Biofortification of food chain with selenium

摘要

udSelenium (Se) is an essential micronutrient for humans and animals which is circulatedudto food chain via crop plants. Agronomic biofortification with Se is used in areas whereudthe soil Se content is low and Se deficiency causes health problems. Brassica speciesudare efficient in accumulation of soil Se and therefore an attractive choice of species forudbiofortification. Se uptake and translocation was studied in B. rapa and B. napus inudfield experiments applied with 0, 6 or 20 mg Se ha-1 as Na2SeO4 and foliar sprays ofud30 mg Se ha-1 as Na2SeO4 or Na2SeO3. In addition, a HPLC-ICP-MS based method toudidentify and quantify organic Se-compounds in seeds and meals was developed. Highudconcentration of Se accumulated in seeds (1.89 μg g-1) and after oil extraction Seudremained mainly in the meal fraction (1.34 μg g-1). Foliar spray of Na2SeO4 was mostudefficient in increasing the meal Se concentration. Selenium specification studiesudrevealed that 68-82 % of Se was in a form of valuable selenomethionine (SeMet).udOther Se-compounds were not detected. At rosette stage, Brassica plants had takenudup 30-40% of applied Se but the translocation to seeds was low. The results show thatudagronomic biofortification with Se can improve the nutritive quality of Brassica mealuddue to high accumulation of SeMet and its stability during processing. The strategy toudimprove the efficiency of agronomic biofortification with Se in Brassica is discussed.