Calcium, Fe, Cu, Zn, and Mg Fractionation in In Natura and Aged Beef Samples by Bioanalytical Methods

Proteins play different and essential roles in the human organism. Containing essential amino acids, proteins, and minerals, beef is considered the main source of protein in human nutrition. It is generally accepted that the protein profile is directly correlated to tenderness and beef pigmentation and is also related to its organoleptic properties. In the present work, it is demonstrated the changes in protein profile, differences of metal concentrations, and how metals bonded to proteins can vary during the ripening phase, evaluated over a 14-day beef aging period. The proposed extraction procedure indicated 85% efficiency, preserving the metal-protein structure. Seventeen protein bands were detected using SDS-PAGE, and a 43-kDa band was found to be the most intense. The arrangement of SDS-PAGE and SEC-ICP-MS results indicated the possible links between minerals and organic functional molecules, such as Ca to troponin, Cu and Zn to albumin, and Fe to myoglobin and hemoglobin.