海藻酸钠添加量对米糠蛋白理化性质和结构特性的影响

Effect of Sodium Alginate Addition Amount on the Physicochemical Properties and Structural Characteristics of Rice Bran Protein

摘要:

该研究通过将海藻酸钠与米糠蛋白复合，研究了不同的海藻酸钠添加量（0 wt.%、15 wt.%、30 wt.%、45 wt.%、60 wt.%、75 wt.%、90 wt.%）对米糠蛋白的理化性质（乳化性、乳化稳定性、起泡性、起泡稳定性、粒度、Zeta电位）和结构特性（内源荧光、表面疏水性、游离巯基、二硫键、傅里叶红外光谱）的影响。结果表明，当海藻酸钠添加量为45 wt.%时，米糠蛋白的乳化性、起泡性和起泡稳定性分别提高了40%、18%和9%，乳化稳定性提高了20倍以上，此时复合物的粒径最小，所带电荷最多。随着海藻酸钠添加量的增加，内源荧光强度降低且发生红移，表面疏水性增强，游离巯基含量提高且二硫键含量降低。此外，傅里叶红外光谱证实海藻酸钠会改变米糠蛋白的二级结构。该研究的结果以期为后续米糠蛋白-海藻酸钠复合物的应用提供理论基础。

Abstract:

In this study, the effects of different sodium algae addition amounts (0 wt.%, 15 wt.%, 30 wt.%, 45 wt.%, 60 wt.%, 75 wt.%, 90 wt.%) on the physicochemical properties (emulsifying property, emulsion stability, foaming capacity, foam stability, particle size, Zeta potential) and structural characteristics (endogenous fluorescence, surface hydrophobicity, free sulfhydryl group, disulfide bond, Fourier transform infrared spectrum) of rice bran protein were investigated by complexing sodium alginate with rice bran protein. The results showed that when sodium alginate was added at 45 wt.%, the emulsifying property, foaming capacity and foaming stability of rice bran protein increased by 40%, 18% and 9%, respectively, and the emulsion stability increased by more than 20 times, with the particle size of the complex being the smallest and the charge carried being the greatest. With the increase of the addition amount of sodium alginate, the intrinsic fluorescence intensity decreased, a red shift occurred, surface hydrophobicity increased, content of free sulfhydryl group increased and content of disulfide bond decreased. In addition, Fourier infrared spectroscopy analysis confirmed that the added sodium alginate change the secondary structure of rice bran protein. The results of this study are expected to provide a theoretical basis for the subsequent application of rice bran protein-sodium alginate complex.