Synbiotic encapsulation of probiotic Latobacillus plantarum by alginate -arabinoxylan composite microspheres

The probiotic Latobacillus plantarum was encapsulated in microspheres prepared through co-gelation of alginate (SA) and prebiotic arabinoxylan materials (AX), and the stability and survival rate of the probiotic in simulated gastrointestinal conditions were studied. The experimental results showed that the SA and AX were physically entangled to each other in the microspheres in which the AX molecules played a dominant role in probiotic encapsulation. Under simulated small intestinal conditions, a slower release rate of Latobacillus plantarum was observed when water-insoluble AX with the highest content of ferulic acid (1.78 μg/g AX) was used as the AX component in the microspheres. Compared to microspheres formed by alginate alone, the AX-SA composite microspheres significantly improved the encapsulation efficiency (2.5 folds), gastric stability (survival rate from 51.1% to 74.0%) and the bile salt resistance (survival rate from 70.6% to 81.6%). The incorporation of prebiotic arabinoxylan oligosaccharides (AXOS) into the AX-SA microspheres further significantly enhanced the encapsulation efficiency, gastric stability, bile salt resistance, as well as the storage stability. Thus, the co-formed AX-SA-AXOS synbiotic microsphere might be an ideal carrier for target delivery of probiotics.