Survival of spray-dried Lactobacillus kefir is affected by different protectants and storage conditions

Abstract

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.