Comparison of Anthocyanin Contents in Amaranth Sprouts According to the Different Cultivation and Low-temperature Treatment

This study was conducted to clarify the effects of culture condition and light or dark treatment to the anthocyanins of four edible amaranth cultivar’s sprouts. We germinated and grew the amaranth sprouts in four conditions: 1) hydroponic culture in growth chamber (23 °C); 2) soil culture in growth chamber (23 °C); 3) soil culture in greenhouse; and 4) grown in field. Anthocyanin content was the highest under greenhouse and field conditions, the lowest value was in soil culture in growth chamber. The effect of low temperature treatment on the antocyanin content was investigated. Amaranth sprouts grown in the greenhouse were treated low temperature. The low temperatures were 8, 12, 16, and 20 °C. After 1 week, we investigated the fresh weight of sprouts and sampled for analysis of anthocyanin content.  Anthocyanin content was the highest at 12 °C, followed by 16, 8, and 20 °C in that order. We investigated the changes of anthocyanin content when treated light and dark at 12 °C. The fresh weight, length, and width of sprouts were the highest in the control, but the anthocyanin content in sprouts was higher in the dark treatment than in the light treatment. Results show that amaranth sprouts grown to a low-temperature and dark treatment increased the anthocyanin content.