Differentiation of saffron geographic origin by stable isotope (C, H, O, N) and 87Sr/86Sr analysis

Saffron is regarded as the most expensive spice, due to its laborious production and the required environmental conditions. Iran accounts for ca. 90% of the global saffron production. Very often, saffron of a production other than Iran is significantly more expensive than Iranian saffron. As fraught and mislabeling with respect to saffron is common, besides tools for the control oft he authenticity of saffron (detection of fake-saffron), also techniques are required to control the declared origin of saffron, to prevent consumer deception.In the present study I compare C-, H-, O-, N- isotope patterns of saffron samples of various geographic origin. Furthermore, 87Sr/86Sr of saffron samples are investigated and compared.The results show notable variations of the isotope patterns of saffron samples of different geographic origin, but also of different vintages for samples of same geographic origin. 87Sr/86Sr results indicate a good differentiation for certain countries of origin (e.g. Morocco and India), but other geographic origins cannot satisfyingly differentiated. The discrimination of Iranian saffron from saffron of other geographic origin remains a challenging task.