Influence of Copper on the Characteristics of Swiss-Type Cheeses

Sufficient cupric sulfate solution was added to cheese milk to give .25 to 1 ppm of copper. The resulting cheese had copper concentrations 8 to 13 times higher than that of the milk. Proteolysis increased in conventional Swiss cheese with increasing copper concentrations, but in Iowa-style Swiss, no relationship was consistent. The ratio of acetic to propionic acids was different in Iowa-style and conventional Swiss, but the amounts of these acids were not related to copper concentration. When the copper in Iowastyle Swiss cheese was increased, flavor acceptance declined, but with conventional Swiss cheese, the reverse was true. Copper increased the modulus of elasticity and coefficent of viscous traction in conventional cheese. The rate of production of carbon dioxide was decreased in Iowa-style cheese by about 11 ppm of copper. The reflectance of conventional Swiss cheese decreased more or less uniformly across the visible spectrum as it ripened, but this was not affected by copper.