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. β-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.