Hazelnut represents one of the most consumed food, containing a large range of bioactive and health-promoting compounds. Investigation of the fatty component of C. avellana nut has been widely carried out, but little is known about its phenolic content. In order to achieve deeper insight into the polar fraction of the n-butanol extracts of both fresh and roasted kernels of C. avellana cultivar, “Tonda di Giffoni” a PGI (Protected Geographical Indication) product of Campania region (Italy), a phytochemical investigation was carried out. High performance liquid chromatography coupled to electrospray ionization, multiple-stage linear ion-trap and orbitrap high-resolution mass spectrometry (LC-ESI/LTQOrbitrap/MS/MSn) profile of the fresh and ro...