Evaluation of thermal tolerance of co-encapsulated beads incorporated with probiotic culture and L-ascorbic acid

The proposed work was focused on the thermo tolerance of co-encapsulated beads formed with lactic acid bacteria and ascorbic acid. The beads were prepared by emulsion and extrusion method of encapsulation wherein coating material sodium alginate (4 %) and maize starch (2 %) were used. Microcapsules thus prepared by these two methods were freeze dried at -72˚C under vacuum. Thermo tolerance of the co-encapsulated beads were analyzed to check their stability under different temperatures viz. 45, 55, 65 and 75°C for 20 minutes using distilled water as suspending medium. In case of beads made from extrusion method, treatment and periodic mean value showed a significant difference from initial mean of 10.01 log to 8.61 log. For ascorbic acid a significant reduction was observed in the treatment mean values. In periodic mean value also, a significant difference was observed from initial mean of 14.39 mg to 10.24 mg. For each of the temperatures applied, the lowest reduction was observed at 45˚C (1.63 mg) and highest reduction was observed at 75˚C (5.97 mg). In case of beads made from emulsion method, a significant reduction was observed in the treatment as well as periodic mean values. For each of the temperatures applied, a significantly lowest and highest reduction was observed at 45˚C (0.13 log) and 75˚C (1.83 log), respectively. Similarly. a significant reduction was observed in the treatment mean values and periodic mean values for ascorbic acid and significantly lowest reduction was noted at 45˚C (1.08 mg) and highest at 75˚C (6.8 mg).