Determination of aglucone isoflavones in non-transgenic and transgenic soybeans (GLYCINE MAX L.) by HPLC-DAD

Soybeans, an important global crop, is an excellent source of oil and proteins and also contain many other compounds, including isoflavones, which have been the subject of several studies demonstrating their potential in the treatment of menopause and osteoporosis. This paper describes a method for quantification of the aglucone isoflavones found in soybeans using high performance liquid chromatography with diode array detection after extraction of the total isoflavones followed by acid hydrolysis. The quantities of the total aglucone isoflavones (daidzein, glycitein and genistein) in non-transgenic (BRS133) and transgenic (BRS245RR) soybeans, planted in the same region (north of Parana State, Brazil) and in the same period of the year, in 100 g of soybeans, were 284 +/- 10 mg and 228 +/- 13 mg for the non-transgenic and transgenic soybean varieties, respectively.