Multi-spectroscopic investigation of Crocus sativus L. tissues

The increasing interest on saffron, the most expensive spice worldwide obtained from dried red stigma of Crocus sativus L., over the last decades, is mainly due to its potential employment as a source of biologically active molecules and not only because of its use as a food additive. Other tissues of Crocus sativus L. could contain potentially bioactive molecules as well, like tepals, generally considered as byproducts and high resolution NMR spectroscopy allowed to investigate their content. The use of 1H NMR data combined with chemometrics allowed moreover to asses quality characteristics of saffron, like geographical origin, the storage period during which saffron can be considered as fresh and the detection of possible chemical- and bio-adulterants. In addition, the volatile fraction of stigma was characterized by GC-MS while the metabolic content of C. sativus L. tissues (stigma, stamens and tepals) was characterized with different spectroscopic techniques like HPLC-DAD, FT-IR, and Raman comparing the results with the NMR findings. The outcomes, highlighted the limitations of the current ISO procedures, thus suggesting a possible integration of ISO with advanced analytical techniques.