Microentrapment of Lactobacilli in Calcium Alginate Gels

A procedure was developed to entrap culture bacteria using a two-phase (water/oil) system. It consisted of 3% sodium alginate mixed with microbial cells and suspended in an oil bath containing 0.2% Tween 80. While stirring at 200 rpm, calcium chloride (O.OSM) solution was added to break the water/oil emulsion and form calcium alginate gel. The calcium alginate beads containing microbial cells had mean diameters of 25–35 μm (range S-100 μm). The entrapped microbial cells were released completely from the drop shaped beads by gentle shaking in 0.lM phosphate solution (pH 7.5) for 10 min. About 40% more lactobacilli survived freezing of ice milk when they were entrapped in calcium alginate than when they were not entrapped.