Effects of LED Light Quality on Broccoli Microgreens Plant Growth and Nutrient Accumulation

Broccoli microgreens represent a novel type of vegetable characterized by high levels of bioactive compounds. Here, we investigated the effects of light-emitting diode (LED) light quality on the development and nutritional uptake of broccoli microgreens. The plants were exposed to five distinct light treatments: white, single red, and red: blue at 5:1, 5:3, and 5:5 ratios. The soluble sugars, nutrients, and secondary metabolites of broccoli sprout extracts were examined using high-performance liquid chromatography and ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry under various light-quality conditions. In addition, the expression levels of genes encoding important enzymes in the glucosinolates (GLs) biosynthesis pathway were examined using quantitative real-time polymerase chain reaction. Overall, the findings demonstrated that mixed red-blue light, especially the 5:1 red: blue ratio, was beneficial for broccoli microgreens in terms of their hypocotyl length, fresh weight, edible rate, soluble proteins, vitamin C, total phenolics, total flavonoids, and GLs. Our findings provide a foundation and reference point for selecting the most appropriate LED light ratio in microgreens production.