Qualitative and Quantitative Control of Carbonated Cola Beverages Using ¹H NMR Spectroscopy

Abstract

1H 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.

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

“…Although quantification of AceK in cola beverages using 1 H NMR with an external calibration curve was previously reported [24], this report exemplifies the first use of qHNMR to determine AceK levels in various processed foods. Our study demonstrates the advantages of the proposed method including high accuracy, intra-day and inter-day precision, as well as good linearity.…”

QA: Fraud Control for Foods and Other Biomaterials by Product Fingerprinting

“…A recent study on the quality control of cola beverages using NMR is exemplar of the potential application of this technique for food authentication and fraud control [37]. 1 H NMR spectroscopy was used to discriminate with high success between premium and discount cola brands.…”

Low-cost magnetic resonance sensors for process monitoring in the food industry<span></span>

“…Much of the existing literature on exploring foods with MR has focused on the information that imaging can provide [5], or the analysis of spectra [6,7], however studies have been conducted where relaxation times are used to investigate the properties of foodstuffs, such as some oils [8].…”