2019 ASHS Annual Conference

Selenium (Se) biofortification of edible plants has been suggested as a method of increasing dietary Se intake. Popular culinary herbs such as scallions (Allium fistulosum), basil (Ocimum basilicum), and cilantro (Coriandrum sativum) are used for enhancing flavors of meals and present an opportunity as a small dietary addition for achieving supra-adequate Se intake. Microgreens are young seedlings harvested with or without one to two true leaves and are increasingly popular in the consumer marketplace. In this study, scallion, basil, and cilantro microgreens were treated with 0.0, 2.5, and 5.0 mg·L^-1 of Se as sodium selenate in the hydroponic nutrient solution. Scallions, as an Allium species and accumulator of Se, were treated with an additional dose of 10.0 mg·L^-1 of Se. The effect of biofortification on plant yield, mineral content (selenium, sulfur, sodium, potassium, phosphorus, calcium, magnesium, copper, iron, manganese, zinc, and boron), total phenolic compounds, and antioxidant capacity were assessed on a fresh weight basis. Results showed all three culinary herbs increased Se content with increasing Se concentrations in the nutrient solution. The highest levels of treatment increased Se content by 507, 155, and 40 times for scallions, basil, and cilantro, respectively. At 10.0 mg·L^-1 of Se, scallions demonstrated increases in all minerals analyzed, total phenolic compounds (113.7%), and total antioxidant capacity (152.2%), but plant yield decreased by 68.0%. At the highest treatment for basil and cilantro, 5.0 mg·L^-1 of Se, basil increased potassium, phosphorus, sulfur, total phenolic compounds (102.6%), and antioxidant capacity (68.6%), but decreased plant yield by 35.5%. Cilantro demonstrated an increase in sodium, total phenolic compounds (50.3%), and antioxidant capacity (66.0%) without an effect on plant yield. Overall, results showed sodium selenate biofortification can be used to enhance the content of Se, other minerals relevant to human health, and antioxidants in culinary herb microgreens. Nutritionally, scallions at 10.0 mg·L^-1 of Se can offer the highest source of Se with the added benefits of increases in other minerals and antioxidants. Further, promotion of Se-biofortified culinary herbs as a functional food can enable growers to offset the loss of plant yield with higher economic returns.