STABLE ISOTOPES DETERMINATIONS IN SOME FRUIT JUICES TO DETECT ADDED SUGAR
Marjan Guèek, Jože Marsel1* , Nives Ogrinc, Sonja Lojen Department of Analytical Chemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia, Department of Environmental Sciences, J. Stefan Institute, 1000 Ljubljana, Slovenia
A method was developed to detect the adulteration of fruit juices. By means of stable isotope determinations, it is possible to detect exogenous sugar addition to natural juices. Since sugars photosynthesized by the Calvin cycle (orange, apple, beet) have delta13C values much lower than their Hatch-Slack counterparts (cane sugar). Thus, it is possible to detect cane sugar addition. The deltaD in nitrated sugars enables the determination of beet sugar addition to natural juices. Commercially available Slovenian fruit juices were investigated. The results showed that none of the juices investigated was illegally adulterated.