Influence of polysaccharide-based co-encapsulants on efficiency, stability, and release of vitamins B12 and D3 in multilayered microcapsules

This study developed co-loaded vitamin B12 (vitB12) and D3 (vitD3) solid microcapsules using W1/O/W2 emulsions, followed by spray-drying. The effects of four polysaccharide-based gels as co-encapsulants on the microcapsules' morphological characteristics, encapsulation efficiency, storage stability, and gastrointestinal simulation were explored. The electrostatic bonding with chitosan in W1 and multilayer protection from the W1/O/W2 structure cause the high encapsulation efficiency of vitB12 (88.3 ± 0.8%–92.7 ± 1.1%). Further, adding polysaccharides into W2 improved the particle integrity of the dried powders and enhanced the retention rate and encapsulation efficiency of vitamins. Stability testing revealed that the encapsulation matrix incorporating sodium carboxymethylcellulose provided the best protection for vitB12 (plateau values of 97.8 and 95.8% at 25 and 40 °C, respectively) and lower degradation rates for vitD3 (decay constants kD of 0.26 and 0.49%/day). The formulation containing sodium alginate exhibited a controlled release of core components under simulated gastric conditions and the highest cumulative release (91.1 ± 5.3% vitB12 and 81.9 ± 3.6% vitD3) under simulated intestinal conditions. Our study suggests that the co-encapsulation strategy using the W1/O/W2 structure and spray-drying can be utilised to obtain good commercial products containing hydrophilic and lipophilic components, and polysaccharides as co-encapsulants can effectively regulate the chemical stability and release behaviour of the encapsulated components.