Structural Properties of Hydrolyzed High-Amylose Rice Starch by α-Amylase from Bacillus licheniformis

• Published in: Journal of agricultural and food chemistry Vol. 59; no. 23; pp. 12667 - 12673
• Main Authors: Qin, Fengling, Man, Jianmin, Xu, Bin, Hu, Maozhi, Gu, Minghong, Liu, Qiaoquan, Wei, Cunxu
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14.12.2011
• Subjects: alpha-amylase; alpha-Amylases - metabolism; amylose; Amylose - analysis; Bacillus - enzymology; Bacillus licheniformis; Biological and medical sciences; Cereal and baking product industries; crystal structure; differential scanning calorimetry; enthalpy; Food Chemistry/Biochemistry; Food industries; Fundamental and applied biological sciences. Psychology; gelatinization; gelatinization temperature; Glucan 1,4-alpha-Glucosidase - metabolism; human health; Hydrolysis; Oryza - chemistry; Pancreatic alpha-Amylases - metabolism; Plants, Genetically Modified - chemistry; resistant starch; rice; rice starch; Seeds - chemistry; Starch - chemistry; Starch - metabolism; Starch and starchy product industries; starch granules; X-radiation; high-amylose starch granule; structural property; α-amylase; enzyme hydrolysis; Rice; Enzyme; Bacillus licheniformis; Bacillaceae; Properties; Glycosylases; Starch granule; Hydrolysis; Amylose; Bacillales; Glycosidases; Bacteria; Cereal; Hydrolases; α-Amylase; Amylolytic enzyme; Polysaccharide; Rice starch
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf203167f

High-amylose cereal starch has a great benefit on human health through its resistant starch (RS) content. Enzyme hydrolysis of native starch is very helpful in understanding the structure of starch granules and utilizing them. In this paper, native starch granules were isolated from a transgenic rice line (TRS) enriched with amylose and RS and hydrolyzed by α-amylase. Structural properties of hydrolyzed TRS starches were studied by X-ray powder diffraction, Fourier transform infrared, and differential scanning calorimetry. The A-type polymorph of TRS C-type starch was hydrolyzed faster than the B-type polymorph, but the crystallinity did not significantly change during enzyme hydrolysis. The degree of order in the external region of starch granule increased with increasing enzyme hydrolysis time. The amylose content decreased at first and then went back up during enzyme hydrolysis. The hydrolyzed starches exhibited increased onset and peak gelatinization temperatures and decreased gelatinization enthalpy on hydrolysis. These results suggested that the B-type polymorph and high amylose that formed the double helices and amylose–lipid complex increased the resistance to BAA hydrolysis. Furthermore, the spectrum results of RS from TRS native starch digested by pancreatic α-amylase and amyloglucosidase also supported the above conclusion.