Using isotopic characterization to identify the authenticity of Ilex paraguariensis brands marketed in southern Brazil

Yerba mate (Ilex paraguariensis) has both economic and cultural importance in South America. However, due to a lack of quality control during processing, adulteration can occur. The aim of the study was to measure adulteration of yerba mate brands marketed in southern Brazil with sucrose, through isotopic characterization. Fifteen brands from local grocery stores were analyzed using eight samples of yerba mate derived from plants of different environments. Five samples of other species of Ilex genus and Ligustrum japonicum, which commonly contaminate yerba mate, were also tested. The isotopic composition of C (δ13C) and % N pointed out that some brands may have been adulterated with sucrose and a combination of % N and δ15N may be sufficient to identify contamination by leaves from other species. This study shows that isotopic characterization can potentially identify yerba mate that is adulterated with sucrose, and this method can also be used for quality control in food industry and to warrant further investigation.