Population changes of citratefermenting bacteria in cheddar cheese

Population changes of citrate fermenting bacteria in commercial Cheddar cheese and flavor developments of the cheese were studied. Ten freshly made Cheddar cheese were purchased from five different manufacturers and the cheese were examined for citrate fermenting bacteria at regular monthly intervals during a twelve month curing period. The Citrate fermentation bacterial populations were enumerated on tomato juice agar containing 0.5 per cent calcium lactate and 0.6 per cent colloidal calcium citrate. After three months of curing, the examination included organoleptic test for the flavor and texture of the cheese.

Eight of ten cheese contained citrate fermenting bacteria throughout curing in variable numbers and two cheese contained the bacteria until eleven months of curing.The populations of citrate fermenting bacteria of all cheese decreased during curing. Six of ten cheese developed a bitter flavor during curing. Two of the remaining cheese developed a fermented flavor and the other two a flat flavor.All cheese showed slight to distinct openness in texture when examined after three months of curing and there was no change in the degree of openness throughout the curing.