Biofortification of Arugula Microgreens Through Supplemental Blue Light

Eruca sativa has been widely chosen among species to be cultivated in plant factories as microgreens, especially due to its nutraceutical and sensory qualities. Thus, the objective of this study was to evaluate the impact of blue light intensity (5 and 20 μmol m−2 s−1) and exposure time (1 and 2 h per day) on the yield and quality of arugula microgreens in plant factories. Blue light supplemental to white light for 1 h did not impair the hypocotyl lengths (HLs) or cotyledon area (CA) and yield of arugula microgreens compared with those grown only with white light. However, when the blue light time increased from 1 to 2 h, there were reductions in HL, CA and yield, with greater reductions under 20 μmol m−2 s−1. The concentrations of chlorophylls, carotenoids, vitamin C and antioxidant power responded similarly to the supply of blue light and were maximized with 20 μmol m−2 s−1. In view of these results, the supplementation of blue light with 20 μmol m−2 s−1 for 1 h is proposed, since it did not cause a reduction in growth and yield parameters and promoted the agronomic biofortification of arugula microgreens, bringing nutraceutical and, therefore, commercial benefits to the producer and consumer.