The Influence of Light Wavelength on Resveratrol Content and Antioxidant Capacity in Arachis hypogaeas L.

The quality and intensity of light can have a huge influence on plant growth and bioactive compound production. Compared to conventional lighting, very little is known about the influence of light emitting diodes (LED) irradiation on the antioxidant and antimicrobial properties and resveratrol content of peanut sprouts. This study was aimed at understanding the effects of LED light on the growth and antioxidant capacity of peanut sprouts. The resveratrol concentration was determined by liquid chromatography–tandem mass spectrometry. Peanut sprouts grown under blue LED light exhibited a higher total resveratrol content grown than those under fluorescent light and other LED light sources. The highest total phenolic content was recorded in the case of blue LED. The 1,1-diphenyl-2-picrylhydrazyl and 2,2-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid radical scavenging values of blue LED‒treated and micro-electrodeless light-treated sprouts were significantly (p < 0.05) higher than that of sprouts grown under lights with other wavelengths. A Pearson correlation analysis revealed a strong association of the resveratrol, total phenolic, and flavonoid contents of peanut sprouts with 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS), indicating its contribution to antioxidant activities. The anti-tyrosinase activity increased with an increase in the concentration of the tested sample. Blue LED-irradiated peanut extracts at a selected concentration range showed moderate cytotoxicity. Furthermore, the antimicrobial activity of peanut sprouts grown under blue LED was effective against Escherichia coli, Klebsiella pneumonia, and Vibrio litoralis. The present study revealed that the application of LEDs during the peanut sprouts growth improves the antioxidant activity, resveratrol concentration, and metabolite accumulation.