Abstract

Glucose and ethanol are critical quality control components in the wine fermentation process. In this study, we present a novel method in which Fourier Transform (FT)-Raman spectroscopy and chemometric techniques are used to quantitatively analyze ethanolic beverages produced by fermentation. Chromium (VI) Oxide (CrO₃) was flame-sealed into a fused silica cuvette and used as external standard. Band ratios between the Raman bands of the target molecule and that of CrO3 were calculated and found to be proportional to the concentration of ethanol and glucose. This method can eliminate factors such as laser power or instrumental effects. After pre-processing the spectra, Principal Component Analysis (PCA) and Partial Least Squares (PLS) were selected as the multivariate calibration models. The prediction models proved to be robust resulting in a desirable mapping between the spectra and output attributes. This method could predict the ethanol and glucose concentrations simultaneously and produced a more linear calibration curve. As a result, there is a great potential to use Raman spectroscopy in wine fermentation process and on line fermentation control.

Keywords:

Partial least squares, principal component analysis, quantitative analysis, Raman spectroscopy, wine fermentation,

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Competing interests

The authors have no competing interests.

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