Abstract: Abstract: 【Objective】The effects of extrusion temperature on the microstructure of extrudates, protein solubility in 5 solvents, total sulphhydryl and disulfide bonds contents of extrudates were investigaged, and the effects of succinylated modification before extrusion on the structures and rheology properties of extrudates were also discussed in this paper, and aimed to grope for the mechanisms of peanut protein high moisture extrusion texturization. 【Method】The microstructures of extrudates observed by scanning electron microscope, the rheology properties of extrudates analysed by texture profile analyzer, and the conventional chemical methods were used to determined the total sulphhydryl and disulfide bonds contents of extrudates and succinylation of peanut protein. 【Result】(1) The solubility of peanut protein was greatly decreased with extrusion temperature increasing, but the protein solubility obviously increased when buffer contained sodium dodecyl sulphate (SDS), alone or combination with 2-mercaptoethanol (2-ME); The changes of total sulphhydryl contents among extrudates were not significant, disulphide contents of extrudates slightly decreased at 140-150℃, and decreased significantly at 155℃. (2)The hardness, chewiness and texturized degrees of extrudates were significantly decreased with peanut protein succinylated modification before extrusion. The microstructure of extrudates identified the changes of the rheology properties.【Conclusion】(1) Hydrophobic interactions and hydrogen bonds played the main function, and disulphide bonds was the second during peanut protein texturization. (2) Disulfide bonds in peanut protein molecules were cleaved during extrusion, and the higher temperature could accelerate this reaction. (3) Succinylated modification could disturbed the interactions between protein molecules and hindered the fibrous structure formation during extrusion texturization.

Key words: peanut, protein, extrusion texturization, chemical bonds, succinylated modification