基于近红外光谱的梨果糖浓度无损检测系统

摘要

A nondestructive portable detection system for sugar content of pears based on near infrared spectrum is developed, and the relationship between the near-infrared spectrum and sugar contents of pears is established. A nondestructive testing device for sugar content is designed using the laser diode of 850 nm as the background and that of 905 nm as the characteristic source. The model for calibration is set up by the partial least squares （PLS） meth- od. The correlograms between the standard Brix value and predictive value of the calibration set and the prediction set are obtained which give good predictions of the sugar content of pears, with corresponding r values of 0. 991 9 and 0. 826 2, and standard errors of predictions of 0. 002 and 0. 008. It is proved that the device designed can be used for nondestructive testing of the sugar content of pears of the same variety.%应用近红外光谱漫发射技术设计了梨果的糖浓度无损便携式检测系统，建立了近红外光谱和梨的糖浓度值之间的关系。以850nm激光二极管作为背景光源，905nm作为特征光源，设计了用于梨的糖浓度无损检测的便携式仪器。将校正集样本结合偏最小二乘法进行建模，并对预测集进行预测。同时使用标准仪器测得梨果糖度标准值，得到了标准糖度值和预测值之间的相关图。其中校正集相关系数为0．99186，RMSEC为0．00175，由此模型进行预测时所得到的预测集相关系数为0．8262，RMSEP=0．00808。实验初步证明，文中所设计仪器可对同一种类的梨的糖浓度进行无损测量。