Effect of Oxidation on the Structure,Emulsification and Gelability of Rabbit Meat Myofibrillar Protein

To investigated the effects of oxidative modifications on rabbit meat myofibrillar protein(MP)structures as well as their emulsifying properties and gel texture properties caused by oxidation. In this paper,oxidative treatment of rabbit meat myofibrillar protein was carried out using 0~10.0 mmol/L AAPH-derived(2,2'-azobis(2-amidinopropane)dihydrochloride)peroxyl radicals. The results showed that with the increasing of AAPH concentration,the free thiols content,intrinsic fluorescence intensity and protein emulsification stability of rabbit meat MP decreased,while the carbonyl content,bityrosine content,protein particle size and emulsifying activity increased(P<0.05),the surface hydrophobicity tends to increase first and then decrease and then increase again. Results from polyacrylamide gel electrophoresis(SDS-PAGE)indicated that low concentration of AAPH(0~1.0 mmol/L)and relatively high concentration(10.0 mmol/L)induced aggregation and cleavage of the protein,respectively. These structural changes resulted in changes on the gel texture of myofibrillar protein.Moderate protein oxidation(AAPH 0~1.0 mmol/L)improved the texture properties of the gel of rabbit meat,while further oxidation(AAPH 1.0~10.0 mmol/L)significantly reduced the properties of the gel(P<0.05). Therefore,the oxidative modification of peroxyl radicals can significantly affect the structure,emulsification and gelability of rabbit meat MP(P<0.05).