title: Structure and physicochemical properties of starches in lotus (Nelumbo nucifera Gaertn.) rhizome.
abstract: The type and content of starch are believed to be the most critical factors in determining the storage and processing quality of lotus rhizome species, and the intention of this study is to survey the structure and properties of starches isolated from rhizomes of two lotus cultivars using X-ray powder diffraction, solid-state nuclear magnetic resonance spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, scanning electron microscope, differential scanning calorimetry, and rapid viscosity analyzer (RVA). Starch in rhizome of cultivar Meirenhong exhibited C-type X-ray diffraction pattern, while starch in rhizome of cultivar Wawalian showed A-type pattern. (13)C cross-polarization magic-angle spinning nuclear magnetic resonance ((13)C CP-MAS NMR) also confirmed the polymorphs. The relative crystallinity of two starches was quantitatively estimated from two methods and compared. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) results indicated that the external regions of the starch granules had a great level of ordered structure. Starch granules in Meirenhong showed oval-shaped granules, while starch granules in Wawalian were elongated and oval in shape with relatively large size. Gelatinization temperatures of starch in Meirenhong and Wawalian were 330.5 and 342.4 K, respectively, and the gelatinization temperature range of Meirenhong was significantly wider than that of Wawalian. Starch in rhizome of cultivar Meirenhong showed lower pasting temperature, lower hot and cool viscosities, lower setback, and higher peak viscosity and breakdown than those of Wawalian in RVA pasting profiles at 6% starch concentration.
authors.affiliation: College of Physics Science and Technology, Yangzhou University Yangzhou, 225002, P. R. China.
authors.forename: Huaguang
authors.initials: H
authors.lastname: Yu
authors.affiliation: School of Horticulture and Plant Protection, Yangzhou University Yangzhou, 225009, P. R. China.
authors.forename: Libao
authors.initials: L
authors.lastname: Cheng
authors.affiliation: School of Horticulture and Plant Protection, Yangzhou University Yangzhou, 225009, P. R. China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Yin
authors.affiliation: College of Physics Science and Technology, Yangzhou University Yangzhou, 225002, P. R. China.
authors.forename: Shunjun
authors.initials: S
authors.lastname: Yan
authors.affiliation: College of Physics Science and Technology, Yangzhou University Yangzhou, 225002, P. R. China.
authors.forename: Kejun
authors.initials: K
authors.lastname: Liu
authors.affiliation: Testing Center, Yangzhou University Yangzhou, 225009, P. R. China.
authors.forename: Fengmin
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Testing Center, Yangzhou University Yangzhou, 225009, P. R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Xu
authors.affiliation: School of Horticulture and Plant Protection, Yangzhou University Yangzhou, 225009, P. R. China.
authors.forename: Liangjun
authors.initials: L
authors.lastname: Li
keywords: Crystalline structure; X-ray powder diffraction; lotus (Nelumbo nucifera Gaertn.) rhizome; solid-state nuclear magnetic resonance; starch