Optimization of probiotic nanoencapsulation using advanced microfluidic technologies to produce monodisperse nanostructures with thermal stability and targeted release in complex dairy matrices

The integration of advanced microfluidic technologies in the nanocapsulation of probiotics represents a transformative approach to fabricating monodisperse nanostructures with exceptional thermal stability, tailored release kinetics, and compatibility with complex dairy matrices. This study leverages high-precision microfluidic platforms, characterized by microchannel geometries with hydraulic diameters of ۵۰-۱۰۰ μm and controlled flow regimes (Reynolds number < ۱), to synthesize uniform nanocapsules encapsulating Lactobacillus acidophilus and Bifidobacterium bifidum. Utilizing a T-junction microfluidic device, sodium alginate (۲% w/v) and chitosan (۰.۵% w/v) were employed as biocompatible polymers, with droplet formation driven by hydrodynamic focusing at aqueous-to-oil phase flow rate ratios of ۱:۱۰. Ionic crosslinking with calcium chloride (۰.۱ M) and secondary chitosan coating yielded nanocapsules with a mean diameter of ۱۵۰ ± ۱۰ nm and a polydispersity index of ۰.۱۲, as confirmed by dynamic light scattering. These nanostructures exhibited superior thermal stability, retaining ۹۰% probiotic viability after ۳۰ minutes at ۶۵°C, attributed to the synergistic protective effects of the alginate-chitosan matrix against thermal denaturation and oxidative stress. In vitro evaluation under simulated gastrointestinal conditions revealed robust gastric resistance, with less than ۱۰% probiotic release in pH ۲.۰ over ۲ hours, followed by ۸۵% release in pH ۷.۴ intestinal fluid within ۴ hours, demonstrating pH-responsive targeted delivery. Incorporation into dairy matrices, specifically yogurt (pH ۴.۵, ۴% fat) and cheddar cheese (pH ۵.۲), maintained probiotic viability at ۱۰^۸ CFU/mL after ۲۸ days of storage at ۴°C, despite mechanical and osmotic stresses during processing. Advanced characterization, including zeta potential analysis (-۲۵ mV) and Fourier-transform infrared spectroscopy, confirmed the structural integrity and chemical stability of the nanocapsules. Comparative analysis with conventional emulsification techniques highlighted the microfluidic approach's ability to reduce polydispersity by ۶۵% and enhance encapsulation efficiency by ۳۰%. These findings underscore the potential of microfluidics to revolutionize probiotic delivery in functional foods, enabling precise modulation of nanocapsule morphology and functionality. The scalability of this approach, coupled with its adaptability to personalized nutrition, positions it as a cornerstone for next-generation food engineering, with implications for optimizing gut microbiome health and developing tailored dairy-based nutraceuticals.

کلیدواژه ها:

Microfluidics ، Nanocapsulation ، Probiotics ، Monodisperse Nanostructures ، Thermal Stability ، Targeted Release ، Dairy Matrices ، Sodium Alginate