Effect of inlet air temperature and gum Arabic concentration on encapsulation of probiotics by spray drying

Encapsulation of probiotics using food grade polymers as wall material can be a good alternative for the development of any probiotic food. The current study details about the effect of processing conditions on physicochemical and flow properties of microencapsulated probiotic powder by spray drying. Maltodextrin and gum Arabic (GA) are used as wall material where 20% MD is kept constant. Varied concentration of GA (0, 2.5, 5, 7.5 and 10%) with respect to total solid content and inlet air temperature (130, 140 and 150 degrees C) was chosen as independent variables to produce the spray dried probiotic powder. The moisture content, water activity, and encapsulation efficiency of probiotic powder was in the range of 4.59-9.05% (w.b.), 0.52 to 0.33, and 65-89.15%, respectively. The loose bulk density, tapped density, true density, porosity and color L* ranged from 0.47 to 0.53 g/cm(3), 0.56-0.68 g/cm(3), 0.6-1.06 g/cm3 0.17-0.55, and 91.35-95.68, respectively. The handling properties i.e., flowability was "possible" and "fair" according to Hausner ratio and Carr's index values.