基于高光谱技术的茶鲜叶茶多酚含量的估算模型

选取长势、色泽差异较小的9个茶树品种,使用ASD Field Spec Hand Held 2光谱分析仪采集茶树冠层的光谱数据,通过对原始数据进行预处理去除噪音干扰,采用主成分分析方法得到茶树冠层特征波段520、765、821、940 nm,提取特征波段的反射率值,运用多元线性回归、一元线性回归、最小二乘法建立了光谱反射率与茶鲜叶茶多酚含量关系的估算模型。结果表明:最小二乘法模型的决定系数达到0.99;另选23个样品对模型进行验证,真实值与预测值的相关系数为0.97,相对误差为2.99%。

Polyphenols inspecting method of living tea leaves based on hyperspectral reflection

Spectral data was captured for selected different growing and color of nine kind of tea by using ASD Field Spec Hand Held 2 spectrum analyzer. The raw data was pre-processing to decrease noise and improve acquisition. Multiple linear regression analysis, SG and PAC were employed to analysis the data. The optimization model was established to predict the best time of harvesting. The principal component characteristic bands of 520, 765, 821, 940 nm was obtained by smoothing, the first derivative, the second derivative and the pretreatment process. The determination coefficient is close to 0.99 for this model using least square method. By analyzing other 23 kinds of tea to verity the model, the correlation coefficient of real and predictive value is 0.97 as well as the average relative error of 2.99%.