Haem-mediated protein oxidation affects water-holding capacity of beef during refrigerated storage.

Haem is considered to be a potential producer of meat oxidation and the effect of its mediated oxidation on the water holding capacity (WHC) of beef is not yet clear. This work investigated the interrelationships between haem, protein and lipid oxidation, and WHC in beef during refrigerated storage. The increase in juice loss during storage ( < 0.05) indicates a reduction in WHC. Haem was oxidised, resulting in its structural disruption and an increase in the proportion of random coil in the protein secondary structures ( < 0.05). Extractable haem iron content was decreased and non-haem iron content was increased ( < 0.05), indicating the degradation of haem and the release of iron during storage. The levels of lipid and protein oxidation products significantly increased throughout the storage time ( < 0.05). Furthermore, Spearman analysis verified significant correlations between these changes. In conclusion, these processes are mutually reinforcing and may exacerbate muscle juice loss.