Characteristics of transglycosylation reaction of cyclodextrin glucanotransferase in the heterogeneous enzyme reaction system using extrusion starch as a glucosyl donor

Characteristics of the intermolecular transglycosylation reactions of saccharides and glucosides by cyclodextrin glucanotransferase (CGTase) in the heterogeneous enzyme reaction system rising swollen extrusion starch as a glucosyl donor were analyzed. The transglycosylation yield and rate were significantly increased compared to the conventional reaction system using liquefied starch as the glucosyl donor. Various monosaccharides composed of the same configuration of 2-, 3-, and 4-OH with the D-glucopyranoside such as D-xylose, D-glucose, L-sorbose, and myo-inositol were found to be goad accepters for the transglycosylation reaction. Several glucosides such as stevioside and hesperidin were also identified as the suitable glucosyl accepters. The optimal transglycosylation reaction condition using stevioside as the glucosyl acceptor was also determined. The heterogeneous transglycosylation reaction system shows a few distinct advantages; minimized accumulation of oligosaccharides, easy removal of residual extrusion starch after reaction, and simplified purification of transglycosylated products, therefore, which will facilitate the industrial application of the various transglycosylation reactions. (C) 1998 Elsevier Science Inc.