基于LF-NMR/MRI的丹参加工过程水分变化与色差相关性研究

LF-NMR and color technology analysis of moisture changes during the processing of Salvia miltiorrhiza

采用低场核磁共振成像技术研究丹参浸润和干燥过程中水分状态,分析加工前后水分迁移规律,为根茎类中药水分控制提供科学手段;通过色差技术测定丹参不同状态下色差值,从色泽和水分角度阐述丹参加工炮制机理。结果显示丹参内部水分主要分为两种状态:自由水和结合水;药材自由水含量约为2.02%,浸润6 h后约为88.76%;鲜根自由水含量约97.74%,50℃干燥24 h内层结合水含量约为6.82%,基本达干燥临界点;低场核磁信号量与水质量呈现较好相关性,根据弛豫峰面积直观得出加工过程药材内部水分分布;弛豫峰面积值和色差值显示含水量和外观性状两者间有相关性。低场核磁共振技术为研究丹参加工过程中水分变化提供了直观的参考依据,为根茎类药材在加工时水分临界点控制提供一种科学工具,也为中药材炮制工艺研究提供新思路。

LF-NMR was used to study the internal water state of Salvia miltiorrhiza in the process of infiltration or drying,and the migration rule before and after processing was analyzed.This study provides a scientific method for water control of rhizoma.The color value of S.miltiorrhiza was determined by color difference technique.The chemical mechanism of S.miltiorrhiza processing was described from the perspective of color and moisture.The results show that the internal water of S.miltiorrhiza can be divided into two states,free water and bound water.The free water content of S.miltiorrhiza in dry condition was 2.02%,and about 88.76%after 6 h infiltration.Under the condition of fresh root of S.miltiorrhiza,the free water content was about 97.74%,the drying point reached 24 h at 50℃,and the inner bound water content was about 6.82%.The signal has a good correlation with the water quality,and the relaxation peak area can be used to obtain the water distribution during the processing of traditional Chinese medicine.The results of relaxation peak area and color difference indicated that there was a correlation between water content and appearance.