An abiotic UV-B stress on Brassicaceae seeds increased their phytochemical content on 7-days sprouts

Cruciferous sprouts in their early stages of development are very suitable foods against degenerative diseases due to their high content of health promoting compounds. The application of UV-B can act as an elicitor of these compounds. The objective was to study the effect of a UV-B treatment to different seed varieties and its remnant effects after germination as sprouts.

Brassicaceae seeds selected (radish, rocket, white mustard, and tatsoi) were treated under 20 kJ m-2 UV-B 24 h before sowing, while no UV radiation was used as control (CTRL). After 7 days, sprouts were harvested, frozen, and freeze-dried until their bioactive content was analysed.

Results showed that UV-B enhanced by ~20% the biosynthesis of phenolic compounds in sprouts, and hence, their total antioxidant capacity. Furthermore, this UV effect was also appreciated after 7 germination days, and it was increased by ~38% regarding CTRL, especially on rocket and mustard sprouts. In conclusion, an abiotic UV-B stress treatment to seeds can be an interesting tool to improve the bioactive compounds content of young plants, although the intrinsic mechanisms involved should be further investigated.

Research limitations: 

The use of these new technologies, such as UV-B, is costly and must be applied following appropriate safety measures to avoid possible irradiation damage.

Originality/Value: 

The analysis of the remnant effect of the UV-B before seeds sprouting has not been yet studied and its use could result in a beneficial effect on the germination and biosynthesis of phytochemicals in young plants.