Thermodynamics and statistical correlation between supercritical-CO2 fluid extraction and bioactivity profile of locally available Mexican plants extracts

Supercritical-CO2 fluid extraction (SFE) is a green technology which is being used for the extraction of bioactive compounds such as pigments and fatty acids, in recent years. Naturally occurring plants or plant-based extracts are considered potential candidates with antioxidant and antimicrobial activities. Therefore, in this work, a range of locally available natural plants i.e. oregano, Mexican arnica also known as Heterotheca inuloides, lemon peel, and blackberry marc was analyzed for the extraction of high-value compounds. A multivariable linear regression model was used to analyze the output variables in relation with the inputs i.e. pressure (P), temperature (T), and co-solvent (CoS). Based on Arrhenius equation, the linear correlativity of the data with an activation energy Ea = 6064.14 kJ/mol and a pre-exponential factor of k0 = 0.388 s−1 were recorded. The thermodynamic parameters of enthalpy, entropy, and Gibbs free energy were also evaluated, correlating the thermodynamics with the extraction yield of the process.