Study On Functional, Properties And Structure Characterization Of Rice Protein-Dextran Complex

Rice protein is recognized as a good vegetable protein with hypoallergenic characteristics. However, the application of rice protein in food industry is limited due to its poor solubility in water. In the present study, rice protein-dextran complex was prepared, and its properties and structure characterization were evaluated.Rice protein-dextran complex was prepared by maillard reaction in aqueous solution. And the effects of reaction temperature, time, pH, rice protein concentration, the ratio of rice protein and dextran on the grafting degree of rice protein-dextran complex were studies. The optimum condition of the preparation of rice protein-dextran complex was obtained as follow:rice protein concentration4.5mg/mL、the ratio of rice protein and dextran5.0, at80℃for21min. The graft degree of the complex was44.97%。The properties of rice protein-dextran complex were also evaluated. The properities of rice protein-dextran complex, such as solubility, emulsion stability and form stability were improved obviously, in a manner of grafting degree dependence. But both emulsifying and form properties showed an trend of first increase and then decrease as the grafting degree increased. Compared with rice protein, rice protein-dextran complex has a better thermal stability.SDS-PAGE showed that five bands intensities in rice protein decreased or disappeared, followed with the appearance of new band at high molecular weight. Amino acid analysis suggested that the major locus during Maillard reaction contained arginine and lysine. In addition, the surface hydrophobicity of rice protein-dextran complex was increased, while the content of free sulfhydryl group was decreased.