Effect of lecithin and starch on alginate-encapsulated probiotic bacteria

Abstract

The effect of lecithin and starch on viability of alginate encapsulated probiotics was determined at different temperatures. Probiotic organisms (1% v/v>10Log CFU ml⁻¹) were encapsulated using alginate (2% w/v), gelatinized starches (2% w/v) and lecithin (0–4% w/v) and stored in sealed containers at 4, 23 and 37°C (to simulate shelf storage conditions). Incorporation of lecithin improved the entrapment efficiency (p < 0.05) and the viability of encapsulated bacteria (p = 0.02). Encapsulated Lactobacillus, Bifidobacterium species and Lactococcus lactis in lecithin containing freeze-dried beads had good survival stability (above 6Log CFU ml⁻¹) at 23°C for 12 weeks. The bacteria in the beads showed 6Log survival by the end of 2 weeks at 37°C. Encapsulated L. casei in the alginate beads containing lecithin were also more stable in the yoghurt than the beads without lecithin. SEM analysis of the beads showed an irregular surface for the beads without lecithin.

• Probiotics
• lecithin
• encapsulation
• freeze drying
• stability