Effect of Light Quality on Secondary Metabolite Production in Leafy Greens and Seedlings
It has been experimentally found that light stimulation significantly enhances the production of specific biomolecules in plants. The biosynthetic products mentioned herein are secondary metabolites, which are organic compounds that do not participate directly in cell growth or division; these include antioxidants, vitamins, sugars, and pigments. Several studies have investigated antioxidants in a variety of plants such as leaf lettuce, microgreen, sprout, and cherry tomatoes, and they have reported that the biosynthesis of chlorogenic acid, caffeic acid, chicory acid, flavonoids, rosmarinic acid, ascorbic acid, and carotenoids, along with antioxidant activity and DPPH radical scavenging capacity, is promoted by stimulating with light of a specific wavelength. It has been also reported that ascorbic acid, carotenoids, a tocopherol, and ergosterol for antioxidants; sucrose, fructose, and glucose for sugars; and anthocyanin and chlorophyll for pigments are enhanced by light stimulus. Although the mechanism underlying the increase in the synthesis of these molecules by light stimulus remains unclear, the use of this technique is possible if reproducibility is ensured.