In situ alginate crosslinking during spray-drying of lactobacilli probiotics promotes gastrointestinal-targeted delivery

Alginate-based formulations have shown desirable functional characteristics for probiotic encapsulation. However, current technologies used to produce these formulations are inefficient, detrimental to probiotics viability or do not produce dry, shelf-stable products. Herein, we developed a novel spray-drying technique that combines particle formation, alginate crosslinking and drying into a single step, thereby streamlining the production of encapsulated probiotics powder. Lacticaseibacillus rhamnosus GG (LGG) encapsulated in six encapsulation formulations were characterized and compared. Among the six formulations investigated, the crosslinked alginate with sucrose formulation (Ca-Alg-Suc) was found to be most promising, achieving ~10⁹ CFU/g of surviving LGG after spray-drying and exposure to simulated gastric fluid (SGF). The Ca-Alg-Suc formulation was further evaluated with Lactiplantibacillus plantarum and Lacticaseibacillus paracasei, and similar results of high post-spray-drying and post-SGF viabilities were obtained. Successful encapsulation of different lactobacilli probiotics via the proposed spray-drying technique highlights potential of this procedure to be scaled up for commercial applications.