Effects of LEDs on the Germination, Growth and Physiological Activities of Amaranth Sprouts

Abstract

This study was conducted to clarify the effect of light-emitting diode (LED) for the light quality on the germination and physiological activity of amaranth (Amaranthus spp.) sprouts. We have germinated and grown the amaranth sprouts with blue, green, red, white, yellow, red+blue color lights for 14 hours and the dark condition for 10 hour, at the temperature of 25℃ (daytime) / 18℃ (nighttime). We have also made amaranth sprout extracts by methanol and examined into their physiological activities. All seed germination of amaranth sprouts were completed within 3 days after seeding irrespective of light sources. The fresh weight of total sprout has been increased in amaranth sprouts, which showed no significant meaning among the different treatments. However, the physiological activities indicated a significance meaning among the different light quality treatments. The total phenol compound contents were extremely increased in amaranth sprouts grown under the blue color light and the mixed light of blue and red color. And the total flavonoid contents were significantly increased under the red+blue light by 21.2 ㎎·L-1 which increased twice compared with the control. DPPH radical scavenging activity at 2,000 ㎎·L-1 were increased over 34% which were sprouted and grown under the blue or mixed light of red and blue color compared with the control. Nitrite radical scavenging activities of sprouts were most decreased compared with the control when grown under all lights except yellow light. Mushroom tyrosinase inhibition activity of amaranth sprouts was much lower than the control under the blue and mixed light of blue and red color.