A new way of producing isomalto-oligosaccharide syrup by using the transglycosylation reaction of neopullulanase.

A new way of producing isomalto-oligosaccharide syrup from starch was developed. Isomalto-oligosaccharides contain one or more alpha-(1-->6)-glucosidic linkages with or without alpha-(1-->4)-glucosidic linkages. The isomalto-oligosaccharide syrups are receiving increased attention as food additives because it is thought that they help prevent dental caries and improve human intestinal microflora, acting as a growth factor for bifidobacteria. The new system for production of isomalto-oligosaccharide syrup is based on the strong alpha-(1-->6)-transglycosylation reaction of neopullulanase. Bacillus subtilis saccharifying alpha-amylase was simultaneously used with neopullulanase to improve the yield of isomalto-oligosaccharides. The yield of isomalto-oligosaccharides was increased to more than 60%, compared with a yield of 45.0% obtained by the conventional system. To reduce the costs, the use of immobilized neopullulanase was investigated. Almost the same yield of isomalto-oligosaccharides was obtained by using immobilized neopullulanase.