Generation of short-chained granular corn starch by maltogenic α-amylase and transglucosidase treatment. (1st January 2021)

• Record Type: Journal Article
• Authors: Zhong, Yuyue; Keeratiburana, Thewika; Kain Kirkensgaard, Jacob Judas; Khakimov, Bekzod; Blennow, Andreas; Hansen, Aleksander Riise
• Is Part Of: Carbohydrate polymers. Volume 251(2021)
• Publication Date: 2021-01-01
• Subjects: Starch -- Maltogenic α-amylase -- Transglucosidase -- Solid-state modification; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2020.117056
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Maltogenic α-amylase (MA) and Transglucosidase (TGA) successfully modified maize starch granules. MA pre-treatment is a requirement for TGA to efficiently act on granular maize starch. MA and TGA treatment increased the amounts of amylopectin chains with DP < 10. Moderate MA → TGA treatment generated porous, less crystalline granules with low paste viscosity. Long MA → TGA treatment regained the granular crystallinity. Abstract: We describe a method for permitting efficient modification by transglucosidase (TGA), from glycoside hydrolase family 31 (GH31), sequentially after the pre-treatment by maltogenic α-amylases (MA) from GH13. TGA treatment without MA pre-treatment had negligible effects on native starch, while TGA treatment with MA pre-treatment resulted in porous granules and increased permeability to enzymes. MA→TGA treatments lead to decreased molecular size of amylopectin molecules, increased α-1, 6 branching, and increased amounts of amylopectin chains with the degree of polymerization (DP)<10 and decreased amounts of DP 10-28 after debranching. Wide-angle X-ray scattering (WAXS) data showed a general decrease in crystallinity except for a long term (20 h) TGA post-treatment which increased the relative crystallinity back to normal. MA→TGA treatment significantly lowered the starch retrogradation of starch and retarded the increase of storage- and loss moduli during storage. This work demonstrates the potential of sequential addition of starch active enzymes to obtain granular starch with improved functionality.