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)withα-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℃;BLG/LF=2,50℃;CN/LF=0.5,25℃.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 chal-lenges of activity,controlled release,and storage stability of sensitive food bioactive microorganisms or nutrients.
基金
supported by National Key Research and Development Program of China[grant number 2024YFF1106500]
Natural Science Foundation of Wuhan[grant number 2024040801020285].
