Response surface methodology for the optimization of phenolic compounds extraction from extra virgin olive oil with functionalized gold nanoparticles

The optimization of phenolic compounds extraction from extra virgin olive oil (EVOO) was achieved applying a Response Surface Methodology. A simple and straightforward method for the extraction of phenolic compounds from EVOO has been optimized in the presence of functionalized gold nanoparticles (AuNPs). AuNPs were prepared in the presence of Cysteamine as stabilizing thiol (AuNPs-Cys) in order to obtain a water stable colloidal suspension. The obtained AuNPs-Cys, with mean size of about 10 nm were observed by AFM and used as extracting phase of phenolic compounds from EVOO. External parameters influencing the extraction were studied and a Central Composite Design (CCD) was applied for the optimization. The role of AuNPs-Cys quantity (4–12 mg), mixing and contact time (30–120 min), interfering (olive oil quantity) and phenolic compounds concentration (50–500 ppm) were analyzed. An equation model was obtained by applying CCD, with a high significativity (p < 0.0001) and low coefficient of variation value (CV = 3.14%). Optimization of extraction conditions were modulated up to 99%. This model allows to select the optimal extraction conditions to achieve the best performances and can be widely applied.