Microencapsulation of Limosilactobacillus reuteri DPC16 by spray drying using different encapsulation wall materials

Most probiotics are delivered in liquid media which tends to limit their shelf life thus, they are not convenient for the modern lifestyles. In this study, Limosilactobacillus reuteri DPC16 was encapsulated in 10% reconstituted skim milk (RSM), 10% gum Arabic, 10% maltodextrin, and a mixed wall material (2.5% whey protein isolate/2.5% gum Arabic/2.5% inulin/2.5% sucrose), (w/w). The mixture was then spray-dried at 160 degrees C/80 degrees C and/or 180 degrees C/100 degrees C inlet/outlet temperatures. The spray-dried DPC16 microcapsules were characterized for viable cells of the probiotic, a(w), and morphology. Results showed that at the inlet/outlet temperatures of 160 degrees C/80 degrees C, RSM as an encapsulation wall material had the highest cell counts (98.06% +/- 0.86%) with 0.196 +/- 0.010 a(w). Most of the powder particles (RSM) were spherical with dented surfaces. At 180 degrees C/100 degrees C, about 84% DPC16 cells survived in RSM capsules. Thus, RSM showed good potential as an encapsulating wall material to maintain high DPC16 cell viability during spray drying. Novelty impact statement The encapsulation of Limosilactobacillus reuteri DPC16 using reconstituted skim milk (RSM) by spray drying at elevated inlet/outlet temperatures had lower encapsulation efficiency (EE), water activity, and smaller particle size of the microcapsules compared to RSM microcapsules spray-dried at low temperatures. Mixed wall material comprising gum Arabic, whey protein isolate, inulin, and sucrose produced microcapsules with relatively high EE, low water activity, and some microcapsules with smoother surfaces which could improve powder solubility.