Increase in the selenium content of extra virgin olive oil: quantitative and qualitative implications

The biofortification of food crops for human consumption is a direct strategy increasing dietary intake of selenium (Se). The aim of this study was to evaluate the possibility of increasing the Se content of extra virgin olive oil (EVOO) by spraying the olive tree canopy with sodium selenate and the effect of the increase in Se on the chemical properties and sensory characteristics of the EVOO. Se treatments were up to 50 times more effective in enhancing Se content in the EVOO compared with the untreated controls. Se concentration in all the EVOO samples can be considered adequate and useful for providing the human diet with the correct dose of Se. Se-enriched EVOO showed a significant increase in pigment and phenol content. Also, Se treatment does not produce negative effects on fruit characteristics or the sensory quality of EVOO.La biofortificación de cultivos alimenticios para el consumo humano es una estrategia directa para aumentar la ingesta de selenio (Se) en la dieta. El objetivo de este estudio fue evaluar la posibilidad de aumentar el contenido de Se en aceites de oliva virgen extra (AOVE) pulverizando la copa de los olivos con selenato de sodio y el efecto del aumento en el contenido de Se en las propiedades químicas y características sensoriales del AOVE. Los tratamientos con Se fueron muy eficaces consiguiendo aumentar el contenido de Se en el AOVE hasta 50 veces más en comparación con los controles no tratados. La concentración de Se en todas las muestras EVOO puede considerarse adecuada y útil para proporcionar a la dieta humana con la dosis correcta de Se. EVOO-Se enriquecido mostró un aumento significativo en pigmentos y contenido de fenoles. Además, el tratamiento de Se no implica efectos negativos sobre caracteristicas frutales ni sobre la calidad sensorial de AOVE

In vitro evaluation of the inhibitory activity of different selenium chemical forms on the growth of a fusarium proliferatum strain isolated from rice seedlings

In this study, the in vitro effects of different Se concentrations (5, 10, 15, 20, and 100 mg kg−1) from different Se forms (sodium selenite, sodium selenate, selenomethionine, and selenocystine) on the development of a Fusarium proliferatum strain isolated from rice were investigated. A concentration‐dependent effect was detected. Se reduced fungal growth starting from 10 mg kg−1 and increasing the concentration (15, 20, and 100 mg kg−1 ) enhanced the inhibitory effect. Se bioactivity was also chemical form dependent. Selenocystine was found to be the most effective at the lowest concentration (5 mg kg−1 ). Complete growth inhibition was observed at 20 mg kg−1 of Se from selenite, selenomethionine, and selenocystine. Se speciation analysis revealed that fungus was able to change the Se speciation when the lowest Se concentration was applied. Scanning Electron Microscopy showed an alteration of the fungal morphology induced by Se. Considering that the inorganic forms have a higher solubility in water and are cheaper than organic forms, 20 mg kg−1 of Se from selenite can be suggested as the best combination suitable to inhibit F. proliferatum strain. The addition of low concentrations of Se from selenite to conventional fungicides may be a promising alternative approach for the control of Fusarium species

Increase in the selenium content of extra virgin olive oil: quantitative and qualitative implications

The biofortification of food crops for human consumption is a direct strategy increasing dietary intake of selenium (Se). The aim of this study was to evaluate the possibility of increasing the Se content of extra virgin olive oil (EVOO) by spraying the olive tree canopy with sodium selenate and the effect of the increase in Se on the chemical properties and sensory characteristics of the EVOO. Se treatments were up to 50 times more effective in enhancing Se content in the EVOO compared with the untreated controls. Se concentration in all the EVOO samples can be considered adequate and useful for providing the human diet with the correct dose of Se. Se-enriched EVOO showed a significant increase in pigment and phenol content. Also, Se treatment does not produce negative effects on fruit characteristics or the sensory quality of EVOO.<br><br>La biofortificación de cultivos alimenticios para el consumo humano es una estrategia directa para aumentar la ingesta de selenio (Se) en la dieta. El objetivo de este estudio fue evaluar la posibilidad de aumentar el contenido de Se en aceites de oliva virgen extra (AOVE) pulverizando la copa de los olivos con selenato de sodio y el efecto del aumento en el contenido de Se en las propiedades químicas y características sensoriales del AOVE. Los tratamientos con Se fueron muy eficaces consiguiendo aumentar el contenido de Se en el AOVE hasta 50 veces más en comparación con los controles no tratados. La concentración de Se en todas las muestras EVOO puede considerarse adecuada y útil para proporcionar a la dieta humana con la dosis correcta de Se. EVOO-Se enriquecido mostró un aumento significativo en pigmentos y contenido de fenoles. Además, el tratamiento de Se no implica efectos negativos sobre caracteristicas frutales ni sobre la calidad sensorial de AOVE

