Preparation of Highly Branched Starch by Glycogen Branching Enzyme from Neurospora crassa N2-44 and Its Characterization

Abstract

Waxy corn starch (WCS) was treated with the Neurospora crassa glycogen branching enzyme (BE), and the BE-treated WCS was characterized. The chain-length distribution pattern of the BEtreated WCS was similar to that of glycogen by HPAEC analysis, and the average chain-length changed from 21.2 to 15.2. The molecular mass of the BE-treated WCS was estimated at 2000 kDa using a calibration curve of pullulan by gel filtration chromatography. The apparent viscosity of a 3% paste of the BE-treated WCS was about 1/10 that of the same paste concentration containing the untreated WCS. The BE-treated WCS was soluble in water. The solution remained clear and no precipitate was observed after being stored at 4°C for 1 week.