Oxidation products of free polyunsaturated fatty acids in wheat varieties

Oxygenated fatty acids (oxylipins) are secondary metabolites of polyunsaturated fatty acids (PUFA). Here, we present a novel high‐performance liquid chromatograpic separation on a reversed‐phase column (RP‐HPLC) coupled with electrospray ionization‐tandem mass spectrometry (ESI‐MS/MS) for the determination of various (per)oxidation products of linoleic (cis,cis‐9,12‐octadecadienoic) acid in eight different varieties (four spring and four winter varieties) of wheat (Triticum aestivum). The procedure includes extraction of oxylipins, chromatograpic separation using a linear gradient of aqueous formic acid and acetonitrile, with subsequent identification of compounds by MS/MS. Among the identified oxylipins, leukotoxin (LTX)‐diol and its isomer (iso‐LTX‐diol) are known as potentially toxic substances. The obtained data was used further for comparison of different wheat varieties by principal component analysis (PCA). From the results of PCA, differences can be observed in the patterns of wheat varieties.