Recently, the Innovation Team for Plant Protein Structure and Functional Regulation at Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, revealed differences between walnut and peanut protein microgel particles in terms of their preparation, physicochemical characteristics, and applications in emulsion and gel stabilization. The findings were published in Food Chemistry (JCR Q1; impact factor: 10.4). Yingying Gu, a doctoral student enrolled in 2025, and Zhimo Jiang, a master’s student enrolled in 2025, are co-first authors of the paper. Prof. Aimin Shi is the corresponding author.

Microgel particles are swollen polymeric particles with distinctive structural and functional properties. Compared with conventional solid particles and low-molecular-weight surfactants, microgel particles offer considerable advantages in food emulsion systems because of their excellent interfacial stabilization capacity. In this study, peanut protein isolate (PPI) and walnut protein isolate (WPI) were investigated to systematically elucidate their functional differences in microgel particle formation and the underlying mechanisms governing emulsion stabilization and gel formation. The results demonstrated that differences in the hydrophilicity of the two proteins determined the distinct physicochemical properties of their respective microgel particles. Walnut protein microgel particles (WPI-MPs) exhibited greater surface hydrophobicity, and the high-internal-phase emulsions prepared with these particles, containing 75% oil, showed superior stability. In contrast, peanut protein microgel particles (PPI-MPs) were more hydrophilic, and the resulting emulsion gels exhibited greater rheological stability and stronger mechanical properties. The study also demonstrated that the addition of salt ions significantly increased the apparent viscosity and stability of the emulsion gels, with sulfate ions (SO₄²⁻) producing the most pronounced improvement in gel properties. These findings address a gap in current knowledge regarding the structural and application-related properties of walnut protein microgels and provide a theoretical foundation and supporting data for the targeted selection of plant protein resources in the development of emulsion-based and solid gel foods.

This work was supported by the National Key Research and Development Plan, the National Natural Science Foundation of China, and the Agricultural Science and Technology Innovation Project of CAAS.

Original article: https://doi.org/10.1016/j.foodchem.2026.151281