Rapid Determination of Amino Acids in Chinese Rice Wine by Fourier Transform Infrared Spectroscopy

Abstract:

The content of amino acid in Chinese rice wine（CRW） is one of the most important indexes to evaluate the quality and flavor of Chinese rice wine. In order to rapidly determine the contents of free amino acids in CRW，the possibility of Fourier transform infrared spectroscopy （FT-IR） for the fast detection of 17 different kinds of free amino acids in CRW wasdiscussed. Synergy interval partial least squares（SiPLS） and genetic algorithm（GA） were used to select the most efficient spectral variables to improve the prediction precision of the classical partial least squares（PLS） model based on the full-spectrum. Compared with the PLS model based on the full-spectrum，the prediction accuracy of model based on the spectral variables selected by SiPLS and GA was significantly improved，especially for cysteine，arginine and proline. In addition，GA-SiPLS model showed the most efficient prediction accuracy to all of the free amino acids，with the correlation coefficient of cross-validation higher than 0.80 and the residual predictive deviation larger than 2.00. The FT-IR combined with efficient variable selection algorithms is confirmed as a useful method to replace the traditional methods for routine analysis of free amino acids in CRW.