Composition of Beer by ¹H NMR Spectroscopy:  Effects of Brewing Site and Date of Production

Abstract

A principal component analysis (PCA) of 1H NMR spectra of beers differing in production site (A, B, C) and date is described, to obtain information about composition variability. First, lactic and pyruvic acids contents were found to vary significantly between production sites, good reproducibility between dates being found for site A but not for sites B and C beers. Second, site B beers were clearly distinguished by the predominance of linear dextrins, while A and C beers were richer in branched dextrins. Carbohydrate reproducibility between dates is poorer for site C with dextrin branching degree varying significantly. Finally, all production sites were successfully distinguished by their contents in adenosine/inosine, uridine, tyrosine/tyrosol, and 2-phenylethanol, reproducibility between dates being again poorer for site C. Interpretation of the above compositional differences is discussed in terms of the biochemistry taking place during brewing, and possible applications of the method in brewing process control are envisaged.

Nuclear Magnetic Resonance and Headspace Solid-Phase Microextraction Gas Chromatography as Complementary Methods for the Analysis of Beer Samples

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Quantification of acesulfame potassium in processed foods by quantitative 1H NMR

“…In particular, quantification using 1 H NMR (qHNMR) is widely applied in the quantification of medicines [11,12], beverage components [13,14], and natural products in medicinal plant extracts [15][16][17] due to its high sensitivity and the widespread presence of 1 H nuclei in organic molecules [18]. In qHNMR, the content or concentration of the analyte is determined using the ratio between the integral values of a specific signal of the analyte to that of an internal standard (IS).…”

Modulation of La Crosse Virus Infection in Aedes albopictus Mosquitoes Following Larval Exposure to Coffee Extracts

“…The variation seen between these two brands and formulations of coffee is most probably due to the different origins and degree of roasting of the coffee beans that may contain different concentrations of whatever compound(s) has the antiviral and/or larvicidal activity. Such variation in coffee compounds that have antibacterial activity has been shown among different coffee brands (Almeida et al, 2006). However, we did not attempt to identify or quantify the specific active compounds in this study.…”