Metabolomic insights into Triticum aestivum L.: comparative profiling of growth stages and parts using hydrophilic extracts

Abstract Despite wheat being a vital global food source, its metabolomic profile across different growth stages and anatomical parts (e.g., germ and bran) remains underexplored, particularly in relation to its known antioxidant potential. In this study, an untargeted, comparative metabolomic analysis of hydrophilic extracts from wheat was performed across ten distinct growth stages and the metabolomes were further related with in vitro antioxidant activity. Using GC-MS, principal component analysis (PCA) revealed distinct grouping of samples from early root stages (stages 1 and 2) and the aerial part of stage 3. Variable importance in projection (VIP) scores identified five key discriminant metabolites, including sugars, phenolic acids, and amino acids. In contrast, LC-MS/MS-based PLS-DA clearly separated seed parts from other tissues, with VIP scores highlighting flavonoids and phenolic acids as primary contributors to variation. Among the examined stages and tissues, the aerial part of stage 3 showed the highest total phenolic content and strongest antioxidant activity, indicating its potential nutritional value despite being typically disregarded. A total of 29 and 43 compounds were annotated via GC-MS and LC-MS/MS, respectively, including several known for antioxidant activity such as l-proline, sucrose, myo-inositol, caffeic acid derivatives, coumaric acid isomers, catechin, and vitexin. This study is the first to use an untargeted metabolomic approach to explore the differences in phytoconstituents across wheat growth stages and parts, highlighting the antioxidant potential and health benefits of these segments and expanding the interest in the nutritional value of wheat beyond the most commonly ingested seeds and germ.