Determination of Three Alcohols in Chinese Dukang Base Liquor by FT-NIR Spectroscopy

Abstract

Alcohols are important aroma compounds in Chinese liquors. In this work, 3-methyl-1-butanol, 1-butanol, and 1-propanol in Dukang base liquor were simultaneously analyzed by gas chromatography (GC) and fourier-transform near-infrared (FT-NIR) spectroscopy. The optimal combinations of spectral intervals for three alcohols were selected for modeling. The calibration models, which are based on FT-NIR spectral variables and the chemical values, were established with partial least square (PLS) and validated using internal cross validation. In calibration set, the coefficients of determination (R 2) for 1-propanol, 1-butanol, and 3-methyl-1-butanol were 95.21, 98.05, and 98.05, respectively; corresponding root mean square errors of calibration (RMSEC) were 0.27, 0.49, and 0.67 mg per 100 mL. In validation set, the R 2 were 94.72, 97.96, and 95.22; the root mean square errors of prediction (RMSEP) were 0.40, 0.81, and 1.35 mg per 100 mL. The results indicated that the correlation between the values determined by GC and the values estimated by the calibration for the three alcohols was excellent. The FT-NIR spectroscopy calibration models, which with good prediction performance and high precision, could be used as a rapid methods for determination of alcohols in Chinese liquor.