Zhao Guilan, Wang Shengnan, Yang Lina, Wang Peng, Han Lu, Liu He
College of Food Science and Technology, Bohai University, Jinzhou 121013, China.
College of Food Science and Technology, Bohai University, Jinzhou 121013, China.
Food Chem. 2025 Apr 15;471:142804. doi: 10.1016/j.foodchem.2025.142804. Epub 2025 Jan 6.
To enhance the surface hydrophobicity and emulsification capacity of silica colloidal particles, a natural surface modification of soy hull polysaccharides (SHP) was conducted. Here, the effects of pH and ionic strength on the stability, microstructure and rheological properties of concentrated Pickering emulsions were investigated. Experimental results show emulsions gelled at pH 2, with increasing pH (2-10), SiO-SHP absolute zeta potential (from -19.6 to -44.7 mV) and interfacial tension (from 15.2 to 25.09 mN/m) increased, and viscosity, viscoelasticity and storage stability decreased. Additionally, at low NaCl concentrations (<150 mM), SiO-SHP interfacial tension remained low (21.3 mN/m), promoting stable emulsions (TSI < 1.5). In this case, the electrostatic interaction was slightly affected by ions, facilitating the occurrence of composite coagulation. However, as ionic concentration increased (150-300 mM), interfacial tension increased (from 20.5 to 27.6 mN/m). Thus, our study presents important insights into the pH and salt ions dependent mechanism of emulsion stabilization by SiO-SHP.
为提高二氧化硅胶体颗粒的表面疏水性和乳化能力，对大豆壳多糖（SHP）进行了天然表面改性。在此，研究了pH值和离子强度对浓Pickering乳液的稳定性、微观结构和流变学性质的影响。实验结果表明，乳液在pH值为2时凝胶化，随着pH值升高（2 - 10），SiO - SHP的绝对zeta电位（从 - 19.6到 - 44.7 mV）和界面张力（从15.2到25.09 mN/m）增加，而粘度、粘弹性和储存稳定性降低。此外，在低NaCl浓度（<150 mM）下，SiO - SHP界面张力保持较低（21.3 mN/m），促进乳液稳定（TSI < 1.5）。在这种情况下，静电相互作用受离子影响较小，有利于复合凝聚的发生。然而，随着离子浓度增加（150 - 300 mM），界面张力增加（从20.5到27.6 mN/m）。因此，我们的研究为SiO - SHP对乳液稳定的pH值和盐离子依赖性机制提供了重要见解。
