The complex manufacturing process, as well as the growing demand for extra virgin olive oil, results in a high market price. This makes EVOO prone for adulteration, not only with other types of oils but also with refined olive oil. The international olive oil council (IOC) describes various physicochemical parameters and organoleptic methods and standards to define different olive oil qualities. Traditional wet chemical methods become, however, increasingly unacceptable by the industry since they require chemicals and solvents, creating health and safety risks, as well as environmental issues.
To evaluate FT-NIR spectroscopy as an alternative analysis method, more than 300 samples of extra virgin olive oils from different countries, at different age level and qualities were checked by an officially assigned sensory panel. Simultaneously, analytical parameters relevant for the quality, such as fatty acid composition, Anisidine value, free fatty acid content, K-Values Pyropheophytine, and 1,2-Diglyceride ratio, have been determined.
High calibration accuracy was obtained for the NIR determination of the listed analytical parameters. The results suggest that FT-NIR may offer a powerful tool for the quality control of extra virgin olive oils. Moreover, recent studies are presented to see, if adulteration with low-priced plant oils like hazelnut oil can be detected and if so, down to which level.
Presenter: Dagmar Behmer – Bruker