A photoperiod including visible spectrum LEDs increased sulforaphane in fresh-cut broccoli

The objective was to elucidate if a photoperiod including fluorescent light (14 h) and visible spectrum LEDs (10 h), during night periods, can increase the phytochemical content in fresh-cut broccoli while not affecting other quality attributes. Monochromatic LEDs used were Cool White-CW-, Blue-B-, Green-G-, Red-R-, and Far-Red-FR-, while darkness was used as control. Changes in weight losses, colour, epiphytic microorganisms, and main bioactive compounds (glucosinolates and isothiocyanates) were assessed during 16 days at 5 degrees C. Illumi-nation with G and R lights accelerated yellowing of florets after 14 days. Higher weight losses were registered for LEDs treatments regarding darkness while no changes were observed for microbial development among treat-ments. All studied photoperiods including LEDs enhanced the sulforaphane content regarding darkness, espe-cially after 7 days, reporting CW, B, and FR treatments increases over 40%. However, the glucosinolate content and myrosinase activity were not stimulated by LEDs. In conclusion, a supplementation with CW, B, or FR LEDs during night periods at retail sale seems a strategy to enhance the sulforaphane accumulation in Brassicaceae. Probably, higher and / or other stresses can be applied to increase / activate the synthesis and accumulation of more secondary metabolites.

Automated summary

The study aimed to determine if using a photoperiod with fluorescent light and visible spectrum LEDs during night periods can increase the phytochemical content in fresh-cut broccoli without affecting other quality attributes.