Key Laboratory of TCM Quality Control Technology, Shandong Analysis and Test Center, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China.
College of Food Science and Engineering, Shandong Agricultural University, Tai'an 270018, China.
Molecules. 2019 Jan 10;24(2):236. doi: 10.3390/molecules24020236.
Blume () is a prominent traditional herb and its dry tuber is officially listed in the Chinese Pharmacopoeia. To ensure the quality of dried , the establishment of a nondestructive and convenient method to monitor the drying process is necessary. In this study, a nondestructive low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) method was introduced to monitor the drying process of . Three water states (bound, immobilized, and free) in samples were investigated through multiexponential fitting and inversion of the NMR data. The variation and distribution of the three water states during drying were monitored by LF-NMR, and the spatial distribution of water and internal structural changes were analyzed by MRI. Linear analysis of the moisture content, (lightness), (yellowness), and NMR parameters showed good correlations among them. Furthermore, partial least squares regression (PLSR) model analysis, which takes into account all NMR parameters, also showed good correlations among these parameters. All results showed that LF-NMR was feasible and convenient for monitoring moisture content. Therefore, LF-NMR and MRI could be used to monitor the moisture content nondestructively in the drying process of Chinese traditional herbs.
白首乌是一种著名的传统草药，其干燥块根被中国药典正式收录。为确保干燥品的质量，有必要建立一种无损且方便的方法来监测干燥过程。本研究采用无损低场核磁共振（LF-NMR）和磁共振成像（MRI）方法监测白首乌的干燥过程。通过对 NMR 数据的多指数拟合和反演，研究了 样品中的三种水状态（结合水、束缚水和自由水）。通过 LF-NMR 监测干燥过程中三种水状态的变化和分布，并通过 MRI 分析水的空间分布和内部结构变化。水分含量、L值、a值和 NMR 参数的线性分析表明，它们之间存在良好的相关性。此外，考虑所有 NMR 参数的偏最小二乘回归（PLSR）模型分析也表明这些参数之间存在良好的相关性。所有结果表明 LF-NMR 可用于监测水分含量，因此 LF-NMR 和 MRI 可用于无损监测中药干燥过程中的水分含量。
