Quality evaluation and origin traceability of the imported and domestic saffron spice (Crocus sativus L.) products in China market using chemical composition and stable isotope analysis

Saffron spice, as a high value-added but not high-tech processed agricultural product, is easily faked and mislabeled its quality grade and origin for higher market profits and competitiveness. In this work, an analytical strategy combining chemical composition analysis and stable isotope ratio analysis of saffron spices was explored for verifying their quality and origin authenticity in China market. The crocins contents and stable isotope ratios of 70 saffron spice samples collected from five provinces of China and 95 imported products from Iran and Spain were determined together. The contents of crocins may be effective as the indexes of their quality evaluation but not for origin traceability. Relatively, regional difference of stable isotope ratios is significant (p < 0.05) between different origins. Partial least-squares discriminant analysis (PLS-DA) based on chemical compositions and stable isotope ratios of 165 saffron spice samples can identify imported products from Iran and Spain with the accuracies of 98.5 % and 100 %, but still may mis-discriminate samples from Henan and Xinjiang province of China as Iran products, which was further solved by PLS-DA of products from these origins. This strategy is promising as an effective tool for combating commercial frauds and ensuring the authenticity of saffron spice in China market.