为了研究在乙醇存在及不同透析时间下丝素蛋白的结构及功能特性，通过扫描电镜（SEM）、傅立叶红外光谱（FT-IR）、表面张力、乳化性、乳化稳定性、起泡性、起泡稳定性及蛋白溶解性进行测定。FT-IR分析表明当溶剂中添加乙醇后，样品中β-折叠结构明显增加。SEM分析表明CaCl2-CH3CH2OH-H2O体系处理的丝素蛋白较CaCl2-H2O体系溶解更为完全。随透析时间的延长，CaCl2-CH3CH2OH-H2O体系处理的丝素蛋白的最低表面张力值和临界胶束浓度均低于CaCl2-H2O体系。此外，CaCl2-CH3CH2OH-H2O体系处理的丝素蛋白液在透析20 h左右的乳化性最好，约为97.51%，15 h左右乳化稳定性最好,起泡性约为355.49%，泡沫稳定性在10 h左右最好；而CaCl2-H2O体系处理的丝素蛋白液在透析25 h左右乳化性最好，约为96.23%，20 h左右的乳化稳定性最好，起泡性约为200.86%，泡沫稳定性在15 h左右最好。因此，乙醇的加入可有效改善丝素蛋白结构和功能特性，为丝蛋白质基表面活性剂的开发提供理论依据。

In order to study the structural characteristics and functional properties of silk fibroin in the presence of ethanol, scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) were used to measure surface tension, emulsifying properties, emulsion stability, foaming properties, foam stability, and protein solubility. The FT-IR spectra indicated a significant increase in the β-sheet structures of the silk fibroin sample after the addition of ethanol to the solvent system. The SEM analysis showed that the silk fibroin was dissolved more completely in the calcium chloride-ethano-water (CCEW) system than in the calcium chloride-water (CCW) system. With increasing dialysis time, the lowest surface tension and critical micelle concentration of the silk fibroin in the CCEW system were much lower than those in the CCW system. In addition, for the CCEW system-treated silk fibroin solution, the best emulsifying property (about 97.51%), emulsion stability (about 355.49%), and foam stability were achieved after dialysis times of 20, 15, and 10 h, respectively. For the silk fibroin solution treated with CCW system, the best emulsifying property (96.23%), emulsion stability (about 200.86%), and foam stability were achieved after dialysis times of 25, 20, and 15 h, respectively. Therefore, the addition of ethanol can effectively improve the structural and functional properties of silk fibroin, and this research could provide a theoretical basis for the development of silk protein-based surfactants.

广西科学研究与技术开发计划项目（桂科能14122009-3-3；桂科转12125006-30）；国家科技型中小企业技术创新项目（14C26214502814）