Abstract: Optimal conditions of spray drying of a fructooligosaccharide-rich mixture prepared by enzymatic conversion of sucrose were investigated. It was found that efficient drying of the mixture containing about 40 % of monosaccharides and sucrose required addition of a compound with a high glass transition temperature. The addition of maltodextrin helped to achieve satisfactory solids yield and moisture. Optimized process parameters were the feed flow rate and solids concentration, drying air flow rate and inlet temperature