Protein aggregation in cooked pork products: new details on the supramolecular organization.

The molecular weight distribution of protein aggregates from raw meat and cooked pork products was assessed by size exclusion–high performance liquid chromatography (SE–HPLC). Electrophoretic analysis under reducing conditions showed that the high molecular weight SE–HPLC peak (peak 1) of the cooked products contained protein aggregates in addition to high molecular weight muscle proteins, while the second peak (peak 2) still contained aggregates and<50 kDa proteins. The protein aggregates composition was investigated by HPLC–tandem mass spectrometry. Different classes of proteins were identified and the cooked products showed a more complex composition and organization, according to the muscle structure and the technological procedures, respectively. The key role of actin in the building of the protein networks was also confirmed. The different multi-protein systems found in the cooked products suggest protein re-organization in heat-induced supramolecular structures, which might be responsible for the texture and the structural properties of the final products.