Fatty acids profile in Zn and Fe biofortified wheat grown under field conditions

The aim of this work is to compare fatty acids profiles of wheat grains (Triticum aestivum L. cv Nabão) sown in the field (Elvas, South Portugal, 38º 53' 15''N; 7º 08' 42''W), and to find differences related with previous biofortication of parental seeds. Such seeds were obtained in a previous study (Lidon et al., 2011) and were biofortified with zinc and iron. The seeds that were sown are designated by 2Ts, which contained 9.9 and 3.9 fold more zinc and iron, respectively, than original seed (non-biofortified, farmer seed) and 2T5s, which contained about 8.9 and 5.0 fold more zinc and iron, respectively, than original seed.Grains were ground in a flour mill, and total lipids were extracted with n-hexan (Zayas and Lin, 1989, modif.). Samples were saponified and methylated with BF3-methanol, using heptadecanoic acid (C17:0) as internal standard. The fatty acid methyl esters were analyzed with a gas-liquid chromatograph using a DB-Wax capillary column, as described in Campos et al. (2003) and identified by comparison with known standards. The most abundant fatty acids were linoleic (C18:2), palmitic (C16:0), oleic (C18:1), linolenic (C18:3) and stearic (C18:0). Fe and Zn accumulation occurred as well as changes in some fatty acids and unsaturation level.