Department of Nutrition & Food Science, University of Maryland, College Park, Maryland 20742, United States.
College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, P.R. China.
Langmuir. 2021 May 11;37(18):5617-5626. doi: 10.1021/acs.langmuir.1c00484. Epub 2021 Apr 29.
A stable water-in-water (W/W) emulsion was formed by mixing dextran and hydroxypropyl methylcellulose (HPMC) with addition of β-lactoglobulin (Blg) microgels. The microstructure and stability of the W/W emulsion were investigated under different conditions. The microgels accumulating at the liquid-liquid interface led to a stable emulsion at pH 3-5, where the microgels carried positive charges. When the pH was increased above the pI of microgels (∼pH 5), the emulsion was destabilized because the microgels tended to stay in the continuous phase (i.e., dextran) rather than at the interface. The HPMC-in-dextran emulsions were stable under ionic strength levels up to 300 mM. The HPMC-in-dextran emulsion stabilized by Blg microgels was thermally stable, and the heat treatment promoted partial Blg microgel particle-particle fusion on the surface of HPMC droplets at 90 °C. Electrostatic and hydrophobic interactions between dextran and HPMC phase were further investigated to understand the microgels' accumulation at the liquid-liquid interface.
通过混合葡聚糖和羟丙基甲基纤维素（HPMC）并添加β-乳球蛋白（Blg）微凝胶，形成了一种稳定的水包水（W/W）乳液。在不同条件下研究了 W/W 乳液的微观结构和稳定性。在 pH 3-5 下，微凝胶带正电荷，在液-液界面处聚集，导致乳液稳定。当 pH 高于微凝胶等电点（约 pH 5）时，由于微凝胶倾向于留在连续相（即葡聚糖）而不是界面处，乳液会失稳。在离子强度高达 300 mM 的情况下，HPMC-葡聚糖乳液稳定。由 Blg 微凝胶稳定的 HPMC-葡聚糖乳液具有热稳定性，在 90°C 下热处理促进了 HPMC 液滴表面部分 Blg 微凝胶颗粒-颗粒融合。进一步研究了葡聚糖和 HPMC 相之间的静电和疏水相互作用，以了解微凝胶在液-液界面处的聚集。
