TY - JOUR
T1 - Dissolution of calcium hydrogen phosphate in aqueous δ-gluconolactone; long-lasting supersaturation increasing calcium availability
AU - Cheng, Hong
AU - Skibsted, Leif Horsfelt
PY - 2018/9
Y1 - 2018/9
N2 - Calcium hydrogen phosphate dissolves readily in aqueous δ-gluconolactone/gluconate, forming solutions supersaturated in calcium gluconate by a factor up to seven at 25 °C. The critical gluconate concentration for dissolving calcium hydrogen phosphate to form homogeneous supersaturated solutions was linearly dependent on the concentration of dissolved calcium hydrogen phosphate rather than the δ-gluconolactone/gluconate ratio. Based on ion speciation, the solution was initially found spontaneously supersaturated with calcium gluconate, while the dissolution of calcium was limited by the solubility product of calcium hydrogen phosphate. After equilibration the concentration of dissolved calcium was controlled by the solubility product of calcium gluconate. The lag phase for initiation of precipitation of calcium gluconate from the supersaturated solutions were up to 9 d, and were slightly increased by presence of calcium saccharate. The transient increase in solubility of calcium hydrogen phosphate in the presence of gluconate may be exploited in functional foods, enhancing calcium availability.
AB - Calcium hydrogen phosphate dissolves readily in aqueous δ-gluconolactone/gluconate, forming solutions supersaturated in calcium gluconate by a factor up to seven at 25 °C. The critical gluconate concentration for dissolving calcium hydrogen phosphate to form homogeneous supersaturated solutions was linearly dependent on the concentration of dissolved calcium hydrogen phosphate rather than the δ-gluconolactone/gluconate ratio. Based on ion speciation, the solution was initially found spontaneously supersaturated with calcium gluconate, while the dissolution of calcium was limited by the solubility product of calcium hydrogen phosphate. After equilibration the concentration of dissolved calcium was controlled by the solubility product of calcium gluconate. The lag phase for initiation of precipitation of calcium gluconate from the supersaturated solutions were up to 9 d, and were slightly increased by presence of calcium saccharate. The transient increase in solubility of calcium hydrogen phosphate in the presence of gluconate may be exploited in functional foods, enhancing calcium availability.
U2 - 10.1016/j.idairyj.2018.03.014
DO - 10.1016/j.idairyj.2018.03.014
M3 - Journal article
SN - 0958-6946
VL - 84
SP - 62
EP - 71
JO - International Dairy Journal
JF - International Dairy Journal
ER -