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

Effect of Acinetobacter sp on Metalaxyl Degradation and Metabolite Profile of Potato Seedlings (Solanum tuberosum L.) Alpha Variety

One of the most serious diseases in potato cultivars is caused by the pathogen Phytophthora infestans, which affects leaves, stems and tubers. Metalaxyl is a fungicide that protects potato plants from Phytophthora infestans. In Mexico, farmers apply metalaxyl 35 times during the cycle of potato production and the last application is typically 15 days before harvest. There are no records related to the presence of metalaxyl in potato tubers in Mexico. In the present study, we evaluated the effect of Acinetobacter sp on metalaxyl degradation in potato seedlings. The effect of bacteria and metalaxyl on the growth of potato seedlings was also evaluated. A metabolite profile analysis was conducted to determine potential molecular biomarkers produced by potato seedlings in the presence of Acinetobacter sp and metalaxyl. Metalaxyl did not affect the growth of potato seedlings. However, Acinetobacter sp strongly affected the growth of inoculated seedlings, as confirmed by plant length and plant fresh weights which were lower in inoculated potato seedlings (40% and 27%, respectively) compared to the controls. Acinetobacter sp also affected root formation. Inoculated potato seedlings showed a decrease in root formation compared to the controls. LC-MS/MS analysis of metalaxyl residues in potato seedlings suggests that Acinetobacter sp did not degrade metalaxyl. GC–TOF–MS platform was used in metabolic profiling studies. Statistical data analysis and metabolic pathway analysis allowed suggesting the alteration of metabolic pathways by both Acinetobacter sp infection and metalaxyl treatment. Several hundred metabolites were detected, 137 metabolites were identified and 15 metabolic markers were suggested based on statistical change significance found with PLS-DA analysis. These results are important for better understanding the interactions of putative endophytic bacteria and pesticides on plants and their possible effects on plant metabolism

Fate of selenium in soil: A case study in a maize (Zea mays L.) field under two irrigation regimes and fertilized with sodium selenite

Selenium (Se) is a trace element necessary for both human and livestock nutrition. To increase Se human intake, soil Se fertilizations were performed but the fate of the added Se remains unclear. The present research aims to: (1) determine the influence of Se fertilization on the fractionation of Se in soil; (2) assess the influence of water availability on the distribution of soil Se chemical fractions; and (3) monitor the Se content in soil, leachates and plants. To reach these goals, 200 g Se ha−1 was applied to soil as sodium selenite in maize crops under two irrigation regimes, and the Se content in plant, soil chemical fractions and leachates were analyzed. Se application increased the total Se content of the soil, specifically it increased the Se content of the soluble, exchangeable and organic fractions with more pronounced effect in the soils with higher water availability. These differences disappeared over time likely due to the Se loss through volatilization. The hypothesis of Se volatilization is confirmed by the absence of both leachates during the maize growing season and differences among the treatments of Se content in sub-soil samples. Also, although the Se treated plants showed higher Se content than the untreated ones, overall 1% of the added Se was assimilated by plants. Hence, this study demonstrated that the addition of selenite to the soil increased the Se contents of the plants, but the Se does not accumulate in the soil because it is likely lost via volatilization. Further, leaching of Se into groundwater is avoided due to its association with both the soil organic matter and positively charged binding sites of soil, and due to its loss via volatilization. Therefore, soil Se fertilization could increase the nutritional value of plants without consequences on the environment