TY - JOUR
T1 - Increasing calcium solubility from whey mineral residues by combining gluconate and δ-gluconolactone
AU - de Zawadzki, Andressa
AU - Skibsted, Leif H.
PY - 2019
Y1 - 2019
N2 - Insoluble milk mineral residues from whey processing, dominated by hydroxyapatite and calcium hydrogen phosphate, dissolved isothermally in aqueous gluconate/δ-gluconolactone, spontaneously forming solutions supersaturated in both calcium hydrogen phosphate and calcium gluconate. Calcium concentration of maximally supersaturated solutions was proportional to gluconate concentration, indicating gluconate assisted dissolution, while gluconolactone increased calcium available for dissolution and supersaturation. Precipitation of calcium gluconate, rather than of calcium hydrogen phosphate, was critical for supersaturation robustness. For calcium gluconate ionic product:solubility product of calcium gluconate ratios <12, the supersaturated solutions had a lag phase for precipitation of several weeks, which increased to several months by addition of solid calcium saccharate prior to dissolution of the mineral residues. Such supersaturated solutions with up to 7 g calcium L−1, corresponding to a factor of supersaturation of >100 times compared with equilibrium calcium hydrogen phosphate solubility, may be exploited for increasing calcium availability of whey mineral based functional foods.
AB - Insoluble milk mineral residues from whey processing, dominated by hydroxyapatite and calcium hydrogen phosphate, dissolved isothermally in aqueous gluconate/δ-gluconolactone, spontaneously forming solutions supersaturated in both calcium hydrogen phosphate and calcium gluconate. Calcium concentration of maximally supersaturated solutions was proportional to gluconate concentration, indicating gluconate assisted dissolution, while gluconolactone increased calcium available for dissolution and supersaturation. Precipitation of calcium gluconate, rather than of calcium hydrogen phosphate, was critical for supersaturation robustness. For calcium gluconate ionic product:solubility product of calcium gluconate ratios <12, the supersaturated solutions had a lag phase for precipitation of several weeks, which increased to several months by addition of solid calcium saccharate prior to dissolution of the mineral residues. Such supersaturated solutions with up to 7 g calcium L−1, corresponding to a factor of supersaturation of >100 times compared with equilibrium calcium hydrogen phosphate solubility, may be exploited for increasing calcium availability of whey mineral based functional foods.
U2 - 10.1016/j.idairyj.2019.104538
DO - 10.1016/j.idairyj.2019.104538
M3 - Journal article
AN - SCOPUS:85071287015
SN - 0958-6946
VL - 99
JO - International Dairy Journal
JF - International Dairy Journal
M1 - 104538
ER -