Basil seeds as a source of antioxidants affected by fortification with selenium

The work aimed to determine the potential of selenium incorporation into seeds of selected species of Ocimum spp. after fortification with a foliar solution of sodium selenate at a concentration of 50 g Se · ha⁻¹. In a 2-year trial, the selenium content was determined by electrothermal atomic absorption method with Zeeman background correction. Modified spectrophotometric method (2,2-diphenyl-1-picrylhydrazyl [DPPH] assays) was used to rate the potential of oxidation– reduction components of basil seeds (AA). The total polyphenol content (TPC) was determined spectrophotometrically using the Folin–Ciocalteu reagent and gallic acid (GA) as the standard solution. The results of experiments showed that the selenium biofortification significantly (p < 0.05) increased the content of selenium in basil seeds (17-fold increase in comparison with controlled variant in case of Tulsi, 12-fold in ‘Cinamonette’ and 12-fold in ‘Dark Green’ when compared with control). The basil seeds represented a valuable source of polyphenols (1414.61–1681.75 μg GA · g⁻¹ dried weight [d.w.]) with multiple times higher antioxidant activity (23.50–28.97 mmol Trolox · kg⁻¹) in comparison with common tested horticultural crops (e.g. peas, tomato and pumpkin). Significant influence of fortification was not found in AA and TPC values. Fortification was not significantly reflected in AA and TPC values. In addition to its very strong reproductive function, healing and religious purposes, the basil seed is used as a functional food due to its high content of bioactive compounds.