目的 建立熟地黄Rehmanniae Radix Praeparata九蒸九晒过程的客观终点判据，量化“形-色-味”变化，并阐明成分转化与美拉德反应的相关性。方法 采用清蒸与酒蒸2种工艺制备熟地黄1～9次蒸晒样品，联合电子舌、电子鼻、电子眼、质谱成像和红外光谱法，获取滋味、气味及色度参数，解析成分的空间分布及动态变化以及特征官能团的迁移规律。结果 电子感官数据与人工感官评价结果一致，可准确区分不同蒸晒次数的地黄样品。滋味转变以“三蒸三晒”为关键拐点，色度值随蒸晒次数增加逐渐降低，符合“光黑如漆，甜如饴”的传统质量标准。气味差异标志物为丙烷类化合物。质谱成像结果显示，随炮制程度加深，环烯醚萜类、氨基酸类及非还原糖含量呈递减趋势，还原糖与5-羟甲基糠醛含量递增，苯乙醇类呈先升后降再升趋势。红外光谱显示糖苷羟基及共轭羰基特征峰变化符合美拉德反应特征。酒蒸因有机酸催化作用，各品质拐点较清蒸组提前1个蒸次完成，但终点质量无显著差异。结论 多维度评价体系客观呈现了熟地黄九蒸九晒过程的“形-色-味”演变规律；研究结果为熟地黄炮制终点判定提供了量化依据，并为蒸晒类中药的质量控制提供了技术范式。

Objective To establish an objective endpoint criterion for the nine cycles of steaming and sun-drying in the processing of Shudihuɑng (Rehmanniae Radix Praeparata, RRP), to quantitatively characterize the dynamic changes in “morphology, color, and taste”, and to elucidate the correlation between chemical component transformations and the Maillard reaction. Methods Samples subjected to one through nine cycles of conventional steaming and wine-assisted steaming were prepared. An integrated analytical approach combining electronic tongue, electronic nose, electronic eye, mass spectrometry imaging, and infrared spectroscopy was employed to obtain quantitative parameters related to taste, odor, and chromaticity. These data were used to analyze the spatial distribution and dynamic variation of chemical constituents, as well as the migration patterns of characteristic functional groups. Results The electronic sensory data exhibited strong concordance with the results of manual sensory evaluation and demonstrated high discriminative capability among RRP samples subjected to varying cycles of re-hydration and re-drying. A pronounced shift in taste profile was observed at the third cycle of re-hydration and re-drying, identified as the critical inflection point for sensory deterioration. Concurrently, the color value decreased progressively with increasing reprocessing cycles—a trend consistent with the traditional quality benchmark “black as lacquer, sweet as honey”, wherein darker coloration correlates with superior quality. Volatile propane-type compounds were identified as key odor discriminants across treatment groups. Mass spectrometry imaging revealed that with increasing processing intensity, the levels of iridoid compounds, amino acids, and non-reducing sugars progressively declined, whereas those of reducing sugars and 5-hydroxymethylfurfural increased steadily. In contrast, phenethyl alcohol exhibited a triphasic trend—initially increasing, subsequently decreasing, and finally rising again. Fourier-transform infrared (FTIR) spectroscopy further demonstrated characteristic shifts in absorption peaks corresponding to sugar-derived hydroxyl groups and conjugated carbonyl moieties, consistent with hallmark spectral features of the Maillard reaction. Notably, organic acids present in the wine-steaming medium exerted a catalytic effect, advancing the onset of quality inflection points by one steaming cycle relative to the clear-steaming control group; However, no statistically significant difference in final product quality was observed between the two processing modalities. Conclusion The proposed multi-dimensional evaluation system objectively captures the evolutionary patterns of “morphology, color, and taste” throughout the nine-cycle steaming and sun-drying process of processed RRP. These findings provide a quantitative foundation for determining the optimal processing endpoint and offer a technical framework for quality control in the production of steamed and sun-dried traditional Chinese medicines.

R283.6

国家自然科学基金重点项目（82574586）；山西省基础研究计划（202503021211210）；中医药管理局科研课题项目（2023ZYYA2012）；山西省中医药科技创新工程项目（CZ2023041_019）；中医药产业发展现代化支撑项目（2025zyycy01）；山西省留学人员科技活动择优资助项目（20230034）；山西省筹资金资助归国留学人员科研项目（2023-156）；太原市揭榜挂帅项目（2023048）；山西中医药大学研究生科研实践创新项目（X2025SJ034）；山西中医药大学博士科研启动基金项目（2023BK38）；山西中医药大学科技创新能力培育计划（2024PY-JL-7-02）