Controlling Effect of Clove Extract on the Oxidation Sites in Porcine Myofibrillar Protein as Determined by Two Electrophoretic Methods

This study aimed to determine the oxidation by hydroxyl free radicals of the myosin head (S1) and tail (Rod) from porcine myofibrillar protein (MP) hydrolyzed by trypsin and to investigate the effect of clove extract on protein oxidation sites. To this end, unoxidized MP, oxidized MP and oxidized MP bound to clove extract were analyzed by one-dimensional electrophoresis, two-dimensional electrophoresis and mass spectrometry (MS). The results of one-dimensional electrophoresis showed that clove extract had a better protective effect on the S1 site. The small fragments generated by the decomposition of Rod and S1 were cross-linked to actin mainly through disulfide bonds. The results of two-dimensional electrophoresis and MS confirmed that subunits or fragments of major MP components such as myosin or actin were produced after MP oxidation, and the addition of clove extract effectively controlled the generation of these fragments, confirming the inhibitory effect of clove extract on protein oxidation at the molecular level. The MS identification of the peptides showed that the main amino acid sites modified by MP oxidation induced by hydroxyl radicals were methionine and cysteine. This study shows that the addition of clove extract in meat processing and storage can improve the functional properties of meat products.