牛奶成分近红外光谱分析中系统漂移的补偿

Compensation of System Drift in Compositional Analysis of Milk by Using Near-infrared Spectroscopy

为实现牛奶中蛋白质、脂肪等成分含量的快速无损检测,本文论述了采用近红外漫反射光谱(1000～1700nm)分析牛奶主要成分含量的基本方法,定量分析了仪器信噪比与系统测量误差之间的传递关系。在此基础上,进一步探讨了采用双光路设计以及参考液光谱自动校正方法消除系统漂移的可行性。实验结果表明:采用参考液光谱自动校正方法可以有效地克服系统漂移,校正后脂肪、蛋白质的实际预测相对偏差(RMSEP)与参考值平均值之比分别降低了0.14%和0.72%。

A method to realize rapid nondestructive examination to the composition of milk by using Near-infrared Scattered reflection spectroscopy(1000～1700nm)was explored,and quantitative relation of signal-to-noise(SNR)and measurement error of the system were analyzed.The feasibility of double light path compensation method and reference solution spectral auto-correction method against system drift during building model and measuring process were respectively researched and experimentally verified.It was concluded that the reference solution spectral auto-correction method could effectively compensate system drift, and the predictive error in practice(ratio of Root Mean Square Error of Prediction(PMSEP)to mean of reference)of fat and protein reduce correspondingly 0.14% and 0.72% after correction with the method,which was useful for improving long-time stability of the measuring system.