Maria J. Poblaciones

Agronomic selenium biofortification in Triticum durum under Mediterranean conditions: From grain to cooked pasta

To improve the nutritional value of durum wheat and derived products, two foliar Se fertilisers (sodium selenate and selenite) were tested at four rates (0-10-20-40gha(-1)) in 2010/2011 and 2011/2012 in southwestern Spain. There was a strong and linear relationship between total Se or selenomethionine (Se-Met) accumulation in grain and Se dose for both fertilisers, although selenate was much more efficient. Se-Met was the main Se species (≈90%) of the total Se extracted from all materials. Milling caused a 27% loss of Se due to the removal of Se located in bran and germ. In the pasta making process and the cooking process the loss of Se, mainly as selenite, was about 7%. Durum wheat may be a good candidate to be included in Se biofortification programs under rainfed Mediterranean conditions, as foodstuffs derived from it could efficiently increase the Se content in the human diet.

Selenium Speciation in Malt, Wort, and Beer Made from Selenium-Biofortified Two-Rowed Barley Grain

Selenium (Se) biofortification of barley is a suitable strategy to increase the Se concentration in grain. In the present paper, the suitability of this Se-biofortified grain for making Se-enriched beer is analyzed. The aim of the present study was to evaluate the effect of different Se fertilizer doses (0, 10, and 20 g of Se ha(-1)) and forms (sodium selenate or sodium selenite) on the Se loss during the malting and brewing processes and Se speciation in grain, malt, wort, and beer. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) and high-performance liquid chromatography (HPLC)-ICP-MS for total Se and speciation. Mashing-lautering was the process with the greatest Se loss (83.8%). After malting and brewing, only 7.3% of the initial Se was retained in beer, mainly in selenite form. Even so, the fertilizer application of sodium selenate at 20 g ha(-1) increased the total Se concentration almost 6-fold in the final beer in comparison to the use of grain derived from unfertilized barley. The present paper provides evidence that the use of Se-biofortified barley grain as a raw material to produce Se-enriched beer is possible, and the results are comparable to other methods in terms of efficiency.

Selenium biofortification in bread-making wheat under Mediterranean conditions: influence on grain yield and quality parameters

Abstract. The diet of millions of people around the world is deficient in selenium (Se). Bread-making wheat has been successfully used in Se biofortification programs under temperate climate to remedy Se deficiency. However, its suitability under Mediterranean conditions and its effect on the grain yield and quality parameters are not well known. In a wheat field in south-western Spain, two foliar Se fertilisers (sodium selenate and sodium selenite) were applied at four application rates (0, 10, 20, 40 g ha–1) in 2010–11 and 2011–12. Results showed a strong and linear relationship between total Se in grain and Se dose for both fertilisers, although selenate was much more efficient. A dose of 10 g sodium selenate ha–1 was able to increase significantly the Se in grain to close to the recommended values, although Se loss of 28% during the milling process might be expected. Grain yield was not negatively affected by fertilisation, but grain protein and dry gluten were slightly negatively affected, but only in the dry year. Alveograph parameters were either not affected or slightly favoured by Se fertilisation in any studied year. Bread-making wheat is a good candidate to be included in biofortification programs under semi-arid Mediterranean conditions.

Combined zinc and nitrogen fertilization in different bread wheat genotypes grown under mediterranean conditions

The combined application of nitrogen (N) and zinc (Zn) appears to be a promising agronomic strategy for the biofortification with Zn. To evaluate such efficiency, a field experiment was conducted in south-eastern Portugal under Zn-deficient soil. Four advanced breeding lines and two commercial varieties of bread wheat (Triticum aestivum L.) were fertilized with five treatments: i) control, ii) two foliar Zn applications, iii) one foliar Zn+N application, iv) soil and two foliar Zn applications, and v) soil and one foliar Zn+N application. Grain Zn content varied greatly across treatments and INIAV-1 and the commercial varieties were the most interesting cultivars in all the treatments. Grain Zn concentrations higher than the target level of 38 mg Zn kg−1 were obtained only when two foliar Zn applications were applied, alone or in combination with soil Zn applications, and grain Zn bioavailability also was more adequate (phytate:Zn ratios similar to 15). Soil Zn application resulted in grain yield increase...