Chemometric analysis of Tunisian durum wheat metabolites using UPLC-ESI-QTOF-MS/MS

Bioactive compounds in wheat have received a great interest in the last few years due to their nutritional and health benefits. Various analytical procedures were used to identify these compounds in wheat kernels. An ultra-performance liquid chromatography coupled to electrospray ionization quadrupole-time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS/MS) was used for the screening of bioactive compounds in seven Tunisian durum wheat extracts. The aim of this study was to realize a screening of several classes of bioactive compounds in the same analysis and to identify specific metabolite markers for discriminating the durum wheat varieties. The UPLC-ESI-QTOF-MS/MS allows the detection of 81 metabolites, belonging to different chemical families such as sugars, organic acids, amino acids, fatty acids, and phenolic compounds represented by benzoic and cinnamic acid derivatives, phenolic alcohols, flavones, lignans, and condensed tannins. Chemical profiles identified varied greatly between different wheat genotypes. As far as the authors know, this is the first time that different chemical classes were detected at the same time in durum wheat kernels using UPLC-ESI-QTOF-MS/MS. This study gives the most complete map of metabolites in Tunisian durum wheat and proves that UPLC-QTOF-MS/MS coupled with chemometric analysis is a great tool for discrimination between durum wheat cultivars.