Identification of chia, flax and sesame seeds authenticity markers by NMR-based untargeted metabolomics and their validation in bakery products containing them.

Chia, flax, and sesame seeds are considered superseeds due to their beneficial nutritional properties, and they are frequently included as functional ingredients in foods. Authenticity markers of these seeds, including bakery products containing them, have been identified by both liquid and gas chromatography coupled to mass spectrometry (LC-MS/MS and GC-MS/MS, respectively) targeted metabolomics. However, there are no reports describing the use of nuclear magnetic resonance (NMR) spectroscopy based metabolomics to identify authenticity markers in either the raw seeds or foods containing them. We herein report the application of an untargeted NMR-based metabolomics workflow to the identification of authenticity markers for the three seeds. Seven markers, belonging to the families of polyphenols and cyanogenic glycosides, allowed good differentiation of the raw materials. Validation in cookies containing different seed percentages showed that two markers resisted the processing stage, making them feasible authenticity markers for the food trade.