Plant-based products represent promising alternatives to animal-derived foods, offering solutions to health and environmental challenges. This study evaluates the lipid-lowering effects of fermented walnut milk and elucidates its underlying mechanisms using a high-fat diet (HFD)-induced obesity mouse model. Results demonstrated that fermented walnut milk significantly improved the physical (food intake, body weight, fat index) and biochemical indicators (blood lipid profiles, liver damage biomarkers) compared to animal-based fermented milk in HFD mice. It effectively alleviated pathological changes in the liver and adipose tissue, while enhancing intestinal mucosal integrity in the colon and ileum. Moreover, fermented walnut milk markedly reshaped gut microbiota by increasing the abundance of beneficial bacteria (Dubosiella, Romboutsia, Lactobacillus, Bifidobacterium, etc.), negatively associated with obesity, and decreasing harmful bacteria (Faecalibaculum, Erysipelotrichaceae, Acetatifactor, etc.), positively correlated with obesity. Additionally, it significantly elevated short-chain fatty acid levels (acetic acid, isohexanoic acid, hexanoic acid). In conclusion, fermented walnut milk emerges as a promising functional plant-based product for mitigating obesity and gut microbiota dysbiosis induced by a high-fat diet, providing new insights for dietary intervention strategies.

In order to study the correlation between emulsion properties and microencapsulation rates and surface oil contents under different homogenization and sterilization conditions, the effects of emulsion stability, particle size, and particle size distribution on microencapsulation efficiency under different conditions were measured using a LUMiSizer 611 dispersion analyzer, and the morphological properties and storage stability of microcapsules under optimal conditions were analyzed. The results showed that the homogenization pressure and temperature and the sterilization conditions that provided the smallest emulsion stability index and average particle size were 40 MPa, 65 ℃ and 85 ℃/15 min, respectively. Under these conditions, particle size distribution was less scattered, and encapsulation rates of 95.38%, 97.12% and 94.23% were obtained, respectively. The average particle size of walnut oil microcapsules was 6.62 μm, with a surface oil content of 1.03% and an encapsulation rate of 96.41%. The surface and internal structure of the microcapsules were found to be good by scanning electron microscopy (SEM) indicating good encapsulation efficiency. Under accelerated storage conditions, walnut oil microcapsules showed better stability than free walnut oil. After 35 days of storage under different conditions, the reduction in the retention rate of walnut oil microcapsules varied, and the highest retention rate was achieved under the conditions of low temperature, darkness, and no oxygen or low oxygen concentration. This study could provide a theoretical basis for the selection and application of homogenization and sterilization processes for walnut oil emulsion and microcapsule products.