Metabolomics and Molecular Networking Approach for Exploring the Effect of Light Intensity and Quality on the Chemical Profile and Accumulation of Glucosinolates in Broccoli Microgreen

Light intensity is a crucial factor impacting the cost-efficiency of controlled environment agriculture (CEA). Broccoli microgreens were cultivated under different photosynthetic photon flux densities: 50, 100, and 150 μmol•m^-2•s^-1 with white light-emitting diodes (LEDs), and an additional far-red (FR) light supplement (20% of total photon flux density) at the 50 μmol•m^-2•s^-1 intensity. This study examines how low light intensity influences the chemical profile and glucosinolate accumulation in broccoli microgreens through both nontargeted and targeted metabolomics with molecular networking analysis. The analysis identified 28 glucosinolates and 23 phenolic compounds with targeted quantification of 12 glucosinolates. The results showed that FR light supplementation significantly increased the total glucosinolate content compared to white light-only treatments, while similar glucosinolate levels were found across the different white light intensities. These findings provide valuable insights for optimizing LED light intensity to enhance glucosinolate accumulation in broccoli microgreens, thus promoting more efficient energy use in CEA.