Selenium Biofortification of <i>Solanum</i> Vegetables Modulates Their Phytoconstituents, Agronomic and Antioxidant Properties

ABSTRACT Selenium biofortification of food crops is a method of ameliorating selenium deficiency in a population. Considering the reported relatively low selenium level in the Nigerian soil, there is hence the need to boost selenium through dietary means. The aim of this study is to assess the ability of the African eggplant ( Solanum macrocarpon L.) and black nightshade ( Solanum nigrum L.) to bioaccumulate selenium in their leaves. These vegetables were cultivated on soil fortified with selenium and the leaves were harvested at maturity. The mineral composition was determined via inductively coupled plasma optical emission spectroscopy. Total phenol and flavonoid contents, and in vitro antioxidant properties such as 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid) and 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging abilities of the vegetables were assessed. Results show that both leaf samples bioaccumulate selenium, leading to 20% increase in Se concentration (African eggplant from 5.91 ± 0.02 mg/100 g to 101.01 ± 0.05 mg/100 g; black nightshade from 5.41 ± 0.05 to 124. 63 ± 0.02 mg/100 g). Selenium bioaccumulation also led to an increase in concentration of some phytochemicals in the leaves, as well as in vitro antioxidant properties. The results indicate that Selenium biofortification optimally influences mineral concentration, phytochemical composition, and in vitro antioxidant properties of the African eggplant and black nightshade leaves.