The total concentration and bioaccessible fraction of nutrients in purées, instant cereals and infant formulas by ICP OES: A study of Dietary Recommended Intakes and the importance of using a standardized in vitro digestion method

Innumerable food products and supplements for infants and children are commercially available, so the total concentration of Ca, Cu, Fe, K, Mg, Mn, and Zn and the bioaccessibility of Cu, Fe, Mg, Mn, and Zn in fourteen of these products were investigated. Analysis was performed by inductively coupled plasma optical emission spectroscopy after microwave oxidative digestion for total concentration, and a standardized in vitro digestion method was used for the bioaccessible fraction. The total concentration and the bioaccessibility varied greatly according to the sample type (fruit or salty purées, instant cereals and infant formulas). According to the Dietary Reference Intake (DRI), the infant formulas and fruit purées showed the highest and lowest contributions, respectively, when the sample amount ingested in a single meal was considered. As expected, the bioaccessibility was lowest for Fe, intermediate for Cu and Mn and highest for Mg. The bioaccessibility values were 28-38% (Cu), 0-23% (Fe), 41-63% (Mg), 24-60% (Mn), and 22-91% (Zn), with the exception of infant formulas, which showed higher bioaccessibility values (>60%) for all elements. Therefore, a diet based on these industrially prepared food products and supplements may provide an adequate intake of minerals.