Postharvest UV-B and Visible LED Lighting Preserve Quality and Modulate Bioactive Compounds in Strawberries

Abstract Strawberries are a highly appreciated perishable commodity, with a very short shelf life due to fungal development, dehydration, and softening. The main objective was to evaluate the effect of a postharvest UV-B treatment (10 kJ/m 2 ) and a visible spectrum LED illumination (full white, blue, green, and red) during 13 days at 3.3 °C on the main physicochemical and sensory quality attributes of strawberries, fungal development, and changes in their main bioactive compounds (total phenolic content (TPC), total antioxidant capacity (TAC), and anthocyanin content). No UV-B treatment and darkness storage was used as control. UV-B combined with visible LED lighting did not report significant effect on decay reduction. However, when combined with green and red LEDs, softening was accelerated, although firmness after 13 days remained above the commercial threshold (firmness reductions of 32.7 and 23% compared to initial day, respectively). The strawberries stored under full white, blue, green, and red illumination showed higher TPC compared to darkness (19.7, 14.6, 17.0, and 16.6%, respectively). The combination of UV-B and LED illumination during storage reported a TPC cumulative increase, especially under red light (35.2%), suggesting a synergistic activation of light-responsive metabolic pathways. This effect was not observed for TAC, where a UV-B treatment by itself reported an 80.4% increase, while the illumination during storage did not result in a synergistic effect. Anthocyanins did not report significant accumulation, indicating a limited response of this pathway to postharvest light stimuli. Further studies should elucidate the underlying molecular mechanisms by which UV-B and visible light modulate quality attributes and defense responses in strawberries. Graphical Abstract