Concentrations of total isoflavones in soybean varieties of different origi
ns and soybean products were determined by high performance liquid chromato
graphy. Wild soybeans showed the trend to have more isoflavone content than
cultivars or landraces, showing mean value of 1528, 1265 and 1249 mg kg(-1
), respectively. There were no meaningful differences in the ratio of genis
tein and daidzein among the modern variety groups. Korean varieties includi
ng South Korea and North Korea seemed to have total isoflavone content more
than Chinese varieties, although samples of Chinese varieties were limited
. In a dried basis of soyfoods, total isoflavone contents were in order of
soybean sprout, chungkukjang, soymilk, soybean curd, denjang, kochujang, re
spectively. Five soybean foods contributed 96% of total genistein and daidz
ein intake in Korea: soybean sprout, soybean curd, denjang, chungkukjang an
d soybean seed itself. According to a Korean National Survey Report and our
data, the average Korean daily intake of isoflavone from soybean foods can
be estimated as 21 mg day(-1). (C) 2000 Society of Chemical Industry.