Characterization of Fen-Daqu through multivariate statistical analysis of H NMR spectroscopic data

Abstract

Fe n liquor is typical of Chinese light-flavour liquor (alcoholic spirit), which is fermented from sorghum with Fen -Daqu powder. Fe n -Daqu is a saccharifying agent and fermentation starter in this fermentation process and in Fe n traditional vinegar. To investigate the changes of biochemical components in Fen -Daqu during the incubation, samples at seven incubation stages were analyzed by 1H nuclear magnetic resonance (NMR) spectrome-try and principal component analysis (PCA). This revealed clear separation of the samples obtained from different incubation stages in the principal component plots by combining PC1 and PC2, which cumulatively accounted for 93.27% of the variance. The major compounds that contributed to discrimination were acetate/alanine, arginine, ascorbate, betaine, choline, ethanol, fructose, galactose, glucose, glucitol, glycerate, lactate, maltose, mannitol, phenylalanine, proline, propylene glycol, threonine and tryptophan. These compounds were regarded as the representative metabolites or biomarkers characteristic for each incubation stage and were related with microbiological changes of importance for quality control in Fe n-Daqu production. © 2011 The Institute of Brewing & Distilling.