Yang Hua-Sheng, Wu Wei-Gang, Tan Li-Xia, Wen Li-Zhen, Wang Xi-Lin, Jiang Ting, Wu Lu
Jiangxi University of Traditional Chinese Medicine, Nanchang 330004, China.
Zhongguo Zhong Yao Za Zhi. 2017 Feb;42(3):478-485. doi: 10.19540/j.cnki.cjcmm.20170103.013.
Hordei Fructus Germinatus has been always used by "stir-frying" as a traditional medicine and the endpoint judgment of "fragrant" and "yellow" has been the focus and difficulty in frying process research. In this study, a quantitative calibration model between index components and NIRS was established in order to rapidly detect the contents of reducing sugar, total amino acids, total flavonoids, A420 and moisture; besides, an endpoint judgment method of frying process was put forward based on the "component change rate". Near-infrared spectra of samples with different frying time were collected, and a quantitative analysis model based on near-infrared spectroscopy was established to optimize the parameters such as spectral pretreatment and modeling band. HCA and PLS-DA were used to study the relationship between component and "stir-frying", and the endpoint of frying process was determined. The established calibration model had a good performance that the correlation coefficients between the predicted results and the actual measured values were both more than 0.9, with predicted relative deviations less than 10%. Hordei Fructus Germinatus with different frying time was divided into 4 categories by HCA analysis. PLS-DA analysis showed that total reducing sugar had a significant contribution to distinguishing the Hordei Fructus Germinatus of different frying time. When the change rate of total reducing sugar was 80%, it could judge that the endpoint of frying had been obtained. Results showed that NIRS could not only quickly and accurately determine the contents of reducing sugar, total amino acid, total flavonoid, A420 and moisture in Hordei Fructus Germinatus samples of different frying time, but also judge the endpoint of frying in the process. This study provided a new method for the evaluation and endpoint judgment of "stir-frying" process in research of traditional Chinese medicine.
炒麦芽作为传统中药一直采用“炒制”的方法，“香气”和“黄色”的终点判断一直是炒制过程研究的重点和难点。本研究建立了指标成分与近红外光谱（NIRS）之间的定量校正模型，以快速检测还原糖、总氨基酸、总黄酮、A420和水分的含量；此外，基于“成分变化率”提出了炒制过程的终点判断方法。收集不同炒制时间样品的近红外光谱，建立基于近红外光谱的定量分析模型，对光谱预处理和建模波段等参数进行优化。采用聚类分析（HCA）和偏最小二乘判别分析（PLS-DA）研究成分与“炒制”之间的关系，确定炒制过程的终点。所建立的校正模型性能良好，预测结果与实际测量值之间的相关系数均大于0.9，预测相对偏差小于10%。通过HCA分析将不同炒制时间的炒麦芽分为4类。PLS-DA分析表明，总还原糖对区分不同炒制时间的炒麦芽有显著贡献。当总还原糖变化率为80%时，可判断已达到炒制终点。结果表明，近红外光谱不仅能快速准确地测定不同炒制时间炒麦芽样品中还原糖、总氨基酸、总黄酮、A420和水分的含量，还能判断炒制过程的终点。本研究为中药研究中“炒制”过程的评价和终点判断提供了一种新方法。
