Phenolic Compounds from Sesame Cake and Antioxidant Activity: A New Insight for Agri-Food Residues' Significance for Sustainable Development

Agri-food residues represent a rich source of nutrients and bioactive secondary metabolites, including phenolic compounds. The effective utilization of these by-products in food supplements and the nutraceuticals industry could provide a way of valorization in the transition to becoming more sustainable. In this context, the present study describes the phenolic profiling of sesame (Sesamum indicum L.) cake using reversed-phase high-performance liquid chromatography coupled to diode array detection and quadrupole-time-of-flight-mass spectrometry. Compounds were characterized based on their retention time, UV spectra, accurate mass spectrometry (MS) and MS/MS data along with comparison with standards, whenever possible, and the relevant literature. The characterized compounds (112 metabolites) belong to several classes, namely, phenolic acids (hydroxybenzoic acids and hydroxycinnamic acids), flavonoids, and lignans. Moreover, organic acids and some nitrogenous compounds were characterized. The total phenol content and the antioxidant activity of the cake extract were determined. This study provides useful information for the valorization of by-products from the sesame oil industry.