Viability of the Microencapsulation of Lactobacillus casei TISTR 390 Containing Inulin in Simulated Gastrointestinal Conditions and Storage

Abstract

This research aimed to determine the process condition for microencapsulation of Lactobacillus casei TISTR 390 by spray drying with maltodextrin and inulin as the coating agent. The physical properties and survivability of the microencapsulated cell were evaluated under simulated gastrointestinal conditions and during storage. Firstly, 3 inlet temperatures (150, 160 and 170 ºC) and 3 maltodextrin levels (5, 10 and 15 % (w/v)) were examined. The result reveals that an optimum condition was at 160 ºC inlet temperature with 15 % maltodextrin. Subsequently, inulin was added in 3 combinations; T1 (15 % maltodextrin and 5 % inulin (w/v)), T2 (10 % maltodextrin and 10 % inulin (w/v)) and T3 (5 % maltodextrin and 15 % inulin (w/v)) in an effort to generate synbiotic powder products. The best result was observed with a combination of 10 % maltodextrin and 10 % inulin. The obtained powder had a moisture content of 1.5±0.01 %, a water activity of 0.28±0.02, a total density of 0.71±0.04 g/mL, a solubility of 84.71±0.01 %, and a lactobacilli survival rate after spray drying of 90.76 %. The microencapsulated lactobacilli containing inulin powders were able to survive in acidic (pH 2) and bile salt solution (2 % w/v) after 120 min of incubation time with more than 60 % of the cell surviving. Furthermore, the microencapsulated powders were kept in aluminum-laminated bags at room temperature for 6 weeks and it was found that the cell viability remained at 6 log CFU/g. Therefore, a combination of an equal weight of maltodextrin and inulin was a promising protection agent for L. casei TISTR 390 in the simulated gastrointestinal conditions and during storage at ambient temperature. HIGHLIGHTS Microencapsulation probiotic bacteria with prebiotic by spray drying method contribute the synbiotic microcapsule Microencapsulaiton with an equal weight of maltodextrin and inulin was promising as a protective agent to serve the survival in the gastrointestinal tract and during storage The synbiotic microcapsule can survive at room temperature for up to 6 weeks in an aluminum-laminated bag.