MONITORING PROTEOLYSIS DURING CHEDDAR CHEESE RIPENING USING 2-DIMENSIONAL GEL-ELECTROPHORESIS

A 2-D gel electrophoretic method, consisting of isoelectric focusing a nd alkaline urea-PAGE was used to monitor proteolysis during ripening (180d, 5 degrees C and 8 degrees C) of full- and reduced-fat Cheddar c heese. The method enabled quantifying changes in levels of peptides in cheese with good spot-resolution. Results can complement those from o ther analyses, especially those for determining low MW peptides. Notab le effects were found for cheese composition and ripening temperature on gel pattern and on relative levels of selected proteolysis products . In both cheese varieties, most peptides reached a maximum during the first 3 ripening months and gradually disappeared as ripening advance d.