AGFD 7 |
| The following study compares the 24 h urinary excretion of isoflavone algycones after the consumption of fermented soybean paste or unfermented soy flour in a population of healthy Koreans (4 male and 5 female). An equivalent amount (20 mg) of total isoflavone (aglycone + glycosides) was consumed as either 52 g of soybean paste or 12.2 g soy flour in a randomized, crossover trial consisting of two single-time point feedings and having 3 day run-in and washout periods between feeding. Liquid chromatography-mass spectrometry (LC-ESI/MS/MS) analysis of starting materials indicates that daidzein (1.4%) and genistein (1.4%) comprised a smaller percent of the total isoflavones in soy flour as compared with soybean paste (55.3% daidzein and 45.7% genistein). Consequently, volunteers in this study consumed about 37 times more of the aglycones in the soybean paste as compared to soy flour. Free and glycosidic forms of isoflavones differed significantly between the two soy products. Levels of beta-glycosides as well as total glycosides (beta-glycosides, malonyl and acetyl forms) were 2-fold higher in soy flour as compared to soybean paste. Malonyl forms predominated in soy flour. The consumption of soybean paste resulted in significantly higher urinary excretion of both daidzein and genistein as compared with soy flour (P less than 0.05 and P less than 0.01, respectively).
|
|
Characterization and Bioavailability of Flavonoid Glycosides
8:00 AM-12:10 PM, Sunday, August 19, 2007 BCEC -- 255, Oral
Division of Agricultural & Food Chemistry |