Microencapsulation of Lactobacillus acidophilus LA-5 using spray drying

Probiotics are living microorganisms with several benefits for human health when administered in adequate amounts. Spray drying is a well-known microencapsulation method which has been investigated as a means of stabilizing probiotic bacteria in a number of food matrices, composed of proteins, polysaccharides, sugars, and their combinations. The aim of this study was using spray drying technique to encapsulate Lactobacillus acidophilus La-5. The effect of encapsulating agent (maltodextrin and inulin), their concentration (20 to 40 % w/v) and inlet temperature (120 to 140 °C) on the viability of Lactobacilllus acidophilus La-5 was studied. In this work the flow rate of 10 mL/min was maintained constant for all experiments. Before, the lyophilized probiotic culture was reactivated in skimmed milk, using 0.05 % of Lactobacillus acidophilus La-5 and 6 % of fructooligosaccharides for 150 minutes at 37 °C. We observed that when maltodextrin or inulin at 20 % (w/v) were used at temperature of 120 °C the viability was reduced only two log CFU. In the case of inulin and 140 °C, increasing the covering agent from 20 % to 40 % (w/v) resulted to increase of viability of the microorganism. At 140 °C, the viability reduced 65.5 % and 37.4 % when 20 % and 40 % of inulin were used, respectively. The results of this study confirm the appropriateness of the spray drying to encapsulate probiotics using prebiotic compound such as inulin. Encapsulated microorganisms can be used to produce different food formulations.