How does maturity stage affect seeds metabolome via UPLC/MS based molecular networking and chemometrics and in relation to antioxidant effect? A case study in 4 major cereals and legumes

Legumes and cereals as staple food are typically consumed at mature stage, though also consumed at earlier stages. UPLC/MS based molecular networking and chemometrics were employed for the first time to address metabolome composition heterogeneity amongst seeds in the context of their maturity stages. The study included 4 major cereal and leguminous seeds of different species, and cultivars i.e., Triticum aestivum, Hordeum vulgare, Vicia faba and Cicer arietinum. 146 Metabolites from various classes were identified of which several are first time to be reported. Supervised OPLS model of all datasets revealed that sugars and oxylipids were dominant in mature and immature seeds, respectively. DPPH and FRAP assays were assessed for differential secondary metabolites' correlation. Results were attributed to flavonoids, oxylipids, and amino acids/peptides. Mature barley seeds possessed the strongest antioxidant activity among examined seeds. This study provides novel insights on seeds' maturation process in context to holistic metabolic changes.

Automated summary

In this study, UPLC/MS and chemometrics were used for the first time to investigate the heterogeneity of metabolome composition among seeds at different maturity stages. 146 metabolites from various classes were identified, some of which were reported for the first time. Sugars and oxylipids were found to be dominant in mature and immature seeds, respectively. The correlation between differential secondary metabolites was evaluated through DPPH and FRAP assays, and flavonoids, oxylipids, and amino acids/peptides were found to be responsible. Mature barley seeds exhibited the strongest antioxidant activity. This study provides new insights into the maturation process of seeds and their metabolic changes.