Guo Fengxian, Mao Yiming, Chen Yujie, Wu Shiying, He Zhiyong, Wang Baobei, Chen Hongbin, Wu Shunhong, Zheng Zongping
Fujian Province Key Laboratory for Development of Bioactive Material from Marine Algae, College of Oceanology and Food Science, Quanzhou Normal University, Quanzhou 362000, China.
College of Material Engineering, Fujian Agriculture and Forestry University, Fuzhou 350108, China.
Foods. 2025 Jun 8;14(12):2028. doi: 10.3390/foods14122028.
The solubility of soybean isolate protein (SPI) undergoes significant degradation during storage and transportation. This study investigates the formulation and assessment of SPI-stabilized medium internal phase emulsions (MIPEs) with different solubilities, namely SPI80, SPI70, SPI60, and SPI50, corresponding to solubility levels of about 80%, 70%, 60%, and 50%, respectively. The contact angles of these SPI variants ranged from 79.35 to 86.55 degrees, with SPI60 and SPI50 exhibiting significantly higher values compared to SPI80 and SPI70. All SPI samples were successfully utilized for the preparation of MIPEs. However, as SPI solubility decreases, emulsion stability progressively declines, accompanied by a reduction in the absolute value of zeta potential. Additionally, interfacial protein adsorption in emulsions decreases with decreasing SPI solubility, a trend that is similarly observed in viscosity characteristics, storage modulus (G'), and loss modulus (G″). Confocal laser scanning microscopy (CLSM) and cryo-scanning electron microscopy (Cryo-SEM) analyses revealed that emulsions exhibit reduced uniformity and a less interconnected microstructural network as SPI solubility decreases. These findings provide a theoretical foundation for utilizing low-solubility SPI in MIPEs applications.
大豆分离蛋白（SPI）的溶解度在储存和运输过程中会发生显著降解。本研究调查了具有不同溶解度的SPI稳定的中相乳液（MIPEs）的配方和评估，即SPI80、SPI70、SPI60和SPI50，其溶解度水平分别约为80%、70%、60%和50%。这些SPI变体的接触角范围为79.35至86.55度，与SPI80和SPI70相比，SPI60和SPI50表现出显著更高的值。所有SPI样品均成功用于制备MIPEs。然而，随着SPI溶解度的降低，乳液稳定性逐渐下降，同时zeta电位的绝对值也降低。此外，乳液中的界面蛋白吸附随着SPI溶解度的降低而减少，这一趋势在粘度特性、储能模量（G'）和损耗模量（G''）中也有类似观察。共聚焦激光扫描显微镜（CLSM）和冷冻扫描电子显微镜（Cryo-SEM）分析表明，随着SPI溶解度的降低，乳液的均匀性降低，微观结构网络的连通性也降低。这些发现为在MIPEs应用中利用低溶解度SPI提供了理论基础。
