Combined effects of genotype and harvest year on the distribution patterns of avenanthramide forms in oat varieties: considerations regarding the classification of “major” and “minor” forms

• Eleven winter and eight spring oat varieties tested for avenanthramides (AVNs) • Two consecutive harvesting years monitored (2021, 2022) • Novel extraction methodology with acetonitrile/water/formic acid is suggested • LC-ESI-HR AM MS based identification and quantification • Higher concentrations of “minor” AVNs (D, O/R, Q/T) detected compared to A, B and C The distribution and concentration of avenanthramides (AVNs) in oats shows high variability with an unearthed pattern influenced by genetic variability and harvest year (proxy for exposure to different abiotic stresses). Our study aimed at screening the variation of AVNs in an oat population consisting of eleven winter and eight spring oat accessions harvested in 2021 and 2022. For this analysis, a new extraction method using acetonitrile/water/formic acid was applied. Liquid chromatography - electrospray ionization - high resolution mass spectrometry was used for the identification of “major” and “minor” AVN subtypes with the help of authentic standards and through accurate mass screening and MS/MS analyses for “minor” subtypes. The concentration of AVNs (A: 1.28 – 20.7 mg kg -1 ; B: 3.64 – 26.6 mg kg -1 ; C: 1.03 – 56.5 mg kg - 1; D: 2.46 – 4.26 mg kg -1 ; O/R: not detected – 3.90 mg kg -1 ; Q/T: not detected – 4.15 mg kg -1 ) proved to be significantly genotype-dependent and strongly influenced by the harvest year. The individual concentration of “minor” AVN subtypes exceeded those of the “major” AVNs in almost half of the oat varieties tested, which calls attention to the re-evaluation of AVN distribution patterns.