Dissolution and storage stability of nanostructured calcium carbonates and phosphates for nutrition
Abstract
Rapid calcium (Ca) dissolution from nanostructured Ca phosphate and carbonate (CaCO3) powders may allow them to be absorbed in much higher fraction in humans. Nanosized Ca phosphate and CaCO3 made by flame-assisted spray pyrolysis were characterized by nitrogen adsorption, X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy. As-prepared nanopowders contained both CaCO3 and CaO, but storing them under ambient conditions over 130 days resulted in a complete transformation into CaCO3, with an increase in both crystal and particle sizes. The small particle size could be stabilized against such aging by cation (Mg, Zn, Sr) and anion (P) doping, with P and Mg being most effective. Calcium phosphate nanopowders made at Ca:P ≤ .5 were XRD amorphous and contained γ-Ca2P2O7 with increasing hydroxyapatite content at higher Ca:P. Aging of powders with Ca:P = 1.0 and 1.5 for over 500 days gradually increased particle size (but less than for CaCO3) without a change in phase composition or crystallinity. In 0.01 M H3PO4 calcium phosphate nanopowders dissolved ≈4 times more Ca than micronsized compounds and about twice more Ca than CaCO3 nanopowders, confirming that nanosizing and/or amorphous structuring sharply increases Ca powder dissolution. Because higher Ca solubility in vitro generally leads to greater absorption in vivo, these novel FASP-made Ca nanostructured compounds may prove useful for nutrition applications, including supplementation and/or food fortification. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000121568Publication status
publishedExternal links
Journal / series
Journal of Nanoparticle ResearchVolume
Pages / Article No.
Publisher
SpringerSubject
Flame-assisted spray pyrolysis (FASP); Calcium carbonate; Calcium phosphate; Doping; Aging; Dissolution; FoodOrganisational unit
03957 - Zimmermann, Michael Bruce (emeritus) / Zimmermann, Michael Bruce (emeritus)
02891 - ScopeM / ScopeM
Notes
It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.More
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