Geographical origin identification of garlic cultivated in Korea using isotopic and multi-elemental analyses

Authentication of geographical origin is important in protecting agricultural products with registered trademarks. This study determined the geographical origin of garlic cultivated in the Republic of Korea using stable isotope ratios and multi-element concentrations. The isotope ratio reflected cultivation practice and environmental conditions. The major (Ca, Mg, P, S, Al, and Sr) and trace (As and Se) element concentrations were influenced by the bedrock in the garlic cultivation regions. Discriminant analysis (DA) using selected variables for garlic from different cultivation regions showed that 89% of the garlic was correctly classified according to the region of geographical cultivation with different lithological and climatic conditions. Stable isotopic compositions coupled to element concentrations showed better discriminating power than DA only with stable isotopic compositions or element concentrations. Therefore, the combination of a stable isotope ratio and multi-elemental concentrations is a useful tool for identifying garlic from different geographical origins. •The geographical origin of garlic could be distinguished with isotopic/elemental analyses.•The stable isotope ratios of garlic produced in different regions were significantly different.•The element contents of garlic reflected the lithological properties.•89.1% of the garlic cultivated regions were correctly classified by discriminant analysis.