Gas chromatography/mass spectrometry-based metabolite profiling of chia and quinoa seeds in comparison with wheat and oat

IntroductionWith an increasing interest in healthy and affordable cereal intake, efforts are made toward exploiting underutilized cereals with high nutritional values.ObjectivesThe current study aims to explore the metabolome diversity in 14 cultivars of chia and quinoa collected from Germany, Austria, and Egypt, compared with wheat and oat as major cereals.Material and MethodsThe samples were analyzed using gas chromatography-mass spectrometry (GC-MS). Multivariate data analysis (MVA) was employed for sample classification and markers characterization.ResultsA total of 114 metabolites were quantified (sugars, alcohols, organic and amino acids/nitrogenous compounds, fatty acids/esters), but the inorganic and phenolic acids were only identified. Fatty acids were the major class followed by amino acids in quinoa and chia. Chia and oats were richer in sucrose. Quinoa encompassed higher amino acids. Quinoa and chia were rich in essential amino acids. Higher levels of unsaturated fatty acids especially omega 6 and omega 9 were detected in quinoa versus omega 3 in chia compared with oat and wheat, whereas omega 6/omega 3 fatty acid ratio of chia was the lowest. To the best of our knowledge, this is the first comprehensive metabolite profiling of these pseudo cereals.ConclusionQuinoa and chia, especially red chia, are more nutritionally valuable compared with oat and wheat because of their compositional profile of free amino acids, organic acids, and essential fatty acids, besides their low omega 6/omega 3 fatty acid ratio. Such results pose them as inexpensive alternative to animal proteins and encourage their inclusion in infant formulas. Fourteen chia and quinoa seed cultivars were assessed for their primary metabolome compared with wheat and oats using GC-MS assisted by multivariate data analysis. A total of 114 metabolites were identified including sugars, organic acids and alcohols, amino acids, fatty acids/esters, and phenolic acids. Species-specific markers for each cereal type were obtained using OPLS-DA modeling of GC-MS datasets. Quinoa and chia, especially red chia, are proven to be more nutritionally valuable than oat and wheat.