Mathematical Modeling And Stability Of FTIR/ATR Spectroscopy Analysis For Sugarcane Initial-Pressed Juice

The mathematical models of quantitative analysis for Brix in sugarcane initial-pressed juice were established and optimized by FTIR/ATR spectroscopy and chemometrics method, and the stability of the models were also discussed. A sort of classified method for the calibration and prediction samples was gotten, which based on predictive effect of the best single-point model with all samples. On this condition, the calibration models were established by single-point regression, direct PLS, Savitzky-Golay smoothing PLS, moving window PLS and moving window MLR with fixed interval, respectively. The model parameters were designed according to the root-mean-square error (RMSEP) and the correlation coefficient (R_P) which were the optimum objective. Through a large number of computer experiments, we selected out the optimum models on a large scale and discussed the stability of models.The results showed that the classified method for the calibration and prediction samples was representative, objective and stable. Savitzky-Golay smoothing method can improve model's predictive accuracy greatly. Moving window PLS method can be used to select the high Signal to Noise Ratio spectra bands. MLR method with fixed interval moving window can be used to select combination wavenumbers effectively and have the best predictive accuracy, so that the complexity of the model was reduced greatly. The RMSEP, RRMSEP and R_P for the best predictive effect of optimum models reached 0.4690°Bx, 2.38%, 0.8456, respectively. The results provided excellent and stable models for quantitative analysis Brix in sugarcane initial-pressed juice by FTIR/ATR spectroscopy technology.