Fluorescence spectroscopy and multivariate methods for the determination of brandy adulteration with mixed wine spirit.

The addition of mixed wine spirit to brandy is easy way to adulterate brandy. To avoid the misleading of the consumers, it is necessary to develop reliable method to detect adulteration of brandy. In this work excitation emission matrix fluorescence in combination with parallel factor analysis (PARAFAC) and partial least squares (PLS) regression was used to determine the content of mixed wine spirit in adulterated brandy samples. Excitation emission matrix fluorescence spectra were measured in the emission wavelength range of 485-580 nm and in the excitation wavelength range of 363-475 nm. The model created using PARAFAC-PLS was able to predict the mixed wine spirit level in adulterated brandy with the root mean square error of prediction (RMSEP) value of 1.9% and a square of the correlation (R(2)) between the reference contents and the predicted values of 0.995.