Effect of postharvest UV-B and UV-C radiation on the bioactive quality of broccoli and radish sprouts

Abstract

Radish and broccoli are very rich in bioactive compounds, especially in their early growth stages after germination. Therefore, the objective of this work was to increase the functional properties of their 10-day sprouts at 20 ℃, by applying ultraviolet radiation-UV-(9 kJ/m2 UV-C or 15 kJ/m2 UV-B) as a post-harvest abiotic stress. A shelf life of 10 days at 4 ℃ was studied in a commercial package. UV-B radiation increased the total antioxidant capacity and total phenolic compounds of both sprouts by up to 20%, compare to the control without UV. Radish sprouts showed a high content of sulforaphane, an anticarcinogenic compound whose biosynthesis was stimulated after UV-B and C stresses, by up to 47% compared to the control. This behavior was not observed in broccoli sprouts. In conclusion, the functionality of these sprouts was enhanced mainly after UV-B stresses, and was maintained throughout their shelf life. We consider that UV-B radiation is an effective technology for the stimulation of bioactive compounds with antioxidant and anticarcinogenic properties, for the benefit of consumers demanding a healthy and balanced diet.