Fabrication of synbiotic carbohydrate polymer-based microcapsules: Effect of prebiotics on probiotic viability during freeze-drying, gastrointestinal transit and storage

Abstract

The stability and efficacy of probiotics can be significantly enhanced through advanced encapsulation technologies. This study aimed to investigate the impact of co-encapsulating probiotic with prebiotics in chitosan coated–alginate/gellan gum microcapsules on their viability during freeze-drying, gastrointestinal transit, and storage. Five prebiotics were added to microcapsules to assess their impact on probiotic viability during freeze-drying, including inulin, fructo-oligosaccharide (FOS), galacto-oligosaccharide (GOS), xylo-oligosaccharide (XOS), and resistant dextrin (RD). Notably, FOS–integrated microcapsules at concentration of 4 wt% exhibited the highest stability, achieving 83.36 % probiotic survival rate post-freeze-drying, a 28 % increase over those without FOS. Physicochemical analysis revealed that 4 % FOS–integrated microcapsules exhibited a particle size of 523.53 μm, a pore size of 17.2 μm, a moisture content of 3.57 %, and aw of 0.246, contributing to enhanced probiotic retention. The addition of FOS maintained probiotic viability at ∼6.4 log CFU/g after gastrointestinal digestion, following Korsmeyer–Peppas release kinetics (R2 = 0.9035). Additionally, these microcapsules sustained probiotic levels (> 6 log CFU/g) for 90 days at 4 °C and 7 days at 25 °C, highlighting their long-term storage potential. These findings provide valuable insights into designing resilient synbiotic-microcapsules for functional foods, supplements, and therapeutic applications, ensuring enhanced probiotic stability and efficacy under real-world conditions.