Mathematic models for quantitative analysis of Brix and reducing sugars in sugarcane juice with Fourier transform near infrared spectroscopy

Basic on the technique of Fourier transform near infrared (FT-NIR) spectroscopy,the calibration models for quantitative analysis of Brix and reducing sugars in sugarcane juice were developed by using transmission mode and calibrating with partial least square (PLS) algorithm. The determination coefficients (R~2) of the predicted models for Brix and reducing sugars in juice were (0.999 0) and (0.995 3), respectively; the root mean square errors of cross validation were (0.115 0)% and (0.072 2)% for Brix and reducing sugars in juice, respectively. The predictive errors measured by FT-NIR methods were close to those by routine laboratory methods.