The processing study revealed the physicochemical properties of different microgel particles and their application differences in emulsion and gel systems.

Recently, the Innovative Team for Plant Protein Structure and Functional Regulation of the Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, has revealed the application differences between walnut and peanut protein microgel particles in their preparation, characterization, and the stabilization of emulsions and gels. The relevant research findings have been published in the international academic journal *Food Chemistry* (JCR Q1, IF=10.4). Gu Yingying, a 2025 PhD candidate, and Jiang Zhimo, a 2025 master's student at the Institute, are the co-first authors of the paper, and Professor Shi Aimin from the Institute is the corresponding author.

Microgel particles are a type of swollen polymer particles with specific structural and functional properties. Compared with traditional solid particles and small-molecule surfactants, they exhibit remarkable advantages in food emulsion systems due to their outstanding interfacial stability. In this study, peanut protein isolate (PPI) and walnut protein isolate (WPI) were selected as research objects. The functional differences between the two in the construction of microgel particles were systematically analyzed, and their regulatory mechanisms in stabilizing emulsions and forming gels were thoroughly investigated. The study found that the difference in hydrophilicity between the two proteins determines the distinct physicochemical properties of their microgel particles. Walnut protein microgel particles (WPI-MPs) possess stronger surface hydrophobicity, and the high internal phase emulsions (oil content of 75%) prepared therefrom show superior stability. In contrast, peanut protein microgel particles (PPI-MPs) have strong hydrophilicity, and the emulsion gels prepared using them feature higher rheological stability and better mechanical properties. In addition, the study demonstrated that the introduction of salt ions can significantly increase the apparent viscosity and gel stability of emulsion gels, among which SO₄²⁻ exerts the most prominent effect on improving gel performance. This study fills the research gap regarding the structural and application characteristics of walnut protein microgels, and provides theoretical basis and data support for the precise selection of plant protein resources to develop emulsion-type foods or solid gel foods.

This research was funded by the National Key Research and Development Program of China, the National Natural Science Foundation of China, and the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences.

Original link:https://ifst.caas.cn/xwzx/snyw/65d895d2bf9542d7bfcb59cfe15129e1.htm