Synthesis of Thermo- and Acid-stable Novel Oligosaccharides by Using Dextransucrase with High Concentration of Sucrose

Abstract

A method is presented for synthesizing thermo-, acid-stable glucooligosaccharides (TASOG) from sucrose (2.5-4 M) using a dextransucrase prepared from Leuconostoc mesenteroides B-512FMCM. The degree of polymerization (DP) of oligosaccharides synthesized was from 2 to 11. TASOG resisted hydrolysis of its glycosidic linkages at 140°C and pH 6.0 for 1 h. It was stable at pHs ranging from 2 to 4 at 120°C. A method for synthesizing fructo-oligosaccharides (TASOF) with high concentrations of sucrose (1-3 M) by using levansucrase prepared from L. mesenteroides B-1355C was also developed. The DP of oligosaccharides synthesized according to the present method ranged from 2 to over 15. The TASOF was also stable at pHs ranging from 2 to 4 under 120°C. The percentage of TASOF in the reaction digest was 95.7% (excluding monosaccharides; 4.3% was levan). Both oligosaccharides effectively inhibited the formation of insoluble glucan, and the growth and acid production of Streptococcus sobrinus. TASOG and TASOF potentially can be used as sweeteners for food and beverages where thermo- and acid-stable properties are required and as potential inhibitors of dental caries.