Abstract: The effects of different light quality on growth，total phenolic contents，antioxidant and
phenylalanine ammonia-lyase（PAL）activity of radish sprouts have been investigated. The results showed
that the growth，total phenolic contents，antioxidant and PAL activity of radish sprouts that treated with
different light spectrum qualities varied with light quality and treatment time. The hypocotyl length and
growth of radish sprouts rapidly increased from 3 to 7 d，and then they increased slowly. Accumulated
phenolic in sprouts also showed the general trend distribution of early stage of culture > late stage of
culture. Compared to dark treatment，radish sprouts grown in UV-B treatment were found to have much
higher concentrations of phenolic. Accordingly，the antioxidant and PAL activity were highest in the UV-B
treatment. In addition，the blue light treatment also induced the PAL activity and increased the phenolic
content in‘Yanghua’radish sprouts. These results suggest that light treatments of radish sprouts，especially
UV-B and blue light，are effective in promoting dietary phenolic antioxidants and radish sprouts have the potential to be an effective source of bioactive compounds for the consumers.

Key words: radish, sprouts, light quality, total phenolic contents, PAL activity, antioxidant activity