Characterization and Discrimination of Ancient Grains: A Metabolomics Approach

Abstract

Hulled, or ancient, wheats were the earliest domesticated wheats by mankind and the ancestors of current wheats. Their cultivation drastically decreased during the 1960s; however, the increasing demand for a healthy and equilibrated diet led to rediscovering these grains. Our aim was to use a non-targeted metabolomic approach to discriminate and characterize similarities and differences between ancient Triticum varieties. For this purpose, 77 hulled wheat samples from three different varieties were collected: Garfagnana T. turgidum var. dicoccum L. (emmer), ID331 T. monococcum L. (einkorn) and Rouquin T. spelta L. (spelt). The ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC-QTOF) metabolomics approach highlighted a pronounced sample clustering according to the wheat variety, with an excellent predictability (Q2), for all the models built. Fifteen metabolites were tentatively identified based on accurate masses, isotopic pattern, and product ion spectra. Among these, alkylresorcinols (ARs) were found to be significantly higher in spelt and emmer, showing different homologue composition. Furthermore, phosphatidylcholines (PC) and lysophosphatidylcholines (lysoPC) levels were higher in einkorn variety. The results obtained in this study confirmed the importance of ARs as markers to distinguish between Triticum species and revealed their values as cultivar markers, being not affected by the environmental influences.

Effects of different cooking and drying methods on phenolic acids, carotenoids, and antioxidant activity of emmer (Triticum turgidum ssp. dicoccum) bulgur

“…Primitive wheats, which are the basic foodstuff of the humankind before the modern wheats, have started to attract attention again in the last period. This renewed interest is associated with the higher contents of soluble dietary fiber, proteins, lipids, rapidly digestible starch, Li, Mg, P, Se, and Zn, and high concentration of antioxidant compounds compared to bread wheat (Righetti et al, 2016). monococcum), emmer (Triticum turgidum ssp.…”

“…In addition, thanks to their both nutritive and functional properties, they have started to increase production areas and markets in various regions (Arzani & Ashraf, 2017). This renewed interest is associated with the higher contents of soluble dietary fiber, proteins, lipids, rapidly digestible starch, Li, Mg, P, Se, and Zn, and high concentration of antioxidant compounds compared to bread wheat (Righetti et al, 2016). In some primitive wheats, unique composition of secondary metabolites such as carotenoids was reported, which have functional properties (Curna & Lacko-Bartosova, 2017).…”

Variability and Site Dependence of Grain Mineral Contents in Tetraploid Wheats

“…Consequently, OPLS-DA models using the two cultivation sites as a discriminating category were built for each of the wild wheat accessions and the obtained predictive ability (expressed by Q 2 values) that was evaluated. This operating system could be successfully used in order to reveal potential differences between the wild wheat genotypes with respect to their cultivation site-dependence [60]. Among the wild wheat types, the MG29896 accession was the least affected from the cultivation site, having the lowest Q 2 , followed by MG4330, MG4343, MG5323.…”

Lipid profiling and analytical discrimination of seven cereals using high temperature gas chromatography coupled to high resolution quadrupole time-of-flight mass spectrometry

“…by PCA based on relative AR distribution, and were able to achieve a separation of einkorn (diploid) from emmer and durum wheat (both tetraploid) and spelt and bread wheat (both hexaploid), but the two hexaploid wheats were not separable (Ziegler, Steingass, Longin, Würschum, Carle, & Schweiggert, 2015). Righetti et al achieved a separation of einkorn, emmer, and spelt as well as durum and bread wheat by PCA based on non-targeted lipid profiles acquired by high resolution LC-MS (Righetti, Rubert, Galaverna, Folloni, Ranieri, Stranska-Zachariasova, et al, 2016;Righetti, Rubert, Galaverna, Hurkova, Dall'Asta, Hajslova, et al, 2018). As far as can be ascertained, this study is the first to successfully discriminate seven cereals, including four closely related Triticum species, based on their lipid profiles.…”

“…APCI or ESI) and polarity (positive or negative). In reference experiments, LC-MS with ESI in positive mode was found to be very useful for the analysis of phospholipids, but alkylresorcinols were not detectable using this approach and required use of APCI or negative ionisation ESI (Knödler, Berardini, Kammerer, Carle, & Schieber, 2007;Righetti, et al, 2016). Accordingly, lipid profiling by LC-MS is not straightforward; both GC-and LC-based methods have their individual advantages and weaknesses.…”