碱热改性米渣谷蛋白对W/O/W型双重乳液稳定性的影响

目的：实现米渣谷蛋白在乳浊体系中的应用。方法：选取碱热改性米渣谷蛋白和span80，采用一步乳化法制备W/O/W型双重乳液，并考察蛋白浓度对双重乳液稳定性的影响。结果：当蛋白质量分数从0.5%升高至2.5%时，乳液大粒径峰消失，显微结构中液滴的双重结构增强，表观黏度及黏弹性提高，离心稳定性和贮藏稳定性增强。当蛋白质量分数为2.5%时，离心后乳清析出指数从37.21%降至10.56%，分层时间从6 h延长至96 h。蛋白质与span80形成复合膜共同稳定油水界面，形成中间态液滴，当界面蛋白足以形成刚性界面膜时，液滴从中间态转为稳定的双重结构；当蛋白质量分数为3.0%时，双重乳液发生絮凝使大粒径峰重新出现，稳定性下降，离心后乳清析出指数为16.48%，制备后96 h左右分层，过剩的蛋白质一部分参与内相液滴的构建，另一部分单独形成O/W型液滴吸附于大体积液滴外侧。结论：一步乳化法下，蛋白质量分数为2.5%时，可制得稳定双重乳液。

Effects of alkali-heat-modified rice residue glutenin on stability of W/O/W double emulsions

Objective: To achieve the application of rice dreg glutelin in emulsions system. Methods: This paper selected alkali-heat modified rice dregs glutenin and span80 as emulsifiers to prepare W/O/W double emulsions by one-step emulsification method, and investigated the effect of protein concentration on the stability of double emulsions to provide the theoretical reference for the preparation of stable double emulsions by one-step emulsification. Results: When the protein mass fraction increased from 0.5% to 2.5%, the large particle size peak disappears in emulsion, the apparent viscosity and viscoelasticity of emulsions were improved, the centrifugal stability and storage stability were enhanced, enhanced dual structure of droplets in microstructure. When the protein mass fraction reached 2.5%, after centrifugation, the whey precipitation index decreased from 37.21% to 10.56%, and the layering time was extended from 6 hours to 96 h. Protein and span80 formed a composite membrane to jointly stabilize the oil-water interface, and formed an intermediate droplet. When the interface protein was enough to form a rigid boundary facial mask, the droplet changed from the intermediate state to a stable dual structure. When the protein mass fraction reached 3.0%, the flocculation of the double emulsions led to the reappearance of the large particle size peak, and the stability was reduced. After centrifugation, the emulsion index was 16.48%, and about 96 hours after preparation, the excess protein was partially involved in the construction of the internal phase droplets, and the other part was separately formed into W/O droplets and adsorbed on the outside of the large volume droplets. Conclusion: Under one-step emulsification method, when the protein content is 2.5%, stable double emulsions can be prepared.