Protection of Bifidobacteria Encapsulated in Polysaccharide-Protein Gel Beads against Gastric Juice and Bile

Abstract

Bifidobacterium cells were encapsulated in a mixed gel composed of alginate, pectin, and whey proteins. Two kinds of capsules were obtained: gel beads without membranes and gel beads with two membranes formed by the transacylation reaction. In vitro studies were carried out to determine the effects of simulated gastric pH and bile salts on the survival of free and encapsulated Bifidobacterium bifidum. The protective effects of gel beads without membranes and gel beads coated with two membranes formed by the transacylation reaction were evaluated. After 1 h in an acidic solution (pH 2.5), the free-cell counts decreased by 4.75 log units, compared with a <1-log decrease for entrapped cells. The free cells did not survive after 2 h of incubation at pH 2.5, while immobilized-cell counts decreased by about 2 log units. After incubation (1 or 3 h) in 2 and 4% bile salt solutions, the bifidobacterium mortality level for membrane-free gel beads (4 to 7 log units) was higher than that for free cells (2 to 3 log units). However, counts of bifidobacteria immobilized in membrane-coated gel beads decreased by <2 log units. Cell encapsulation in membrane-coated protein-polysaccharide gel beads could be used to increase the survival of healthy probiotic bacteria during their transit through the gastrointestinal tract.

Technology and potential applications of probiotic encapsulation in fermented milk products

“…Researchers used high concentrations of gelatine (24 % w/v) to encapsulate L. lactis by crosslinking with toluene−2, 4-diisocyanate for biomass production (Hyndman et al, 1993). Moreover, encapsulation of Bifidobacterium cells in a mixed gel composed of alginate, pectin and whey proteins has been investigated (Guerin et al, 2003). As a result, the encapsulated cells survived better that free cells in simulated gastric pH and bile solutions.…”

Development of New Products: Probiotics and Probiotic Foods

“…[164,165]. It has been shown that the optimum temperature for the development of probiotic strains is 35-40ºC and pH varies between 4,0 and 3,6 [6].…”

“…It has been shown that the optimum temperature for the development of probiotic strains is 35-40ºC and pH varies between 4,0 and 3,6 [6]. To protect the cells from the effects of the environmental factors agar, alginate, chitosan are used [165,166,167]. A probiotic banana product fermented with Lactobacillus acidophilus, included in alginate gel structures, is obtained.…”

Non-Conventional Tools to Preserve and Prolong the Quality of Minimally-Processed Fruits and Vegetables

“…It has been reported that the optimum probiotic growth temperature is between 35 and 40 °C, and the best pH is between 6.4 and 4.5, ceasing when a pH of 4.0-3.6 is reached [123]. This situation could be solved by using some supports, such as agar, polyacrylamide, calcium pectate gel, chemically-modified chitosan beads and alginates, to provide a physical barrier against unfavorable conditions [124][125][126].…”