Improved in vitro bioavailability of a newly developed functionalized calcium carbonate salt as a food ingredient and its comparison with available commercial calcium salts

Abstract The bioaccessibility and bioavailability of a functionalized Calcium (Ca) salt as food ingredient, based on modified Ca carbonate and hydroxyapatite (FCC), was determined and compared with frequently used Ca sources (Ca citrate tetrahydrate (CCT), tri-Ca phosphate (triCP) and Ca carbonate (CC). Results showed a similar Ca bioaccessibility for CCT (76.44 ± 9.73 %), CC (73.7 ± 8.18 %) and FCC (74.4 ± 1.87 %) and a lower value for tri-CP (46.07 ± 8.68 %). FCC showed the highest bioavailability, 5.68 ± 0.26 %, compared to CC, CCT and tri-CP (3.93 ± 0.99 %, 3.41 ± 0.33 %, 1.85 ± 0.34 %, respectively). The innovative chemical composition and structure of FCC based on amorphous hydroxyapatite combined with Ca carbonate, a greater porosity, lower agglomerates and particle size, improve the Ca solubility in the intestinal media, explaining the similar bioaccessibility but higher bioavailability of FCC compared to CCT, tri-CP and CC.