Microencapsulation of Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12 and Propionibacterium jensenii 702 by spray drying in goat's milk

• Spray drying resulted in a significant reduction in the viability of all probiotics.
• The viability of all probiotics decreased dramatically when stored at 30 °C.
• Probiotics were able to retain satisfactory viability during storage at 4 °C.
• Goat's milk seemed to be a suitable carrier material in probiotic microencapsulation.

A mixture of probiotic Lactobacillus acidophilus LA-5, Bifidobacterium animalis subsp. lactis BB-12 and novel potential probiotic Propionibacterium jensenii 702 was resuspended in reconstituted (20% w/v) goat's milk, spray dried in a mini spray dryer (inlet temperature = 195 °C and outlet temperature = 85 °C) and the spray dried powder was stored in air tight glass jars at 4 °C and 30 °C for 24 weeks. Powder quality and probiotic viability after spray drying and subsequent storage were measured. Spray drying probiotics in reconstituted goat's milk resulted in a significant reduction in the viability of all three probiotics. However, all three probiotics were able to maintain satisfactory viability levels (106–108 cfu/g) after spray drying. While storage temperature did not appear to have a significant effect on moisture content, the viability of all three strains declined dramatically when stored at 30 °C but lactobacilli and propionibacteria remained virtually unaffected under storage at 4 °C, satisfying recommendations regarding the level of viable cells in probiotic foods.