Effect of Oxidation on Rheological Properties and Structure of Myofibrillar Protein

The study was designed to reveal the effect of protein oxidation on rheological properties during heating,hydrophobic interaction and secondary structure of chicken myofibrillar protein(MP)gel using lipoxygenase-linoleic acid system. The internal relationship between MP rheological properties during heating,protein secondary structure in gel state and hydrophobic interaction was revealed. The results showed that,MP samples with a linoleic acid concentration of 2 mmol/L had the largest G' value(>68 ℃)compared with other linoleic acid concentrations. With the addition of linoleic acid,the α-helix content decreased from 48.31% in the unoxidized state to the lowest value of 29.57% in the case of linoleic acid 10 mmol/L,while the β-sheet content gradually increased from 14.75% to 22.14%. The β-turn content also increased from 16.28% to 21.88% with the increase of oxidation degree,and the content of random coil generally showed an increasing trend. As the degree of oxidation increased,the hydrophobic interaction of the MP gel firstly increased and then decreased,reaching a maximum at 2 mmol/L,while the G' value(>68 ℃)reached a maximum at 2 mmol/L,which showed that the change of hydrophobic interaction was closely related to the change of protein secondary structure in MP gel.