Study On The Synthesis And Property Of Starch-Soybean Protein-Guar Gum Graft Compolymers

The reduction carbonyl of starch and edible gum polysaccharide can covalently bond to the free amino of protein under certain condition, then change the function characteristics of soybean protein isolate. In this paper, denatured starch, soybean protein isolate and guar gum are studied, dry-process, wet process and microwave were employed to synthesize starch-protein-gum compound, the process conditions, physical and chemical properties and the functionalities of the compounds were studied, then provided some technique bases for industrialization.Free amino was measured by o-phthaldialdehyde assays( OPA). Then taking the consumptions of the free amino in the samples as an index, single factor tests were done to compare effects of dry-process and wet-process on the synthesizing of starch-protein-gum compound. The optimum conditions of starch-protein-gum compound were optimized by single factor tests and regression design tests.We tested the starch-protein-gum compound's basic chemical index, analyzed it using UV-vis, infrared, fluorescence and polyacrylamide gel electrophoresis and analyzed its shape and structure through scanning electron microscope and particle analysis.Different factors that influence the rheological properties of the starch-protein-gum compound were studied by rheometer. The effect of different factors on the gelling of the starch-protein-gum compound were also studied by rheometer, too. The results showed, the pH value, ionic strength, heat-treatment and the concentration of sucrose can influence the rheological characteristics and gelling texture of the compound.The solubility, emulsifying property and antioxidation of the starch-protein-gum compound were determined. The results showed that the compound had good solubility, emulsifying property and antioxidation. The bread quality improved when the starch-protein-gum compound was added to the bread.