UV abiotic stresses have beneficial effects in plants inducing the synthesis of secondary metabolites when low doses were applied. The aim of this study was to evaluate the effect of 6 kJ m−2 UV (B or C) and 6 + 6 kJ m−2 UV (B + C) on the main bioactive compounds of red bell peppers during a refrigerated shelf-life period. Changes in carotenoids, phenolics, and flavonoids were studied after 8 and 14 d at 7 °C, an after an additional retail sale period of 4 d at 18 °C. Physicochemical quality attributes were not affected by any UV treatment. Generally, UV treatments induced carotenoid accumulation, highlighting that after 14 d at 7 °C, UVB and UVC increased by 59 % the total carotenoid content, and UVB + C did it by 94 % compared to non-UV-treated peppers as control (CTRL). UVC, UVB, and UVB + C are good elicitors of the flavonoid biosynthesis with 42, 66, and 43 % increases just after treatment, respectively, compared to CTRL. This behaviour was enhanced in UVC and UVB + C treated peppers after 8 d at 7 °C (15 and 44 %, respectively) and after 14 d at 7 °C (146 and 137 %) regarding CTRL peppers, which was also shown after the retail period assayed of 4 d at 18 °C. In conclusion, a postharvest 6 kJ m-2 UV-C treatment could be a great tool for increasing the accumulation of carotenoids and flavonoids in red bell peppers.This research received no external funding.
Noelia Castillejo contract was funded by a predoctoral grant (FPU16/04763) from the Spanish Ministry of Education. Lorena Martínez-Zamora contract has been co-financed by the European Social Fund and the Youth European Initiative under the Spanish Seneca Foundation (21322/PDGI/19). Authors thanks Henarejos y Tárraga, S.L. and the Asociación Eco-innovadora Agrícola de la Región de Murcia for the kindly supply of bell peppers
