Impact of the microencapsulation method and wall material on the survival of Lactobacillus acidophilus under simulated gastrointestinal conditions

The study aimed to assess the effect of microencapsulation methods and wall material composition on the survival of Lactobacillus acidophilus, both immediately after encapsulation and following exposure to simulated gastrointestinal conditions. Lactobacillus acidophilus was encapsulated by ionic gelation and spray drying using various concentrations of wall materials. Physicochemical and morphological characterizations were performed to analyze changes in wall materials and differences in survival rates. Furthermore, microcapsules were subjected to an in vitro digestion method to assess the probiotic survival rate. For ionic gelation, the optimal wall material composition was 50% sodium alginate, 25% Arabic gum and 25% whey protein isolate, yielding a post-encapsulation survival rate of 94%. For spray drying, the most effective formulation consisted of 80% Arabic gum and 20% whey protein isolate, which also resulted in a 94% survival rate. However, after in vitro simulated gastrointestinal digestion, the survival of Lactobacillus acidophilus was significantly higher in spray-dried microcapsules (36%) compared to those produced via ionic gelation (3%). The novelty of this study lies in preparing capsules containing Lactobacillus acidophilus to be delivered in the intestinal tract for greater health benefits. The higher concentration of reducing sugars relative to peptides indicated that glycolysis was the predominant degradation pathway during digestion. These findings suggest that spray drying offers enhanced protection for Lactobacillus acidophilus, likely due to the formation of a more stable and resistant encapsulation matrix. Consequently, spray drying represents a promising technique for applications in functional food development, supporting improved probiotic viability and potential health benefits.