Distribution of Salt and Moisture in Mozzarella Cheese with Soft Surface Defect

Brine-salted Mozzarella cheese sometimes develops a soft, wet surface during storage, and the objective of this study was to compare distributions of salt and moisture in two surface types of cheese blocks. Seven 9.1-kg blocks of Mozzarella with soft, wet surfaces and 5 9.1-kg blocks with firm, dry surfaces were obtained from five different cheese companies. Moisture and salt distributions were determined using a sampling plan that provided three concentric samples at different depths within each of three cross-sectional slices from the end of the block and three slices from the middle. Salt distributions in cheeses with soft, wet surfaces were similar to those in cheese with firm, dry surfaces; salt content increased from center to surface and was higher at the ends of the block. In contrast, moisture distribution differed markedly. The moisture content decreased from center to surface in blocks with firm, dry surfaces, but the pattern was the reverse in blocks with soft, wet surfaces, which also had higher moisture contents at the ends of the block. The data are consistent with the hypothesis that the temperature differential, which develops during exposure of the warm cheese to cold brine and then dissipates slowly during postbrine cooling, is important in the development of soft surface defect.