Biofortification of food chain with selenium

Summary in the original language of the document

Selenium (Se) is an essential micronutrient for humans and animals which is circulated
to food chain via crop plants. Agronomic biofortification with Se is used in areas where
the soil Se content is low and Se deficiency causes health problems. Brassica species
are efficient in accumulation of soil Se and therefore an attractive choice of species for
biofortification. Se uptake and translocation was studied in B. rapa and B. napus in
field experiments applied with 0, 6 or 20 mg Se ha-1 as Na2SeO4 and foliar sprays of
30 mg Se ha-1 as Na2SeO4 or Na2SeO3. In addition, a HPLC-ICP-MS based method to
identify and quantify organic Se-compounds in seeds and meals was developed. High
concentration of Se accumulated in seeds (1.89 μg g-1) and after oil extraction Se
remained mainly in the meal fraction (1.34 μg g-1). Foliar spray of Na2SeO4 was most
efficient in increasing the meal Se concentration. Selenium specification studies
revealed that 68-82 % of Se was in a form of valuable selenomethionine (SeMet).
Other Se-compounds were not detected. At rosette stage, Brassica plants had taken
up 30-40% of applied Se but the translocation to seeds was low. The results show that
agronomic biofortification with Se can improve the nutritive quality of Brassica meal
due to high accumulation of SeMet and its stability during processing. The strategy to
improve the efficiency of agronomic biofortification with Se in Brassica is discussed.