Variation of isoflavone contents in Korean soybean cultivars released from 1913 to 2006.

This study was carried out to evaluate the variation of isoflavone contents in 106 soybean cultivars released from 1913 to 2006 in Korea. A total of seed isoflavone content including genistein, daidzein and glycitein contents ranged from 527.9 μg/g to 3436.5 μg/g with an average of 1489.0 μg/g. The daidzein content ranged from 153.0 μg/g to 1710.4 μg/g with an average of 650.5 μg/g and the glycitein content ranged from 32.2 μg/g to 308.2 μg/g with an average of 146.2 μg/g. The genistein content ranged from 203.4 μg/g to 1502.4 μg/g with an average of 692.3 μg/g. Soybean cultivars which showed higher total of isoflavone content than any other cultivars were ‘Baegcheon’ (2553.9 μg/g), ‘Bosuk’ (3436.5 μg/g) ‘Daehwang’ (2709.2 μg/g), ‘Daemang 2’ (2595.0 μg/g), ‘Jangki’ (2769.9 μg/g), ‘Pungwon’ (2872.8 μg/g), ‘Sojin’ (2521.8 μg/g), and ‘Sorog’ (2956.1 μg/g). ‘Bosuk’ showed the highest total of isoflavone content among Korean soybean cultivars. Significant differences in isoflavone contents appeared to be related with the released years, edible use types, seed sizes and breeding locations in Korean soybean cultivars. Cultivars released in 2000s showed the highest total of isoflavone content, followed by both 1980s and 1990s, and before 1980 showed the lowest content. Cultivars for bean sprouts showed the highest total of isoflavone content, for soy sauce and paste showed the second highest content, followed by cooking with rice, and vegetable and early maturity showed the lowest content according to edible use types. Small seed cultivars showed the highest total of isoflavone content, followed by medium seed, and large seed showed the lowest content. Among three breeding locations, Iksan showed the highest total of isoflavone content, followed by Milyang, and Suwon showed the lowest content.