The addition of calcium is widely accepted as a tool in cheese-making but the effect on the microstructure
of cheese during and following manufacture is not known. In this study, cheeses made with
milk containing 200e600 mg L1 of additional CaCl2 had significantly lower fat loss into the whey
collected after cooking; however, the final fat composition or yield of cheese did not change. The
microstructure of the gel with 300 or 600 mg L1 CaCl2 addition was less porous and the cooked curd
consisted of a denser protein network that may retain more fat during the early stages of manufacture. In
contrast, the cheddared curd and cheese contained more micro-pores than cheeses with lower or no
calcium addition. Such micro-pores could possibly be the channels by which fat escaped during pressing.
This study shows that calcium addition altered the microstructure and pattern of fat loss during Cheddar
manufacture.