ABSTRACT
Thirty-two bottled and canned cider samples, purchased from Romanian market, were analyzed for their stable isotope ratios and elemental profiles to verify their authenticity. The determination of δ18O values of water from ciders for the detection of exogenous water and the determination of δ13C from ethanol and dry substance used to evaluate the addition of cane sugar or corn glucose syrup were performed for all the samples. Also, an investigation of the differences that occur in terms of elemental profile among cider samples was performed. All samples from the same producer, besides their natural ingredients, had some exogenous ingredients, which make them different from similar samples from another producer which probably uses other exogenous ingredients. Potassium was the element at the highest concentration in the samples. The heavy metal concentrations do not pose any health risk.