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Qualitative and Quantitative Control of Carbonated Cola Beverages Using 1H NMR Spectroscopy
journal contribution
posted on 2015-12-16, 21:11 authored by Pauline Maes, Yulia B. Monakhova, Thomas Kuballa, Helmut Reusch, Dirk W. Lachenmeier1H Nuclear magnetic resonance (NMR) spectroscopy
(400
MHz) was used in the context of food surveillance to develop a reliable
analytical tool to differentiate brands of cola beverages and to quantify
selected constituents of the soft drinks. The preparation of the samples
required only degassing and addition of 0.1% of TSP in D2O for locking and referencing followed by adjustment of pH to 4.5.
The NMR spectra obtained can be considered as “fingerprints”
and were analyzed by principal component analysis (PCA). Clusters
from colas of the same brand were observed, and significant differences
between premium and discount brands were found. The quantification
of caffeine, acesulfame-K, aspartame, cyclamate, benzoate, hydroxymethylfurfural
(HMF), sulfite ammonia caramel (E 150D), and vanillin was simultaneously
possible using external calibration curves and applying TSP as internal
standard. Limits of detection for caffeine, aspartame, acesulfame-K,
and benzoate were 1.7, 3.5, 0.8, and 1.0 mg/L, respectively. Hence,
NMR spectroscopy combined with chemometrics is an efficient tool for
simultaneous identification of soft drinks and quantification of selected
constituents.