Comprehensive metabolomics and antioxidant activity of Allium species viz. Allium semenovii, A. sativum and A. cepa: An important spice

Allium is one of the most extensively consumed spices in most parts of the world. While Allium cepa and A. sativum have wide spread cultivation, A. semenovii is only found in high altitude areas. Increasing utilization of A. semenovii needs a comprehensive understanding of its chemo-information, and health benefits in comparison to well explored Allium species. The present study compared metabolome and antioxidant activity in tissues extracts (Ethanol, 50% ethanol and water) of leaves, roots, bulbs, and peels of the three Allium species. All samples showed significant polyphenols (TPC: 167.58-0.22 mg GAE/g and TFC: 164.86-2.2 mg QE/g) content with higher antioxidant activity in A. cepa and A. semenovii than A. sativum. UPLC-PDA based targeted polyphenol also showed highest content in A. cepa (peels, roots, and bulbs) and A. semenovii (leaves). Further, 43 diversified metabolites including polyphenols and sulphur containing compounds were identified using GC-MS and UHPLC-QTOF-MS/MS. The statistical analysis (Venn-diagram, Heatmap, stacked charts, PCA, PCoA) of identified metabolites in different samples revealed the similarities and discriminations among different species of Allium. The current finding illustrated potential of A. semenovii for utilisation in food and nutraceuticals.