Rapid analysis of acid and ester content in sauce-flavor Baijiu by mid-infrared spectroscopy combined with chemometrics method
The content of total acid and total ester in sauce-flavor Baijiu round liquor was quantitatively analyzed by mid-infrared spectroscopy com-bined with chemometrics method.Standard normal variable(SNV)was used to pretreat the spectrum,and genetic algorithm combined with partial least squares(PLS)and least squares support vector machine(LS-SVM)was used to establish the calibration model,and independent test set samples were used to verify the accuracy of the model.The results showed that the SNV could improve the modeling effect,and the PLS model established by ge-netic algorithm after optimizing the characteristic variables reduced the number of variables of total acid and total ester to 38 and 25 respectively.The LS-SVM model with genetic algorithm preferred wavelength as input variable had better results,the coefficient of determination(R2)of total acid and total ester models was increased to 0.994 and 0.987,respectively,and the root mean square error(RMSEP)of prediction was reduced to 0.031 and 0.082,respectively.The relative percent deviation(RPD)values were 11.94 and 8.05,respectively.Meanwhile,the RPD values of total acid and ester reached 11.94 and 8.05,indicating that the established calibration model had good accuracy and stability,it can quickly detect the content of total acid and total ester in sauce-flavor Baijiu,which provided technical reference for the rapid analysis method of Baijiu quality.
NETL
NSTL
万方数据
维普
