Improvement of Lactobacillus acidophilus La-5 microencapsulation viability by spray-drying with rice bran protein and maltodextrin

摘要

Lactobacillus acidophilus La-5microencapsulation using rice bran protein (RBP) andmaltodextrin (MD) by spray-dryingwas studied. The effects of process variables—dryinginlet air temperature (x_1), inlet flow (x_2), and MD:RBP ratio (x_3)-onencapsulationefficiency (EE) and viability reduction (VR) during 45 storage days wereinvestigated using a 23 Central Composite Rotatable Design. EE (%) and viable cellsnumber increased when lower drying temperature, higher input flow, and high RBPproportion were applied. The optimum microencapsulation variables were x1 = 78°C,x_2 = 0.58 L/hr, and x_3 = 10:2.5 w w~(−1) (EE = 90.26%; VR = 2.64 log cycles). L. acidophilusshowed viability during storage, which remained higher than 8 log CFU/g after45 days at 4 ± 1°C. Microencapsulated L. acidophilus presented thermal stability up to240°C and its survival in a simulated gastric and intestinal fluids solution was greaterthan its free-form.The results suggested that MD and RBP provided the microencapsulatedmicroorganism with increased viability.