title: Effects of calcium chelators on calcium distribution and protein solubility in rennet casein dispersions.
abstract: This study investigated the effects of calcium chelating salts on calcium-ion activity (ACa(++)), calcium distribution, and protein solubility in model CaCl2 solutions (50 mmol L(-1)) or rennet casein dispersions (15 g/100 g). Disodium phosphate and trisodium citrate at concentrations of 10 and 30 mmol L(-1) and at ratios of 1:0, 2:1, 1:1, 1:2 and 0:1 were added to both systems. The CaCl2 system, despite its simplicity, was a good indicator of chelating salt-calcium interactions in rennet casein dispersions. Adding trisodium citrate either alone or as part of a mixed chelating salt system resulted in high levels of dispersed "chelated" calcium; conversely, disodium phosphate addition resulted in lower levels, while the ACa(++) decreased with increasing concentration of both chelating salts. Neither chelating salt produced high levels of soluble protein. Thus calcium chelating salts may play a more subtle role in modulating hydration during manufacture of casein-based matrices than simply solubilising calcium or protein.
authors.affiliation: UCD Institute of Food & Health, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Irene
authors.initials: I
authors.lastname: McIntyre
authors.affiliation: UCD Institute of Food & Health, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: Michael
authors.initials: M
authors.lastname: O' Sullivan
authors.affiliation: UCD Institute of Food & Health, University College Dublin, Belfield, Dublin 4, Ireland. Electronic address: dolores.oriordan@ucd.ie.
authors.forename: Dolores
authors.initials: D
authors.lastname: O' Riordan
mesh_terms: D000818:Animals; D065096:Calcium Chelating Agents / Q000737:chemistry / Q000494:pharmacology*; D002122:Calcium Chloride / Q000737:chemistry / Q000494:pharmacology; D002136:Calcium, Dietary / Q000032:analysis*; D002364:Caseins / Q000737:chemistry*; D012085:Chymosin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D008892:Milk / Q000737:chemistry*; D008956:Models, Chemical; D010710:Phosphates / Q000032:analysis; D012995:Solubility; D012996:Solutions
chemical_list: D065096:Calcium Chelating Agents; D002136:Calcium, Dietary; D002364:Caseins; D008823:Micelles; D010710:Phosphates; D012996:Solutions; C025350:rennet; D012085:Chymosin; D002122:Calcium Chloride
keywords: Calcium chelating salts; Chelation; Protein solubility; Rennet casein