Chicken thigh, chicken liver, and iron-fortified wheat flour increase iron uptake in an in vitro digestion/Caco-2 cell model

The objective of this study was to test meat and fortified-food combinations to identify those that optimize iron uptake in an in vitro digestion/Caco-2 cell model, a proxy for iron bioavailability. Four experiments tested combinations of meats such as chicken (blood, spleen, liver, thigh), beef (cube steak), and fish (whole-fish meal) with iron-fortified foods (rice cereal, maize-soy flour, wheat flour). Chicken liver, thigh, spleen, blood, or fish meal increased the Caco-2 cell iron uptake from these combined with rice cereal (P < .05). Chicken liver, thigh, blood, and beef increased the Caco-2 cell iron uptake from these combined with wheat flour (P < .05). Chicken liver and thigh were tested further. Compared with the liver or thigh alone, adding fortified foods to these meats did not increase the Caco-2 cell iron uptake (P ≥ .05). Adding either meat to the 3 fortified foods increased the Caco-2 cell iron uptake of the fortified foods (P < .05). Chicken liver, chicken thigh, and wheat flour were selected for an infant porridge because the combinations with the highest Caco-2 cell iron uptake were chicken thigh + wheat flour, chicken liver + wheat flour, and chicken liver + maize-soy flour, and wheat flour was the least expensive fortified food sold in the target population. Per unit of iron, the chicken thigh + wheat flour and chicken liver + wheat flour combinations resulted in the highest bioavailable iron. In the proportion of 3:1 fortified food:meat examined, meat increases the bioavailability of iron-fortified foods, but iron-fortified foods do not enhance total iron bioavailability when added to meat.