Maria Chiara Fontanella

Selenium speciation profiles in biofortified sangiovese wine.

Biofortification is an agronomic-based strategy, utilized by farmers, to produce selenium (Se)-enriched food products that may help reduce dietary deficiencies of Se occurring throughout susceptible regions of the world. The foliar exposure route application ensures a high efficiency of Se assimilation by the plant since it does not depend on root-to-shoot translocation. In this study we treated grapevines of Sangiovese variety in the pre-flowering period with sodium selenate (100mg Se L-1). Se content was measured in leaves, fruit at harvest time and in wine respectively in treated and not treated samples with ICP-MS. At harvest, a higher amount of Se in the treated leaves compared to untreated ones was found, 16.0±3.1mgkg-1 dry weight (dw) against 0.17±0.006mgkg-1 dw in the untreated ones. The treated grapes had a content of Se of 0.800±0.08mgkg-1 dw, while that untreated one 0.065±0.025mgkg-1 dw. Immediately after the malolactic fermentation, the wine obtained from treated and untreated vines had a Se content of 0.620±0.09mg Se L-1 and 0.024±0.010mg Se L-1 respectively. In our case the percentage of inorganic Se is 26% of the total Se in the untreated wine, while in Se enriched wine this percentage increase to 47.5% of the total Se. The Se(VI) was the inorganic chemical form more present in enriched wine, probably due to foliar application with selenate. Distributions of Se species suggested being careful to the choice of the enrichment solutions to promote a balanced distribution of different chemical forms, perhaps favouring the accumulation of organic forms.

Total As and As Speciation in Italian Rice as Related to Producing Areas and Paddy Soils Properties

Rice and rice-based foodstuffs are important pathways for inorganic As dietary intake. This work shows a detailed picture of As content and speciation in Italian rice, which contributes to more than one-half of the European production, and addresses the role of soil chemistry and agronomic management on As concentration in rice grain, in view of ameliorative strategies. The mean total As content in Italian white rice was 155 ± 65 μg kg-1 with significant differences among producing areas, while the mean inorganic As was 102 ± 26 μg kg-1, largely below the E.U. limit of 200 μg kg-1 for white rice, although part of the production would not be suitable for baby food production, which requires less than 100 μg kg-1 of inorganic As. The differences in As content and speciation in rice among the studied areas resulted from the complex interactions of soil, plant, and anthropic factors. Among others, Si nutrition seemed to play a key role in regulating As transfer from soil to plant.

Soil Selenium (Se) Biofortification Changes the Physiological, Biochemical and Epigenetic Responses to Water Stress in Zea mays L. by Inducing a Higher Drought Tolerance

Requiring water and minerals to grow and to develop its organs, Maize (Zea mays L.) production and distribution is highly rainfall-dependent. Current global climatic changes reveal irregular rainfall patterns and this could represent for maize a stressing condition resulting in yield and productivity loss around the world. It is well known that low water availability leads the plant to adopt a number of metabolic alterations to overcome stress or reduce its effects. In this regard, selenium (Se), a trace element, can help reduce water damage caused by the overproduction of reactive oxygen species (ROS). Here we report the effects of exogenous Se supply on physiological and biochemical processes that may influence yield and quality of maize under drought stress conditions. Plants were grown in soil fertilized by adding 150 mg of Se (sodium selenite). We verified the effects of drought stress and Se treatment. Selenium biofortification proved more beneficial for maize plants when supplied at higher Se concentrations. The increase in proline, K concentrations and nitrogen metabolism in aerial parts of plants grown in Se-rich substrates, seems to prove that Se-biofortification increased plant resistance to water shortage conditions. Moreover, the increase of SeMeSeCys and SeCys2 forms in roots and aerial parts of Se-treated plants suggest resistance strategies to Se similar to those existing in Se-hyperaccumulator species. In addition, epigenetic changes in DNA methylation due to water stress and Se treatment were also investigated using methylation sensitive amplified polymorphism (MSAP). Results suggest that Se may be an activator of particular classes of genes that are involved in tolerance to abiotic stresses. In particular, PSY (phytoene synthase) gene, essential for maintaining leaf carotenoid contents, SDH (sorbitol dehydrogenase), whose activity regulates the level of important osmolytes during drought stress and ADH (alcohol dehydrogenase), whose activity plays a central role in biochemical adaptation to environmental stress. In conclusion, Se-biofortification could help maize plants to cope with drought stress conditions, by inducing a higher drought tolerance.

Use of Selenium-enriched olive leaves in the feed of growing rabbits: Effect on oxidative status, mineral profile and Selenium speciation of Longissimus dorsi meat

In the present study the use of Selenium-fortified olive leaves as potential dietary source of Se in rabbit nutrition was evaluated. Sixty New Zealand White rabbits (35 days of age) were randomly assigned to the following dietary treatments: standard diet (C), and C supplemented with either 10% olive leaves (OL) or 10% Selenium-fortified olive leaves (SeOL; 100 mg/L of foliar spray sodium selenate solution). At 70 days of age, 10 rabbits per group were slaughtered and the oxidative status, mineral profile and Selenium speciation of Longissimus dorsi meat was analyzed. Meat of the SeOL group exhibited better oxidative status (lower TBARS, higher GPx and α-tocopherol values) and a 5-fold higher Se content compared to that of the other treatments. The main Se form was SeMet (7-fold higher in the SeOL group), followed by SeCys2. The present trial demonstrates the possibility of using agro-industrial by-products as ingredients in rabbit feeds, thereby enriching meat bioactive compound content.

Selenium Biofortification in Rice (Oryza sativa L.) Sprouting: Effects on Se Yield and Nutritional Traits with Focus on Phenolic Acid Profile

The contents of total Se and of inorganic and organic Se species, as well as the contents of proteins, chlorophylls, carotenoids, and phenolic acids, were measured in 10-day old sprouts of rice ( Oryza sativa L.) obtained with increasing levels (15, 45, 135, and 405 mg Se L-1) of sodium selenite and sodium selenate and with distilled water as control. Increasing Se levels increased organic and inorganic Se contents of sprouts, as well as the content of phenolic acids, especially in their soluble conjugated forms. Moderate levels of sodium selenite (i.e., not higher that 45 mg L-1) appeared the best compromise to obtain high Se and phenolic acid yields together with high proportion of organic Se while limiting residual Se in the germination substrate waste. Se biofortification of rice sprouts appears a feasible and efficient way to promote Se and phenolic acid intake in human diet, with well-known health benefits.

Determination of Sb(III) and Sb(V) by HPLC-Online isotopic dilution-ICP MS.

Graphical abstract