Effect of Packaging and Storage Conditions on Calcium Lactate Crystallization on the Surface of Cheddar Cheese

Eight vats of milled curd Cheddar cheese were manufactured in a commercial cheese plant. Four consecutive vats (controls) were made according to the routine manufacturing schedule used at the cheese plant. Curd pH at drain was 6.30 and pH of the curd at mill was 5.45. Four experimental vats were made similarly to the controls except that the cook (stir-out), and cheddaring times were changed to facilitate draining and milling at a curd pH of 6.10 and 5.30, respectively. The development of calcium lactate crystals was evaluated on 255-g pieces of cheese packaged with a gas flush and heat sealed or vacuumed and heat sealed and stored at 4.4 or 7.2"C. The experimental vats had lower total lactic acid concentrations than did the control vats but few differences were observed in the extent of calcium lactate crystal formation between control and experimental vats. Although seemingly contradictory, cheeses with no crystals also had the lowest total and D(-)-lactic acid. Crystals developed faster and to a greater extent in gas-flushed packaged cheeses stored at 4.4"C than in similarly packaged cheeses stored at 7.2"C. Very little crystal development was observed in vacuum-packaged cheeses until 5 mo after packaging, regardless of storage temperature. The package condition, Le., integrity of the packaging material to the cheese surface, played the major role in preventing the development of calcium lactate crystals.