Differential Effects of Low Light Intensity on Broccoli Microgreens Growth and Phytochemicals

To produce high-quality broccoli microgreens, suitable light intensity for growth and phytochemical contents of broccoli microgreens in an artificial light plant factory were studied. Broccoli microgreens were irradiated under different photosynthetic photon flux density (PPFD): 30, 50, 70 and 90 mu mol.m(-2).s(-1) with red: green: blue = 1:1:1 light-emitting diodes (LEDs). The broccoli microgreens grown under 50 mu mol.m(-2).s(-1) had the highest fresh weight, dry weight, and moisture content, while the phytochemical contents were the lowest. With increasing light intensity, the chlorophyll content increased, whereas the carotenoid content decreased. The contents of soluble protein, soluble sugar, free amino acid, flavonoid, vitamin C, and glucosinolates except for progoitrin in broccoli microgreens were higher under 70 mu mol.m(-2).s(-1). Overall, 50 mu mol.m(-2).s(-1) was the optimal light intensity for enhancement of growth of broccoli microgreens, while 70 mu mol.m(-2).s(-1) was more feasible for improving the phytochemicals of broccoli microgreens in an artificial light plant factory.

Automated summary

Through studying the effects of different light intensities on the growth and phytochemical content of broccoli microgreens, it was found that 50 μmol.m^(-2).s^(-1) was the optimal light intensity for enhancing the growth of broccoli microgreens, while 70 μmol.m^(-2).s^(-1) was more favorable for improving the phytochemicals in an artificial light plant factory.