Supercritical extraction of chia seed oil-experimental and modelling studies

Resumen del trabajo presentado a la IX Reunión de Expertos en Tecnologías de Fluidos Comprimidos (Flucomp), celebrada en el Campus UAM Cantoblanco (Madrid) del 13 al 15 junio 2018.Chia seeds (Salvia hispanica) contain a large amount of oil (25-35% mass of dry seed) rich in polyunsaturated fatty acids - particularly linoleic (15-20) % and linolenic (60-65) % - of the total fatty acids. In our work, the influence of supercritical extraction (SCE) operating conditions, namely temperature (40 and 60 ºC) and pressure (25 and 45 MPa) at a constant CO2 flow rate (40 g/min), on oil yield from chia seeds is studied and presented. The extraction curves obtained at the experimental conditions examined are shown on Figure 1. The highest oil recovery (90.3 %) was achieved at 60 ºC and 45 MPa, while the lowest (64.5 %) was obtained at 40 ºC and 25 MPa. In addition, the kinetics of the SCE process was modeled and reported for the first time applying an approach, which reflects in a rigorous way the interplay between phase equilibria (solubility) and kinetics. The approach was deployed, validated and executed using gPROMS Model Builder. For the purposes of modeling, chia seed oil was represented as triolein and the calculation of its solubility in the scCO2 at the temperatures and pressures of interest to the experiment was realized applying a rigorous thermodynamic modelling framework. The qualitative and quantitative agreement between the SCE experimental data and the extraction curves simulated was good.J. Coelho, R. Filipe, R. Stateva acknowledge the funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 778168.Peer reviewe