Enzymatic synthesis and structure determination of NEO-FOS

Because of their prebiotic properties, fructo-oligosaccharides (FOS) that b elong to inulin type are known to beneficially affect the host. Among eight commercial tested enzyme preparations, Cytolase PCL5 was found to possess the highest glycosyltransferase activity (7.4 U/ml and 0.17 U/mg proteins). Optimum conditions for FOS production from sucrose were found to be : pH 5 .5, temperature 55 degrees C and addition of 7 units of fructosyltransferas e activity per gram sucrose. In presence of glucose (competitive inhibitor) , the efficiency was 50% based the amount of sucrose consumed. Both HPLC an d C-13-NMR spectrometry analysis indicated that synthetised FOS belong to n eo-FOS type (neo-kestose, neo-nystose and neo-fructofuranosylnystose), a st ructure which is very close to inulin type (same linkage between fructosyl units).