide, extracts of Populus tremula L. were obtained at a temperature of 313.15 K and pressures of (15, 20, 30) MPa. For a comparison of quantitative indicators of vitamin -E content and antioxidant properties, an extract of Populus tremula L. was obtained using a conventional method. The GC/MS analysis revealed the presence of vitamin- E in all three CO₂ extracts. The quantification of vitamin E was analyzed with gas chromatography (GC-MS). The vitamin -E yield was obtained at the highest condition of 30 MPa at 313.15 K with a yield of 8.5 %.