Changes in myoglobin content in pork Longissimus thoracis muscle during freezing storage

In this study, pork Longissimus thoracis muscle was used, which was frozen in a chamber and thawed under controlled conditions. The color profile and the surface myoglobin were evaluated. A thermal analysis was performed by modulated differential scanning calorimetry (MDSC), and Fourier-transform infrared spectroscopy with attenuated total reflection (FTIR-ATR). It was found that there were important effects in myoglobin due to the freeze-thawing process in parameters such as pH, luminosity (L*), and chroma values, as well as in activation energies (Ea) and denaturation enthalpy (ΔH) between myoglobin forms. In raw meat, it was found that there was a greater proportion of deoxymyoglobin, and in frozen-thawed samples, metmyoglobin was the most abundant form, indicating that are significant effects which are correlated with the changes in tri-stimulus coordinates and with the thermal and chemical parameters in pork meat.