酯化大豆蛋白-壳聚糖复合物乳化性及抑菌性

Emulsifying and bacteriostatic properties of esterified soybean protein-chitosan complex

摘要:

以酯化大豆蛋白和壳聚糖为原料，按照酯化大豆蛋白与壳聚糖质量比为1∶0.1，将酯化大豆蛋白与壳聚糖溶液混合并常温搅拌3 h，制得酯化大豆蛋白-壳聚糖复合物。探讨了pH 5.0下酯化大豆蛋白-壳聚糖复合物的功能性质。采用红外光谱和荧光光谱研究了酯化大豆蛋白-壳聚糖复合物的结构，探讨了酯化改性协同壳聚糖复合改性对复合物乳化性和抑菌性的影响。结果表明，氢键参与了酯化大豆蛋白-壳聚糖复合物的形成过程；在pH 5.0下，相较于酯化大豆蛋白，酯化大豆分离蛋白-壳聚糖复合物（MSPI-CS）、酯化大豆球蛋白-壳聚糖复合物（M11S-CS）、酯化β-伴大豆球蛋白-壳聚糖复合物（M7S-CS）的乳化活性分别提升至10.8 m2/g、9.0 m2/g、12.0 m2/g，乳化稳定性分别提升至88.9 min、71.4 min、95.4 min；MSPI-CS、M11S-CS、M7S-CS对大肠杆菌、金黄葡萄球菌和沙门氏菌的抑菌圈直径均增加；以MSPI-CS、M11S-CS、M7S-CS为乳化剂制备乳液，乳液的平均粒径降低至255.2 nm、315.6 nm、253.6 nm，Zeta-电位绝对值提升至22.07 mV、20.68 mV、22.33 mV，同时乳液存储稳定性提高。

Abstract:

Using esterified soybean protein and chitosan as raw materials, according to the mass ratio of esterified soybean protein and chitosan as 1∶0.1, the esterified soybean protein and chitosan solution were mixed and stirred at room temperature for 3 h to prepare esterified soybean protein. The functional properties of esterified soy protein-chitosan complexes were investigated under pH 5.0 conditions. The structure of esterified soybean protein-chitosan complex was studied by infrared spectroscopy and fluorescence spectroscopy, and the effect of esterification modification and chitosan complex modification on the emulsification and antibacterial properties of the complex was discussed. The results show that hydrogen bonds are involved in the formation of esterified soybean protein-chitosan complexes; at pH 5.0, compared with esterified soybean protein, the emulsifying activity of esterified soybean protein isolate-chitosan complex (MSPI-CS), esterified glycinin-chitosan complex (M11S-CS), esterified β-conglycinin-chitosan complex (M7S-CS),were increased to 10.8 m2/g, 9.0 m2/g, 12.0 m2/g, and the emulsion stability were increased to 88.9 min, 71.4 min, and 95.4 min, respectively; The inhibition zone diameters of MSPI-CS, M11S-CS, M7S-CS against Escherichia coli, Staphylococcus aureus and Salmonella all increased; emulsions were prepared with MSPI-CS, M11S-CS, and M7S-CS as emulsifiers, the average particle size of the emulsions decreased to 255.2 nm, 315.6 nm, and 253.6 nm, and the absolute values of Zeta-potentials increased to 22.07 mV, 20.68 mV, and 22.33 mV. At the same time, the storage stability of the emulsion is improved.