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

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