OP A5. DETERMINATION OF 13C/12C AND 18O/16O ISOTOPE RATIOS
IN FRUIT JUICES  AND ALCOHOL BEVERAGES

M. Čolović1, N. Ogrinc2, N. Miljević1

1 - Vinča Institute of Nuclear Sciences, POB 522, 11001 Belgrade, Serbia
2 - Department of Environmental Sciences, Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia

13C/12C ratio of sugars and pulp in selected fruit juice samples and alcohol from spirit samples was investigated using isotopic ratio mass spectrometry. Analyzed orange and apple juices were produced in Serbian factories and are available in Serbian market. Spirits were home made in different Serbian areas from several types of fruits. Additionaly, the friut juice samples were analyzed for 18O/16O ratio. The purpose of the analysis was to characterise the investigated products, establishing their authenticity and screening possible nonlegal addition of sugar. δ13C values of sugars in some fruit juices ranged between 22.2 and 14.3‰ and are higher than expected for the authentic fruit juices (δ13CVPDB = -25.5 ± 0.3‰). The difference between δ 13C  values of sugar and pulp in two fruit juice samples was significant. δ13C values of ethanol in two investigated spirit samples (-23.1 and -19.6‰) were higher than expected for these types of fruits (-26.3 ± 0.6‰).