Application of a comprehensive metabolomics approach for the selection of flaxseed varieties with the highest nutritional and medicinal attributes

Abstract

Flaxseed is considered an indispensable generally recognized as safe (GRAS) source of polyphenolic lignans, polyunsaturated fatty acids (PUFA), fibers as well as minerals and vitamins. The metabolite content of flaxseed reflects its nutritional and medicinal value. Therefore, the selection of flaxseed variety for food industry is dependent on its metabolome. A metabolomics approach based on liquid or gas chromatography coupled to mass spectrometry has been applied to discriminate different flaxseed cultivars that are commercially available in Egypt. The available Sakha cultivars were subjected to a comprehensive metabolomics and lipidomics approach for investigation of their metabolomes. Our results showed that among the screened cultivars, Sakha 6, with its yellow-colored testa, showed marked metabolic discrimination. This yellow cultivar showed high accumulation of essential amino acids. Additionally, the oil of this cultivar accumulated the highest content of the two essential PUFA: alpha-linolenic acid (an ω -3 fatty acid) and linoleic acid (an ω -6 fatty acid). Interestingly, the content of the main antinutritional cyanogenic glycosides such as linustatin and neolinustatin was lower, while, the content of medicinally-important secondary metabolites was higher in Sakha 6 cultivar. These results support the use of this cultivar for human consumption owing to its high nutritional and medicinal value.

Features of Profiles of Biologically Active Compounds of Primary and Secondary Metabolism of Lines from VIR Flax Genetic Collection, Contrasting in Size and Color of Seeds

“…Perhaps, some part of the Xyl and Glc is accounted for xyloglucan. Contrary to our results, Salem et al [ 43 ] in flax metabolom analysis were able to identify a high content of Rha , Fuc as well as Xyl , however, Ara was not detected. The leaders in content, as in our experiment, were Raf and Suc , but in comparison with them, the level of Mylib was two orders of magnitude lower.…”

“…Salem et al [ 43 ] in flax metabolomic analysis showed approximately the same ratio of basic polyatomic alcohols as it occurred in our experiment, when glycerol, galtl , mInosl (and possibly Inosl similar to it) showed order of magnitude greater amounts than erythl and xylt . They did not identify mannitol and its stereoisomer dultl , but isolated their stereoisomer sorbitol.…”

“…Our method proved to be more productive in the isolation of organic acids and allowed the identification of 23 substances, compared to that of Salem et al [ 43 ] which identified16 substances of which 6 coincided ( phosph , malic , oxalic , succinic , purivic , threonate ). The ratio of all of them except threonate appeared to beproportional to our data, which was much larger.…”

“…Salem et al [ 43 ] in flax metabolom analysis identified 19 out of 20 proteinogenic amino acids. The leaders, such as in our experiment, were Pro , Ala , Asp , as well as tryptophan, which we did not identify.…”

“…Despite the apparent differences between yellow and brown seeded genotypes, we found only one publication analyzing the complex divergence of substances in them. Salem et al [ 43 ] evaluated the differences between 4 brown-seeded and one yellow-seeded varieties of linseed grown in three locations in Egypt. The authors showed that the yellow-seeded variety Sakha 6 accumulated significantly higher amounts of several amino acids, ( His , Ala , Gly , Arg, Ser , Met, Val , Tyr , Phe , Gln ), but the total protein content did not differ significantly among the tested varieties.…”