Turkish extra virgin olive oils (EVOO) from different varieties/geographical origins and their phenolic compounds were investigated in terms of their antimicrobial and antioxidant properties in comparison to refined olive, hazelnut, and canola oils. Antimicrobial activity was tested against three foodborne pathogenic bacteria, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Enteritidis. Although all EVOOs showed a bactericidal effect, the individual phenolic compounds demonstrated only slight antimicrobial activity. Moreover, refined oil samples did not show any antimicrobial activity. Among the phenolic compounds, cinnamic acid (2 mg/kg of oil) had the highest percent inhibition value with 0.25 log reduction against L. monocytogenes. The synergistic interactions of tyrosol, vanillin, vanillic, and cinnamic acids were also observed against Salmonella Enteritidis. The antioxidant activities of oils were tested by β-carotene−linoleate model system and ABTS method. In both methods, EVOOs showed higher antioxidant activities, whereas refined oils had lower activity. The ABTS method provided a higher correlation (0.89) with total phenol content.

PEDOT electrodes were prepared in aqueous and organic solutions. A PEDOT-based sensor for the analysis of beverage antioxidants can be effectively prepared in propylene carbonate, and in this study, PEDOT polymerization was also performed in two aqueous solutions, 10% acetonitrile/water and an aqueous solution containing sodium dodecyl sulphate (SDS). The change in the oxidation potential of EDOT due to polymerisation solution was investigated and the film morphology was examined using SEM. The sensitivity of PEDOT sensors was tested by cyclic voltammetry in a gallic acid solution and with a green tea sample. The best sensitivity was obtained with PEDOT polymerized in propylene carbonate.