Fabrication of microcapsules encapsulating L. rhamnosus GG with Eudragit® L100–trehalose and polysaccharides: a study on physicochemical properties and cell adhesion

Our previous study revealed the relationship between the droplet-to-particle transition process and the functionality of Lacticaseibacillus rhamnosus GG (LGG) particles encapsulated with Eudragit® L100 (L100)–trehalose (Tre). The main focus was on exploring the effects of convective drying conditions on the targeted delivery of viable bacteria to the intestine, by using a single droplet drying technique to mimic realistic spray drying conditions. In the current study, spray-dried L100–Tre–LGG microcapsules combined with polysaccharides (maltodextrin, inulin, and soluble soy polysaccharides) were fabricated, to investigate the physicochemical properties of powders and the adhesion ability of spray-dried LGG cells. The results showed that L100–Tre powder exhibited better moisture content (4.84%) and hygroscopicity (17.94%) than the other three powders produced with L100–Tre and polysaccharides. Moreover, the LGG in the powders retained a high viability of 9 log CFU g⁻¹ after spray drying and maintained 7 log CFU g⁻¹ after 8 weeks of storage. Notably, all powders exhibited desirable survival rates of 87.4–93% for LGG after in vitro digestion. In addition, spray drying had minimal impact on the cell adhesion ability of LGG, maintaining an adhesion rate of 80% to Caco-2 cells. The L100–Tre–LGG probiotic spray-dried powders exhibit long shelf stability and strong adhesion capacity, providing strong support for the industrial production of probiotic products.