Determination of speciation of the micronutrient selenium in milk and blood of lactating cows by spectroscopic techniques with synchrotron radiation

• Grant number: 23/14182-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: February 01, 2024
• End date: January 31, 2026
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal Investigator: Arlindo Saran Netto
• Grantee: Vanessa Isabel Tardillo Suarez
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil
• Associated research grant: 21/07131-0 - Biofortification of milk with selenium: effect on nutritional bioavailability and action on human health, AP.TEM

Abstract

Selenium (Se) is essential for human metabolism and exerts biological activity through its incorporation into proteins, forming selenoproteins, which perform an antioxidant activity capable of reducing peroxides in the human body (Rayman, 2002). Furthermore, anticancer activity of some forms of Se in colon, lung, skin and other types of cancer has been demonstrated. Therefore, samples of milk, blood, and other tissues will be prepared and provided by those responsible for the first project, which involves the supplementation of lactating cows, and the second project, which involves the use of biofortified milk in mice, both of which are part of the thematic project. From these materials, the identification and quantification of different chemical species of selenium in samples of biofortified milk will be carried out, which will imply the standardization of analysis methods by spectroscopic techniques with synchrotron light using the light lines of the new Sirius ring of the National Synchrotron Light Laboratory ( LNLS/CNPEM). In a first step, studies will be carried out to identify and quantify the relative presence of selenium in the samples, comparing with well-known selenium composition patterns, through X-ray Fluorescence Spectrometry. same sample and reference materials containing selenium at known concentrations.In the sequence, studies of the different chemical species present will be carried out, through X-ray Absorption Spectroscopy. EXAFS, very precisely quantify the chemical state of the element selenium in its various oxidation states, and can even indicate which complexes are being formed.