Survival of encapsulated probiotic bacteria in Iranian yogurt drink (doogh) after the product exposure to simulated gastrointestinal conditions.

摘要

Microencapsulation of probiotic cells with hydrocolloids, as an efficient method for improving survival of probiotics in foods, has received special interest and investigation. This study, examined the protective effect of microencapsulation with calcium alginate on survival of probiotic cells (Lactobacillus acidophilus La-5 and Bifidobacterium lactis Bb-12) in an Iranian yoghurt drink (doogh) following exposure to simulated gastrointestinal conditions. The 3 simulated gastrointestinal conditions were: reinforced/strict gastrointestinal conditions (pH 1.5 for 90 min/2% bile for 90 min), semi-alleviated gastrointestinal conditions (pH 1.5 for 90 min/1% bile for 90 min) and real-alleviated gastrointestinal conditions (pH2.0 for 30 min/0.6% bile for 60 min). The viability of free probiotic cells increased from 0.6 and 0.2% for L. acidophilus and bifidobacteria, respectively, to 18.0 and 9.5%, respectively, under reinforced gastrointestinal conditions after encapsulation. Under real-alleviated conditions, cell survival rates were 16.1% for L. acidophilus and 21% for bifidobacteria before encapsulation, and these values increased to 26.3 and 34.0% for L. acidophilus and bifidobacteria, respectively, after encapsulation.