Effect of calcium chloride addition and draining pH on the microstructure and texture of full fat Cheddar cheese during ripening

• Calcium chloride added to milk did not significantly affect Cheddar ripening.
• Draining pH can counter effects of calcium addition on microstructure.
• A lower draining pH results in a harder cheese.

Calcium chloride is commonly added to cheese–milk to improve coagulum formation and to increase cheese yield but high concentrations of calcium ions can have adverse effects. In this study, confocal laser scanning microscopy and cryo-scanning electron microscopy were coupled with textural and chemical analyses to observe microstructural and biochemical changes that occur in cheese during ripening when calcium chloride is added or the draining pH altered. For the cheese prepared with no additional calcium at a draining pH of 6.0, the cheese porosity increased with ripening time and the number of protein vertices in the microscopy images declined, indicative of protein solubilisation. As the amount of CaCl2 added was increased, however, these changes became less significant. Our findings show that calcium chloride addition can be used, together with a lower draining pH, to alter the manufacturing process without significantly impacting on the quality of the mature cheese.