Survival of two Lactobacillus kefir strains after spray drying in reconstituted skim milk with or without the addition of 12.5 g monosodium glutamate/l, 20 g sucrose/l, or 20 g fructo-oligosaccharides (FOS)/l and during subsequent storage under different conditions of temperature (20 and 30°C) and relative humidity (0, 11 and 23%) was evaluated. After being dried, Lactobacillus kefir 8321 and L. kefir 8348 had a decrease in viability of 0.29 and 0.70 log c.f.u./ml respectively, while the addition of different protectants improved the survival of both strains significantly. During storage, bacterial survival was significantly higher under lower conditions of relative humidity (0-11%), and monosodium glutamate and FOS proved to be the best protectants.Centro de Investigación y Desarrollo en Criotecnología de Alimentos