Study Effect On Chemical Interactions Of Myofibrillar Protein Gels

The nature on heat induced gels formation of myofibrillar proteins is an important functional properties of meat processing, its plays a decisive role on gel characteristics, rheological properties and product rate of meat. How to improve the gel strength and meat gel quality of re-composed meat products, functional meat products and minced meat products is the important issues of meat processing. The RFN meat and PSE meat of longissimus muscle as the testing raw materials, study the gel strength and chemical interactions changes of myofibrillar proteins gels were under different conditions, to further reveal the gels formation principle of myofibrillar protein and the control the meat characteristics to provide theoretical guidance. The major findings as follows:1. The changes on gels strength of myofibrillar proteinStudy found, between pH5.7-6.6, with the pH value lower the gel strength of the normal meat and PSE meat MP increased significantly, with the NaCl concentration increases in the 0～0.6mol/L range, the gel strength of normal MP meat and PSE meat significantly increased, and PSE meat in the NaCl concentration to 0.5mol/L or more, the gel strength without adding NaCl to be slightly higher than normal meat. In the test range, the gel strength of normal meat and PSE meat MP significantly increased as the TPP concentration increases, when TPP concentration reached to 0.2% gel strength of two groups to the maximum; in the test range, as the divalent metal ion concentration increases, the gel strength of normal MP meat and PSE meat is the same trend. The gels strength is not significant when the Ca²⁺concentration below 0.02mol/L, but more than this concentration, the gel strength increased significantly with the Ca²⁺concentration increases. Fe²⁺concentration and Mg²⁺concentration have not significant impact on gel strength of MP. Heating onset temperature different has a intensity impact on the gel strength. The gels formed at low onset temperature by heating have a higher gel strength than at high onset temperature heated.2. The changes on covalent bonds content of myofibrillar protein gelsAs the pH value increases from 5.7 to 6.6, the disulfide bonds content of RFN and PSE meat myofibrillar protein gel decreased, while gel strength decreased significantly, therefore, within the test range pH increased have an significantly impact with disulfide bonds and proteins gel strength, and the disulfide bond has an important contribution to the MP gel strength. In the test range, as the NaCl concentration increased, the changes on disulfide bonds content of normal meat and PSE meat MP gels is not significant, while the gel strength of two samples were significantly higher, thus, test range the force impact the proteins gel strength is not disulfide bonds when the NaCl concentration increased, but other forces. Within the test range, disulfide bonds content of normal meat and PSE meat MP gel have no significant changes with the TPP concentration increases, while the gel strength of two samples significantly enhanced, therefore, within the test TPP concentration increases, the force impact the proteins gel strength is not disulfide bonds, but other forces. In the test range, Mg²⁺and Fe²⁺concentration increased have no obvious impact on disulfide bonds content of normal meat and PSE meat MP gels, while within the scope of test gel strength have no significant change, and Ca²⁺concentration increases, the disulfide bonds content of normal meat and PSE meat MP gel increases, the same time, within the scope of this test the gel strength significantly increased, therefore, Mg²⁺and Fe²⁺concentration increase had no effect on the disulfide bonds and gel strength of the proteins, while the Ca²⁺concentration increases, the disulfide bonds have important contribution to proteins gel strength. In the range of experiment, with the heating temperature increases, the disulfide bonds content of normal meat and PSE meat MP gel is decreased, meanwhile, in the test scope gel strength significantly reduced, so the test conditions, the heating onset temperature increases, the disulfide bonds is the major forces affect proteins gel strength.3. The changes on other forces of myofibrillar protein gelsWhen the pH value rises from 5.7 to 6.6, electrostatic interaction, hydrogen bonds, hydrophobic interaction of RFN and PSE meat MP gels change significantly, while the gel strength was significantly reduced, therefore, when pH increases, the hydrophobic interaction have a certain contribution to the proteins gel strength, while the effects of electrostatic interaction and hydrogen bonds on proteins gel strength is out of law. in the range of experiment, the electrostatic interaction, NaCl concentration increases have a significantly impact on hydrophobic interaction of normal meat and PSE meat MP gel and the hydrogen bonds of PSE meat MP gels, while the effect on hydrogen bonds of RFN meat gels on is small, while the gel strength increased significantly, Therefore, NaCl concentration increases, the effect of hydrogen bonds on the proteins gel strength is out law, electrostatic interactions have a certain contribution to the proteins gel strength, hydrophobic interaction is not the force affected gel strength, in the experiment range, TPP concentration increases have a significant effect on the electrostatic interaction and hydrogen bonds of normal meat and PSE meat MP gels, while the impact on the hydrophobic interaction was not significant, while the gel strength increased significantly, therefore, when TPP concentration increases, the electrostatic interaction is the force of PSE myofibrillar proteins affected gel strength, hydrogen bond is the force affect gel strength of normal meat gels, hydrophobic interaction is not the force affect the gel strength, within the test set, Mg²⁺concentration increases have a significant effect on the electrostatic interaction, hydrogen bonds, hydrophobic interaction of normal meat and PSE meat MP gels, while the gel strength change unsignificantly, so Mg²⁺concentration increases, the electrostatic interaction, hydrogen bonds, hydrophobic interactions is not the force affect the proteins gel strength, in the test range, Ca²⁺concentration increases had significant effect to the electrostatic interaction and hydrophobic interactions of normal meat and PSE meat MP gels, but has little effect on the hydrogen bonds, while the gel strength increased significantly, therefore, when Ca2+ concentration increases, the electrostatic interaction and hydrophobic interaction is the major force that affect the gel strength, while the hydrogen bonds have no contribute to the gel strength. In the test range, Fe²⁺concentration increases have no significantly affect to the electrostatic interaction, hydrogen bonding, hydrophobic interactions of normal meat and PSE meat MP gels, while the gel strength changs was not significant, therefore, Fe²⁺concentration increases have no effect on the electrostatic interaction, hydrogen bonding, hydrophobic interactions and proteins gel strength, electrostatic interaction, hydrogen bonding, hydrophobic interaction is not the forces affect gel strength. In the test range, the heating onset temperature increases have a greatly influence on the electrostatic interaction and hydrophobic interaction of normal heating meat and PSE meat MP gels, and the impact on the hydrogen bond smaller, while the gel strength decreased significantly, therefore, when the heating onset temperature increases, the hydrophobic interaction is an important force affects the gel strength, of hydrogen bonds is not the force affects gel strength, electrostatic interaction effect on the gel strength is out the law.