Different structural properties of high-amylose maize starch fractions varying in granule size.
Large-, medium-, and small-sized granules were separated from normal and high-amylose maize starches using a glycerol centrifugation method. The different-sized fractions of normal maize starch showed similar molecular weight distribution, crystal structure, long- and short-range ordered structure, and lamellar structure of starch, but the different-sized fractions of high-amylose maize starch showed markedly different structural properties. The amylose content, iodine blue value, amylopectin long branch-chain, and IR ratio of 1045/1022 cm(-1) significantly increased with decrease of granule size, but the amylopectin short branch-chain and branching degree, relative crystallinity, IR ratio of 1022/995 cm(-1), and peak intensity of lamellar structure markedly decreased with decrease of granule size for high-amylose maize starch. The large-sized granules of high-amylose maize starch were A-type crystallinity, native and medium-sized granules of high-amylose maize starch were CA-type crystallinity, and small-sized granules of high-amylose maize starch were C-type crystallinity, indicating that C-type starch might contain A-type starch granules.
Key Laboratories of Crop Genetics and Physiology of the Jiangsu Province and Plant Functional Genomics of the Ministry of Education, ‡Co-Innovation Center for Modern Production Technology of Grain Crops, and #Testing Center, Yangzhou University , Yangzhou 225009, China.
Canhui
C
Cai
Lingshang
L
Lin
Jianmin
J
Man
Lingxiao
L
Zhao
Zhifeng
Z
Wang
Cunxu
C
Wei
D000688:Amylose / Q000737:chemistry* / Q000302:isolation & purification; D015394:Molecular Structure; D008970:Molecular Weight; D003313:Zea mays / Q000737:chemistry*
D000688:Amylose
crystal structure; granule size; high-amylose starch; maize; molecular weight distribution; structural property