How do cultivar origin and stepwise industrial processing impact Sesamum indicum seeds' metabolome and its paste and in relation to their antioxidant effects? A case study from the sesame industry

Abstract

Sesame is a valuable crop recognized for its rich composition and myriad of health benefits. The current study attempts to characterize sesame seeds' metabolome in relation to geographical origins i.e., Egypt, Sudan, Nigeria, in addition to samples from paste production lines along its different steps. UPLC-PDA-ESI-qTOF-MS was employed for untargeted profiling and in correlation to antioxidant capacity using DPPH, FRAP and β-carotene-lineolate assays. 139 Peaks were identified, including novel phospholipids and catechol lignan in sesame. Furthermore, discriminatory markers belonging to coumarins, lignans, phenolic and organic acids were revealed among raw accessions, whereas roasted and unroasted seeds were distinguished by sugar, peptide/amino acid, and organic acid contents. Negative processing impact was observed in the loss of lignans during dehulling and decreased antioxidant capacity in sesame paste. However, malic acid in roasted seeds and verbascoside in Nigerian sesame could account for their improved antioxidant effects as revealed using chemometrics.

Keywords: Antioxidants; Chemometrics; Food processing; Phenolics; Roasting; Sesame paste; Sesamum indicum; UPLC-PDA-qTOF-MS.