As sesame seed is widely used by sprinkling over bakery products in Hungary, this study also
deals with the effect of a simulated bakery process on selenium species distribution. Since fatty seeds, like sesame tend to become rancid
in consequence of no appropriate or long storage time, the prospect of conversion of selenium species was under investigation. The sample
was analysed for total selenium and selenium speciation by the means of a coupled technique, HPLC–UV–HG–AFS. Peculiar attention
was paid to avoid the misidentification of selenium species when co-elution problems may occur by applying independent HPLC
separation techniques (cation and anion-exchange chromatographies). For validating the total Se measurements, a certified reference
material (BCR-422) was used. Different sample preparation techniques were applied to reach the maximal extraction efficiency. An adequate
extraction efficiency (83%) was achieved, making the quantification of selenomethionine (552 ± 14 lg SeMet as Se kg1 in the original
sesame) possible. Neither the simulated bakery process (roasting) nor forced oxidation caused any changes in the Se-species
distribution of sesame seeds.