School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; Key Laboratory of Modern Agricultural Equipment and Technology., Zhenjiang 212013, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2018 Jan 5;188:436-442. doi: 10.1016/j.saa.2017.07.023. Epub 2017 Jul 19.
Hyperspectral images (431-962nm) and partial least squares (PLS) were used to detect the distribution of triterpene acids within loquat (Eriobotrya japonica) leaves. 72 fresh loquat leaves in the young group, mature group and old group were collected for hyperspectral imaging; and triterpene acids content of the loquat leaves was analyzed using high performance liquid chromatography (HPLC). Then the spectral data of loquat leaf hyperspectral images and the triterpene acids content were employed to build calibration models. After spectra pre-processing and wavelength selection, an optimum calibration model (Rp=0.8473, RMSEP=2.61mg/g) for predicting triterpene acids was obtained by synergy interval partial least squares (siPLS). Finally, spectral data of each pixel in the loquat leaf hyperspectral image were extracted and substituted into the optimum calibration model to predict triterpene acids content of each pixel. Therefore, the distribution map of triterpene acids content was obtained. As shown in the distribution map, triterpene acids are accumulated mainly in the leaf mesophyll regions near the main veins, and triterpene acids concentration of young group is less than that of mature and old groups. This study showed that hyperspectral imaging is suitable to determine the distribution of active constituent content in medical herbs in a rapid and non-invasive manner.
利用高光谱图像（431-962nm）和偏最小二乘法（PLS）检测枇杷叶中三萜酸的分布。采集了幼龄组、成熟组和老龄组共 72 片新鲜枇杷叶进行高光谱成像，采用高效液相色谱法（HPLC）分析枇杷叶中三萜酸的含量。然后，利用枇杷叶高光谱图像的光谱数据和三萜酸含量建立校准模型。经过光谱预处理和波长选择，协同间隔偏最小二乘法（siPLS）得到了一个预测三萜酸的最佳校准模型（Rp=0.8473，RMSEP=2.61mg/g）。最后，从枇杷叶高光谱图像中提取每个像素的光谱数据，并代入最佳校准模型预测每个像素的三萜酸含量，从而得到三萜酸含量的分布图。从分布图可以看出，三萜酸主要在靠近主叶脉的叶片叶肉区域积累，幼龄组的三萜酸浓度小于成熟组和老龄组。本研究表明，高光谱成像适用于快速、非侵入式地测定药用植物中活性成分的分布。
