Lactic acid bacteria microencapsulation in sodium alginate and other gelling hydrocolloids mixtures

Lactic acid bacteria were microencapsulated with alginate and other gelling hydrocolloids (gellan gum and kappa-carrageenan/locust bean gum). Sodium alginate microcapsules with gellan gum resulted in a harder and more resilient less viscous texture, with low particle size diameter, with enhanced viability of the microencapsulated bacteria. In contrast, sodium alginate microcapsules with kappa-carrageenan/locust bean gum resulted in softer and less resilient (more viscous) texture. Although the particle size diameter was higher than alginate + gellan gum treatment, the microcapsules were smaller and with better viability than sodium alginate alone. Correlation analysis showed that microcapsules with lower surface area diameter were harder, more resilient and less viscous, enhancing cells viability and reducing acidification rates. Higher surface area affected negatively the growth and fermentative capability of encapsulated lactic acid bacteria. The incorporation of gellan or kappa-carrageenan/locust bean gum into alginate beads resulted in a lower surface area that, on one hand, enhanced cell viability and, on the other hand, in moderate milk acidification in fermentation tests. The use of alginate with gellan gum represents a good alternative to protect lactic acid bacteria in order to be inoculated in functional processed foods.