- loss of calcium phosphate determines extent of casein micelle disruption--hence it determines basic cheese structure; the important parameter is the ratio of Ca to casein or Ca to SNF which is easier to measure (See Table 1.1)
- in Swiss (high Ca, about 750 mM Ca/kg SNF) micelle globular structure is intact while extensive dissociation and disruption of submicelles is evident in Feta types (low Ca, about 400 mM Ca/kg SNF))
- retention of calcium phosphate in the cheese also increases the buffer capacity of the cheese
- pH at draining determines the solubility of calcium and phosphate when the curd is separated from the whey
- more Ca is retained at high draining pH as in Swiss cheese (pH 6.4 - 6.5) versus Cheddar 6.1 - 6.3 (See Table 1.1).
- little Ca retained in Feta cheese which needs some explanation:
Feta is dipped into the forms early while the pH is still quite high. However, the moisture is also high because no cooking has taken place. Therefore, the moisture is removed by syneresis as the pH decreases while the cheese is in the forms. The net result is that a great deal of moisture (whey) is removed at low pH and most of the calcium phosphate is removed with it. This is also true for other soft ripened cheese like blue and camembert.