Fabrication of Sodium Alginate/Inulin Synbiotic Beads for Protection and Delivery of Lactobacillus plantarum in Storage and Simulated Gastrointestinal Conditions

In this study, sodium alginate/inulin (SA/IN) composite beads were fabricated using the calcium ion cross-linking method, which encapsulated Lactobacillus plantarum to provide it with resistance in a gastrointestinal environment. The results showed that the SA/IN solution functioned as a kind of pseudoplastic fluid, and the storage modulus (G′) and loss modulus (G″) values exhibited a trend of frequency dependence. The diameter, water content, swelling rate, water holding capacity (WHC), and hardness of the composite beads were regulated by IN concentration, with IN making the beads rougher at first and then giving them a more regular shape as the concentration increased. The highest Lactobacillus plantarum encapsulation efficiency reached 92.8 ± 4.14%, and SA/IN beads improved the stability of Lactobacillus plantarum under 4 °C storage and heat treatment. The quantity of Lactobacillus plantarum reached 1.3 ± 0.01 CFU/g, which is close to the quantity observed before digestion. This study confirmed that SA/IN composite beads can serve as a protective carrier of Lactobacillus plantarum with prebiotic activity and can be used in functional food ingredients.