Elemental composition, physicochemical properties, and calcium bioavailability of calcined gill powders from Asian seabass and catfish

Calcined gill powders (CGPs) from Asian seabass and catfish were prepared by calcination at 900 °C for 6 h. Seabass (SB-CGP) and catfish (CF-CGP) were characterized for their chemical composition, morphology, functional groups, and crystallinity. Cytotoxicity was assessed using BJ cells, and calcium bioavailability was compared with CaCO₃ using a Caco-2 cell model. Both CGPs had high ash content (99.21-99.58 %). SB-CGP showed a larger particle size and higher crystallinity than CF-CGP. The morphological structures of CGPs from two fish species were different. Ca, P, Mg, and Na were found in both CGPs, whereas S and K were detected only in CF-CGP. Notably, the Ca/P ratio in both CGPs exceeded the standard stoichiometric ratioof 1.67. Cytotoxicity assay of both CGPs showed high cell viability at all concentrations and time used. At 4 h, SB-CGP (44.31 %) and CF-CGP (43.86 %) demonstrated superior calcium bioavailability to CaCO₃ (36.24 %), suggesting their potential as alternative calcium supplementation.