The consumption of soyfoods is of great interest because of their proposed
anticancer and antiatherogenic activity. It has been suggested that the soy
isoflavones genistein and daidzein are responsible for these activities. T
he objective of this study was to determine the variation of the isoflavone
content of commercially available packaged tofu by brands and batches. The
content of total genistein and daidzein/glycitein aglycones in tofu sample
s was determined by highperformance liquid chromatography after acid hydrol
ysis in 23 different brands and different batches of four of these brands.
Between different tofu brands the genistein and daidzein/glycitein content
varied from 0.07 to 0.34 mg/g and 0.10 to 0.24 mg/g wet weight, respectivel
y. The isoflavone content from batch to batch of the same brand varied betw
een 7 and 28% based on dry weight. Assuming a daily consumption of 30 g soy
products, the isoflavone intake could vary between 5.4 and 17.1 mg/day. (C
) 2001 Academic Press.