Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8585, Japan; Department of Orthopedic Surgery, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo 160-0023, Japan; The Center for Advanced Medical Engineering and Informatics, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0854, Japan; Department of Immunology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, 465 Kajii-cho, Kyoto 602-8566, Japan.
Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8585, Japan.
Food Chem. 2021 Aug 30;354:129434. doi: 10.1016/j.foodchem.2021.129434. Epub 2021 Mar 6.
Analytical algorithms based on Raman spectroscopy are proposed for the determination of amylopectin and amylose concentrations in polished white rice, and applied to characterize and compare linear and branched polysaccharide structures in nine different types of Japanese rice. A selected algorithm used symmetric bending vibrations of the COC glycosidic linkage from a relatively narrow spectral zone between 830 and 895 cm. It specifically compared the intensity of Raman signals from two types of bending common to both starch components (C1-O-C5 and C1-O-C4 at 868 and 855 cm, respectively) and that at the branch point peculiar to amylopectin (C1-O-C6 at 844 cm). Raman data were confronted with data collected by conventional amylose-iodine colorimetry method. Consistency was found between Raman and colorimetric methods over the entire series of tested rice cultivars, thus validating the newly proposed spectroscopic algorithm. The amylose content of the tested rice species broadly varied between 1.2 and 20.4%. The proposed Raman algorithm allows fast and nondestructive determination of amylose content in rice with minimal sample preparation. These characteristics might be key in the development of portable Raman devices capable to promptly screen polysaccharides in different rice cultivars with respect to their interannual and plantation-related fluctuations.
基于拉曼光谱的分析算法被提出用于测定抛光白米中支链淀粉和直链淀粉的浓度，并应用于表征和比较 9 种不同类型的日本大米中直链和支链多糖结构。所选择的算法使用了 COC 糖苷键的对称弯曲振动，来自相对较窄的光谱区域 830 至 895 cm-1 之间。它特别比较了两种淀粉成分共有的两种弯曲的拉曼信号强度（分别为 868 和 855 cm-1 处的 C1-O-C5 和 C1-O-C4 以及支链淀粉特有的支叉点处的 C1-O-C6 （844 cm-1）。拉曼数据与常规直链淀粉碘比色法收集的数据进行了对比。在整个测试的水稻品种系列中，拉曼和比色法之间存在一致性，从而验证了新提出的光谱算法。测试的水稻品种的直链淀粉含量在 1.2 到 20.4%之间广泛变化。所提出的拉曼算法允许快速、无损地测定大米中的直链淀粉含量，只需最小的样品制备。这些特性可能是开发能够快速筛选不同水稻品种中多糖的便携式拉曼设备的关键，这些设备可以根据其年度间和种植园相关的波动来进行。
