Characteristics of synbiotic spray dried powder of litchi juice with Lactobacillus plantarum and different carrier materials

Spray drying of probiotic Lactobacillus plantarum in litchi juice with varied proportion of maltodextrin, fructooligosaccharide (FOS) and pectin was performed to determine the effect on cell viability. The spray dried powders were investigated for physical, physicochemical and toxicological properties and survivability of cells in simulated gastric and intestinal digestion. The results showed that coating material comprising of maltodextrin 10% (w/v) and 5% (w/v) FOS gave highest yield and survivability of the encapsulated bacteria. This composition of the coating material also showed good solubility, low water activity, satisfactory colour, uniform particle size with smooth surface. Powder coated with 10% (w/v) maltodextrin and 5% (w/v) pectin showed reduced powder properties and cell viability even though had the highest glass transition temperature. Maltodextrin at 10% (w/v) and FOS at 5% (w/v) levels in the coating material can be considered as the optimal carrier material composition for protection of the bacterial cells from damage by adverse environmental conditions of spray drying and for possessing desirable powder characteristics. This combination also provided protection to bacterial cells in gastric environment and also enhanced their growth in simulated digestive system.