Effect of Agronomical and Technological Treatments to Obtain Selenium-Fortified Table Olives

The biofortification of food crops for human consumption is a direct strategy for increasing dietary intake of selenium (Se). The aims of this study were the evaluation of different Se-fortification variables (concentration and number of foliar applications) for obtainment of fortified olives and the efficacy of two technological treatments (brining and dehydration) applied to them in the maintenance of this element. The research was carried out in two experiments: the results of first one were that the application of the highest Se concentration (75 mL L−1) on olive trees was useful to obtain fortified Gordal olives (650 µg kg−1) but the further brining process did not allow an acceptable retention of this nutrient in olive pulp for its dissolution in brines: the decrease was from 92 to 99%. The second experiment concerned in different number of foliar applications of the best previously tested Se-solution (75 mL·L−1) to obtain fortified Carolea olives, that were then submitted to different drying processes to became edible. The available selenium in the final products was better retained in olives dried without any preliminary treatment prior to drying and in those pre-treated by dried salt, with different trends linked to foliar application number.