摘要
Bifidobacterium faces major challenges in the gastrointestinal tract, including inactivation under acidic conditions and insufficient targeted release. In this study, three novel heterologous dual-protein complex systems were constructed by lactoferrin (LF) with α-lactalbumin (ALA), β-lactoglobulin (BLG), casein (CN). Subsequently, sodium alginate (SA) -cross-linked gel microcapsules loaded with these dual-protein complexes and B. animalis F1-7. The optimal preparation conditions for the dual-protein were as follows: ALA/LF = 1.5, 50 °C; BLG/LF = 2, 50 °C; CN/LF = 0.5, 25 °C. Incorporation of SA and endogenous emulsification method enabled efficient encapsulation of B . animalis F1-7, achieving encapsulation efficiency exceeding 90%. B. animalis F1-7@SA-(LF-ALA/BLG/CN) exhibited strong acid resistance, favorable intestinal responsiveness, and significantly improved microbial viability. The microcapsules enhanced gastric acid tolerance primarily through a spatial barrier effect, while the incorporation of dual-protein components contributed to matrix structural reinforcement and digestion-responsive release behavior. This integrated “physical protection-structural modulation” strategy also conferred excellent 28-day storage stability. In vitro experiments by mice/human feces, combined with 16S rRNA and metabolomics analysis, revealed that the composite microcapsules effectively regulated the structure of the microbial community and altered metabolite profiles (e.g. , pathways involved in nitrogen metabolism). Overall, this study provided reproducible preparation parameters and a theoretical basis for SA-based dual-protein composite encapsulation delivery systems, and offered a promising strategy to address the coordinated challenges of activity, controlled release, and storage stability of sensitive food bioactive microorganisms or nutrients.
危险品化学品经营许可证（带存储）