Isoflavones and soyasaponins in soy infant formulas in Brazil: Profile and estimated consumption

In the present study we determine the contents of isoflavones and soyasaponins in seven soy-based infant formulas available in the Brazilian market to estimate the intake of these bioactive compounds by infants. The mean contents of isoflavones and soyasaponins were 65.9 mg/kg and 55.0 mg/100 g, respectively. beta-Glycosylated isoflavones and soyasaponin B-I were the most abundant components in the analysed samples. The mean estimated intake of isoflavones by infants fed soy-based formulas was 0.8 mg/day/kg of body weight, which is twice that of Japanese adults. For soyasaponins, the mean estimated intake was 9.2 mg/day/kg of body weight, which is up to 6 times higher than the daily intake of saponins from beans by vegetarians. Considering the estimated intake of these bioactive compounds from soy-based formulas and the paucity of data regarding their bioavailability, the potential biological effects of isoflavones and soyasaponins in infants should not be overlooked and merits further investigation. (C) 2013 Elsevier Ltd. All rights reserved.