Monitoring in real time the changes in VOCs emission in sunflower and extra virgin olive oil upon heating by PTR-ToF-MS

In this work the emission of volatile organic compounds (VOCs) upon the heating process of an extra virgin olive oil (EVOO) and a high oleic sunflower oil (SFO) was evaluated in real time by spectrometry. Two tests were carried out, in the first VOCs emitted from both kinds of oil were measured at room temperatures (not heated, NH) and at 180°C; in the second test, VOCs emission for selected masses were monitored under increasing temperatures over time: at room temperature not heated oils (NH), 60, 90, 120, 150, and 180°C, respectively. The spectra were acquired using a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-ToF-MS). The total VOCs emission increased at 180°C, determined both by the rise of the amount of compounds present in the NH samples and by the formation of new masses generated by oxidative chemical reaction from triglycerides and fatty acids. From the set of results it is evident that a good control of the temperatures can be useful in reducing the quantities of masses potentially harmful to health in human food.