Abstract:To improve the heat resistance of Lactobacillus reuteri, maltodextrin and phospholipid were used as composite wall materials. These constituents were embedded to encapsulate L. reuteri, resulting in the formation of liquid microcapsules. The results showed that, as the concentrations of phospholipids and maltodextrin increased and the emulsification time was prolonged, the encapsulation efficiency, EAI, ESI, and absolute potential values of microcapsules demonstrated a trend of first increasing and then decreasing (P<0.05). Concurrently, the average particle size demonstrated a trend of first decreasing and then increasing (P<0.05). The optimal preparation process for the microcapsules, obtained through response surface design, was as follows: 14.83% (m/m) phospholipid, 15% (m/m) maltodextrin, emulsification time of 86.39 minutes, and embedding rate of 99.11%. The number of viable bacteria in the L. reuteri microcapsules was significantly increased after heat treatment (P<0.05). In vitro simulated digestion experiments showed that, during the gastric digestion stage, the number of viable bacteria gradually increased over time (P<0.05), and after 2 h, the quantity of viable bacteria in the microcapsules reached 1.85×108 colony-forming units/mL. In conclusion, liquid microcapsules of L. reuteri prepared using the composite wall material of maltodextrin and phospholipid demonstrated a good embedding effect, and they improved the heat resistance and gastrointestinal survival rate of L. reuteri. These data provide a theoretical basis for the production and application of L. reuteri.
