Exploring the impact of thermal convective drying behaviours on intestinal-targeted delivery of viable probiotics encapsulated with Eudragit® L100-trehalose

Spray drying microencapsulation has emerged as a promising technique for producing highly active probiotic powders. The efficient delivery of live probiotics to their target site, particularly the intestinal tract, is crucial for their therapeutic effectiveness. This study aimed to investigate the intestinal-targeted delivery function of particles containing Lactobacillus rhamnosus GG, trehalose and Eudragit® L100 (L100) under various thermal convective drying conditions. The particle drying history, component migration within particle, and the microstructures of the final particles were thoroughly analysed. Our findings demonstrate that temperature and flow rate significantly influence the migration behaviours of trehalose and L100 within the droplets, subsequently impacting the substance distribution on the surface of the final particles. Notably, higher temperatures and flow rates promote the deposition of L100 on the particle surface, leading to enhanced intestinal-targeted delivery function. Cells encapsulated in spray-dried powders containing L100 and produced at 160 °C exhibited higher survival rate and bioaccessibility during simulated gastrointestinal digestion, compared to those obtained at 140 and 120 °C. This study provides insight into the thermal convective drying behaviours and intestinal-targeted delivery function of L100-Tre-LGG particles. It contributes to the field of probiotic delivery and holds significant potential for improving therapeutic outcomes in various applications.