Light Spectrum Effects on the Ions, and Primary and Secondary Metabolites of Red Beets (Beta vulgaris L.)

Red beet (Beta vulgaris L.) is a root vegetable consumed and cultivated all around the world. It contains plenty of sugars, inorganic ions and a variety of secondary metabolites known to improve human health. The aim of this work was to investigate the effect of light spectra on red beets and their components in a vertical farm (VF) compared to open field (OF). RED (red:blue-white = 4:1)-treated shoots elevated total phenolic contents (TPC) among lights. Sugar content in VF red beets was 4.2 times higher than beets from OF. Betalains in VF red beets were 2.4–2.8 times higher than OF ones, and RED-treated roots had significantly higher betalain levels compared to CON (red:blue-white = 2:1)-treated ones. VF red beets contained a higher level of inorganic nitrates and lower chloride compared to OF beets. In conclusion, the light spectrum alters the concentration of beet components to be higher than that of OF red beets, and RED light elevated TPC, sugars and betalains.