SDS‐PAGE of Proteins in Goat Milk Cheeses Ripened under Different Conditions

Proteolytic characteristics of five varieties of commercial goat milk cheeses and a cow milk Cheddar aged under different conditions were evaluated by SDS‐PAGE and an advanced densitometry system. All fresh goat cheeses had distinctively lower intensities of α S1 ‐casein (CN) bands than those of cow milk Cheddar, whereas intensities of β‐CN were much greater in the goat cheeses. The PAGE patterns clearly displayed α S2 ‐CN in all goat cheese, but it was negligible in cow milk Cheddar. The greater protein degradation in hard goat cheeses than cow milk Cheddar at 4°C and 22°C strongly correlated with water‐soluble nitrogen compound concentrations and densitometric values of corresponding cheeses.