APPLICATION OF COMPOUND SPECIFIC ISOTOPE ANALYSIS IN FOOD
N. Ogrinc and D. Potočnik
Jožef Stefan Institute, Department of Environmental Sciences
Jamova 39, 1000 Ljubljana, Slovenia
There is an urgent need for more sophisticated instrumentation and more appropriate analytical methods able to offer better qualitative and quantitative results on issues such as traceability, authenticity and origin of food and beverages. One such technique that shows a great potential in this area is compound specific isotope analysis (CSIA). In this presentation, a practical application of this method on fatty acid composition in oils and aroma compounds will be outlined. CSIA was applied to the analysis of fatty acids in false flax oil (Camelina sativa oil), olive and pumpkin oils for the purposes of authentication and determination of origin. For the adulteration, rapeseed oil, sunflower oil and soybean oil, that are cheaper and belong to different botanical famillies, were used. One hunderd % correct classification according to geographical and botanical origin in olive and pumpkin oil was obtained using the content and stable isotope analysis of fatty acids. The method was also applied to other products containing olive oil such as tuna canes. The results indicated that all investigated samples of tuna canes available on Slovenian market contain authentic olive oil. Further extraction of vanilla aroma from 14 different ice cream and yogurt on Slovenian market was performed to evaluate their authenticity based on the measured carbon isotopic composition. The results indicated that around 40% of samples
Nives Ogrinc obtained BS and MSc degrees in physical chemistry from the Faculty of Chemistry and Chemical Technology University of Ljubljana. She received PhD degree from the same faculty in 1997. Her PhD study was performed at Jožef Stefan Institute in the field of ecology using stable isotope approach to study carbonate system in different aquatic environments. Nives obtained NATO-postdoctoral fellowship from 2000-2002 in the Department of Chemistry at Trent University, Peterborough, Ontario, Canada. This fellowship offered her possibilities to be involved in a larger research project on mercury (Hg) cycling in Canada (METAALICUS) using stable isotopes of Hg. She works at the Department of Environmental Sciences as the Deputy Head of the Department and Head of the Group for Organic Geochemistry.
She is also a professor at the Jožef Stefan international postgraduate school. In food studies her work is related to the use of stable isotopes as tracers of the sources, origin and authenticity of various foodstuffs, such as honey, olive oil, wine, milk and fruit juice. Recently more research was performed on Compound Specific Isotope Analysis. She has published more than 110 papers, 10 book chapters, coordinated national and international projects and organized several workshops and conferences/symposiums. In addition she is a member of the Editorial board of the Journal of Soils and Sediments and a member of the expert group on Food Quality and Safety in the framework of the European Technology Platform 'Food for Life'.