Branched alpha-glucan, alpha-glucosyltransferase which forms the glucan, their preparation and uses

摘要

The present invention has objects to provide a glucan useful as water-soluble dietary fiber, its preparation and uses. The present invention solves the above objects by providing a branched α-glucan, which is constructed by glucose molecules and characterized by methylation analysis as follows:
(1) Ratio of 2,3,6-trimethyl-1,4,5-triacetyl-glucitol to 2,3,4-trimethyl-1,5,6-triacetyl-glucitol is in the range of 1:0.6 to 1:4;(2) Total content of 2,3,6-trimethyl-1,4,5-triacetyl-glucitol and 2,3,4-trimethyl-1,5,6-triacetyl-glucitolis 60% or higher in the partially methylated glucitol acetates;(3) Content of 2,4,6-trimethyl-1,3,5-triacetyl-glucitol is 0.5% or higher but less than 10% in the partially methylated glucitol acetates; and(4) Content of 2,4-dimethyl-1,3,5,6-tetraacetyl-glucitol is 0.5% or higher in the partially methylated glucitol acetates; a novel α-glucosyltransferase which forms the branched α-glucan, processes for producing them, and their uses.

主权项

1. A process for producing a saccharide composition comprising branched α-glucan, comprising the steps of:
allowing an α-glucosyltransferase and cyclomaltodextrin glucanotransferase to act on maltose and/or α-1,4 glucan having a glucose polymerization degree of 3 or higher; and collecting the formed saccharide composition comprising branched α-glucan; said saccharide composition is characterized in that the content of water-soluble dietary fiber of the saccharide composition, obtained by applying a high performance liquid chromatography method (Enzyme-HPLC method), is 40% (w/w) or higher.