Quantification of beef myofibrillar proteins by SDS-PAGE.

A semi-quantitative determination of beef myofibrillar proteins using sodium, dodecyl sulphate polyacrylamide gel electrophoresis is described. Bovine serum albumin was used as internal standard. Results indicate a linear relationship between densitometric readings after staining with Coomassie brilliant blue R(250) and protein content. Recoveries of four pure proteins, loaded within a range of 0·5-4 μg, were between 92 and 110%. Heating of beef myofibrillar protein samples during dissolution is shown to be unnecessary. The method allows the quantitative study of myofibrillar degradation during beef aging, without overlapping of troponin-T with tropomyosin bands.