Assessment the viability of encapsulated lactobacillus casei by qodume shirazi (Alyssum homolocarpum) seed mucilage and inulin in simulated gastric juice and bile solution

Abstract

Introduction: Nowadays, due to the people’s awareness level to functional food effectiveness, much of the food market is dedicated to this group. Food with probiotic bacteria attracts the major proportion to itself. On the definatia, the probiotic food should have 106-107 CFU/g to confer useful effects to the host. Microencapsulation technology is one of the recommended methods for protection of probiotics against processing harsh condition, gastrointestinal tract and storage. Simulation of the effect of stresses on probiotic microcapsules seems necessary, to estimate how resistant to these harsh conditions and how long they can be stored. Therefore, choosing the best wall materials is necessary. Materials and methods: In this research, the RSM method, box-behnken plan was used to survey the effect of inulin (0, 1.5,3%), alyssum homolocarpum seed mucilage (0, 0.3, 0.6%) and spray dryer inlet temperature (90-95-100 ˚C) on survivability of bacteria, during 3 months storage in 4 and 25 ˚C and in simulated gastric juice and bile condition. Results: The highest and lowest survivability after spray-drying, was reported 82.23 and 38.04% respectively. The highest cell reduction after 3 months storage in 25 and 4 ˚C was reported 0.99 and 0.25 (Log cfu/g) for tretment14 (inulin 0%-seed mucilage 0%- inlet temperature 95 ˚C), and the lowest cell reduction was reported 0.9 and 0.15 (Log cfu/g) for treatment 9 ( inulin 3%-seed mucilage 0.6%- inlet temperature 95 ˚C) after 3 months storage in 25 and 4 ˚C. as well as, the size, morphology and moisture content of the microcapsules was surveyed. The results showed that inlet temperature had no significant effect on survivability after drying and in simulated gastric juice and bile condition (p>0.05). Results showed, inulin and seed mucilage had significant effect on the survivability after drying, during storage in 25 and 4 ˚C, and in bile condition (p<0.05). Seed mucilage had no significant effect on the survivability during gastric juice condition (p>0.05). The moisture of all samples were (> 4%) that is recommended for probiotic storage. The size and morphology of particles were measured by scan electron microscopy and showed spherical and uniform particles, some of them were dented or had hollowed in center. The average size of microcapsules was 2.58-25.3μ. All in all, the results showed microencapsulation with inulin and alyssum homolocarpum seed mucilage can protect the L.casei during thermal and gastrointestinal harsh conditions. It was found this method can be considered as one of the solutions for increasing the survivability of the mentioned probiotic.