title: Ultrastructure of underutilized tuber starches and its relation to physicochemical properties.
abstract: Starches from five underutilized tubers (canna, potato, Chinese yam, water chestnut, and taro) were extracted to investigate quantitative structure-property relationships (QSPR) in each starch using a combination of X-ray diffraction (XRD) and small-angle X-ray scattering (SAXS). Structural parameters of the tuber starches were determined using the paracrystalline model. Swelling power (SP), water solubility index (WSI), amylose leaching (AML), and thermal properties were also measured. The XRD results indicated that starches from Chinese yam, water chestnut, and taro are C-type starches with relatively high crystallinity (29.23-35.02%). In contrast, canna and potato starches are B-type starches exhibiting lower crystallinity and higher amylose content. The paracrystalline model provided a better fit for the C-type starches than for the B-type starches because the former was highly compressible (indicated by a higher "β" value). B-type starches, on the other hand, tend to be more rigid along the lamellar repeat direction, requiring the layers to bend to accommodate internal stress. The QSPR analysis showed that three structural parameters, "Ø", "β", and "Δρu", correlate well with the SP and WSI, and thus can be used to predict certain physicochemical properties.
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Lan
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Yongfu
authors.initials: Y
authors.lastname: Li
authors.affiliation: AarhusKarlshamn, Shanghai 200137, China.
authors.forename: Shichao
authors.initials: S
authors.lastname: Xie
authors.affiliation: School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: zhengwuwang@sjtu.edu.cn.
authors.forename: Zhengwu
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000688:Amylose / Q000032:analysis; D021281:Quantitative Structure-Activity Relationship; D013213:Starch / Q000737:chemistry* / Q000648:ultrastructure*; D014961:X-Ray Diffraction / Q000379:methods*
chemical_list: D013213:Starch; D000688:Amylose
keywords: Paracrystalline model; Physicochemical properties; Quantitative structure–property relationship; Structural parameters; Ultrastructure; Underutilized tuber starches