可见/近红外漫反射光谱无损检测磨盘柿果实硬度的研究

Study on nondestructive measurement of firmness of Mopan persimmon using visible and near infrared diffuse reflection spectroscopy

建立可见/近红外光谱与磨盘柿果实硬度之间的数学模型,评价可见/近红外光谱技术无损检测磨盘柿硬度的应用价值。在可见/近红外光谱区域(570～1848nm),实验对比分析了不同数学建模算法、不同导数处理方法和不同散射及标准化处理的磨盘柿果实硬度定标模型。结果表明,应用偏最小二乘回归算法、一阶导处理和标准正常化和散射处理所建柿果实硬度定标模型的预测性能较优,模型的相关系数(Rc2)为0.7992,均方根误差(RMSEC)为2.0642;用该模型对40个预测样本进行预测,其相关系数(Rp2)为0.8267,预测均方根误差(RMSEP)为2.0223。研究表明,可见/近红外漫反射技术对磨盘柿果实硬度的快速无损检测具有可行性。

To establish mathematical relationship between visible and near infrared diffuse reflection （VIS/NIR） spectroscopy and firmness of Mopan persimmon, and to evaluate the applicability of VtS/NIR spectroscopy technique for nondestructive measurement of firmness of Mopan persimmon.In the spectral region between 570-1848nm, calibration results for firmness of Mopan persimmon were compared with different regression techniques, different derivative treatments and different scatter and standard treatments. The results showed that the partial least squares（PLS）model,with respect to the first derivative D1 lg（1/R）and standard normal variate correction and detrend, provided better prediction performance for firmness of Mopan persimmon, with the correlation coefficient of calibration （ Rc2 ） and the root mean square error of calibration （RMSEC） of 0.7992 and 2.0642 respectively. Using the model to predict 40 samples,the results showed that the correlation coefficient of prediction （Rp2） was 0.8267 and the root mean square error of prediction （RMSEP）was 2.0223.The preliminary research on the built models indicated that nondestructive measurement of firmness of Mopan persimmon using VlS/NIR spectroscopy technique was feasible.