Development of a novel starch-based dietary fiber using glucanotransferase. Issue 13 (21st May 2021)

• Record Type: Journal Article
• Authors: Yang, Yuqi; Zhao, Xinqi; Zhang, Tao; Hamaker, Bruce R.; Miao, Ming
• Is Part Of: Food & function. Volume 12:Issue 13(2021)
• Page Start: 5745
• Page End: 5754
• Publication Date: 2021-05-21
• Subjects: Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; Nutrition -- Periodicals; 664.07
• DOI: 10.1039/d1fo00287b
• Languages: English
• ISSNs: 2042-6496

Abstract

Abstract : The recombinant microbial GTase had a stronger affinity for high-amylose starch to produce the reuteran-like high-branched glucan, which linked by single linear α-1, 6 linkages and α-1, 4/6 branching points as a promising prebiotic dietary fiber. Abstract : In this study, a glucanotransferase from prokaryotic Azotobacter chroococcum NCIMB 8003 was recombinantly expressed and its biochemical characteristics and bioconversion ability for starch were investigated. The purified enzyme has the optimum activity at 55 °C and pH 6.5–7.0, as well as a melting temperature of 62 °C. The double-charged ion Ca 2+ stimulated the activity of the enzyme by approximately 2.4 times. The kinetic parameters and specificity analysis revealed that this glucanotransferase had a higher affinity for high-amylose starch. During the transglycosylation reaction, the starch molecule was converted into a relatively small polymer with a narrow size distribution. For the enzyme modification of high-amylose starch for 72 h, the amount of α-1, 6 linkages increased from 1.9% to 22.7% and the content of resistant starch (RS) increased from 3.18% to 17.83%. In addition, the fine structure displayed the reuteran-like highly branched glucan linked by single linear α-1, 6 linkages and α-1, 4/6 branching points. These results revealed that a promising prebiotic dietary fiber was synthesized from starch with glucanotransferase modification.