Influence of co-encapsulation of Bifidobacterium animalis subsp. lactis Bb12 with inulin and ascorbic acid on its viability

Abstract

Eight types of capsules containing Bifidobacterium animalis subsp. lactis Bb12 with addition of inulin and/or ascorbic acid were prepared by emulsion method with milk protein matrix or by extrusion method with alginate matrix. The size of protein and alginate capsules containing only Bb12 was 204 ± 18 µm and 1.7 ± 0.1 mm, respectively. Addition of both inulin (1% w/w) and ascorbic acid (0.5% w/w) increased the size of alginate capsules. Both methods of encapsulation prevented efficiently the manifestation of Bb12 cell metabolic activity. All types of encapsulation provided higher resistance of Bb12 cells to the conditions of a model gastrointestinal tract (GIT) compared to free cells. The influence of co-encapsulation with inulin (1% w/w) and ascorbic acid (0.5% w/w) on viability in model GIT was not demonstrable in alginate capsules but it was significant in protein capsules. The most efficient was co-encapsulation in a protein matrix with 1% w/w inulin and 0.5% w/w ascorbic acid.

Keywords

• alginate
• emulsion encapsulation
• extrusion encapsulation
• gastrointestinal tract
• milk protein