UHPLC-ESI-QTOF-MS screening of lignans and other phenolics in dry seeds for human consumption

Abstract

Dry seeds are receiving increasing attention as functional foods, due to their high concentration of phenolic compounds and particularly of lignans. In this study, total phenolic content, antioxidant capacity and the whole phenolic profile of poppy, sunflower, pumpkin, sesame and flaxseed were determined. A deep profiling, firstly regarding phenolic compounds and then, more specifically, lignans, was carried out using liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS).All matrices were confirmed to be an excellent source of health-promoting compounds, although with marked differences. Sunflower is an excellent source of phenolics and showed the highest antioxidant capacity even though its lignan content is limited. Sesame and flaxseed provide a good source of phenolics, but their peculiar contribution is in term of lignans. Finally, pumpkin and poppy seeds contain a fair concentration of phenolics and a limited concentration of dietary lignans.