AGRONOMIC SELENIUM BIOFOTIFICATION OF GRAPES AND SANGIOVESE WINE

Selenium (Se) is an element found in the soil, and it naturally appears in water and some foods. Se plays a key role in the metabolism. It is mainly involved in the production of the active thyroid hormone, in muscle function, in the reproduction process and in the immune response to some infections. One of the most promising approaches to combat a low transfer of Se from soil into the food chain involves a concept called Se biofortification. This agronomic-based strategy can be utilized by farmers to produce Se-enriched food products that may help reduce dietary deficiencies of Se occurring throughout susceptible regions of the world. An effective method of biofortifying food crops with Se is foliar application. 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 Sangiovese vines in the pre-flowering period with sodium selenate (100 mg Se L-1). Se content was measured in leaves, fruit at harvest time and in wine respectively in treated and not treated samples with Octopole Reaction System ICP MS (Agilent 7900). At harvest, a higher amount of Se in the treated leaves compared to untreated ones was found, 16 ± 3.13 mg kg-1 against 0.17 ± 0.06 mg kg-1 in the untreated ones. The treated grape had a content of Se of 0.800 ± 0.08 mg kg-1, while that untreated one 0.065 ± 0.02 mg kg-1. Immediately after the malolactic fermentation, the wine obtained from treated and untreated vines had a Se content of 0.620 ± 0.09 mg Se kg-1 and 0.139 ± 0.01 mg Se kg-1 respectively. Even if people only need a very small amount and a recommended dietary allowance (RDA) of 50-70 μg Se day-1 has been established for regular adults. Assuming a daily wine consumption of 50 mL, the contribution to the daily Se RDA is remarkable since it is 44 and 88 % for adult men and women, respectively.