Application of response surface methodology (RSM) for the optimization of supercritical CO2 extraction of oil from patè olive cake: Yield, content of bioactive molecules and biological effects in vivo

The two-phase technology for olive oil extraction generates large amounts of patè olive cake (POC), a by-productthat is rich in bioactive health-promoting compounds. Here, response surface methodology (RSM) was used tomaximize supercritical-CO2 oil extraction from POC, while minimizing operative temperature, pressure andtime. Under the optimal parameters (40.2 °C, 43.8 MPa and time 30 min), the oil yield was 14.5 g·100 g-1 dw(~65% of the total oil content of the freeze-dried POC matrix), as predicted by RSM. Compared with freeze-driedPOC, the oil contained more phytosterols (13-fold), tocopherols (6-fold) and squalene (8-fold) and was a goodsource of pentacyclic triterpenes. When the biological effects of POC oil intake (20-40 ?L·die-1) were evaluatedin the livers of BALB/c mice, no significant influence on redox homeostasis was observed. Notably, a decline inliver triglycerides alongside increased activities of NAD(P)H:Quinone Oxidoreductase 1, Carnitine Palmitoyl-CoA Transferase and mitochondrial respiratory complexes suggested a potential beneficial effect on liver fattyacid oxidation.