Calcium, iron, zinc and copper transport and uptake by Caco-2 cells in school meals: Influence of protein and mineral interactions

A combined in vitro digestion/Caco-2 cell culture system is used to estimate calcium, iron, zinc and copper transported and cell uptake (retention plus transport) corresponding to 8 dishes usually distributed to a Spanish school lunchroom, with an evaluation of the influence of proteins and mineral interactions. Mineral uptake percentages were as follows: Ca (3.3–56.3), Fe (7.8–67.4), Zn (5.6–54.9), Cu (14.6–96.6). The protein content of the menus analyzed (22.9–162.9 mg/g) exerts a positive influence upon iron uptake (r = 0.938), and a negative influence upon calcium uptake (r = −0.755) – with no influence upon the uptakes of either Zn or Cu. Mineral interactions are observed at dietary concentrations in the school menus studied. A negative and positive interaction is seen between soluble iron after in vitro digestion and Zn transported (r = −0.733) and Cu retention (r = 0.800), respectively. Solubilized Zn exerts a negative influence upon iron retained (r = −0.831).