Physicochemical characteristics of calcium supplemented skim milk:: comparison of three soluble calcium salts

Additions of calcium gluconate, calcium lactate and calcium chloride to skim milk from 0 to about 16 mmol.kg(-1) were carried out in parallel. Supplementation with these salts led to similar calcium association with casein micelles of about 80%. Whatever the added calcium salt, physicochemical consequences of the added calcium concentration were the same: i) increases in ionic strength and decreases in ultrafiltrate anion concentration (inorganic phosphate and citrate); ii) incorporation of casein molecules in casein micelles; iii) decrease in tightly bound water of ultracentrifuged pellet; iv) physicochemical changes of casein micelles (modification in the ratio of hydrophobic interactions versus ionic interactions) and v) decrease in heat stability.