THE GUARANA GAP: AN ANALYTICAL AND CULTURAL INVESTIGATION OF OVER-SUPPLEMENTATION AND STIMULANT LABELING IN CELSIUS ENERGY DRINKS USING PROTON NMR

Abstract

Energy drinks like Celsius are often perceived as healthy alternatives to more traditional caffeinated beverages due to their thermogenic properties and zero added sugar. However, because energy drinks are classified as dietary supplements, they are not subject to FDA (Food and Drug Administration) pre-market safety or labeling regulations like coffee and soda, limiting transparency regarding ingredients and ingredient potency. An ingredient in Celsius sparked the investigation of this study, known as guarana (Paullinia cupana), due to it containing caffeine as well as other methylxanthine stimulants. This study explores whether the caffeine content listed on Celsius labels accounts for both added caffeine and guarana-derived methylxanthines. Using quantitative proton nuclear magnetic resonance (¹H NMR) spectroscopy, this thesis conducts a proof-of-concept analysis of multiple Celsius samples to quantify caffeine content and investigate potential discrepancies. Caffeine content was calculated by integrating NMR spectral data and scaling from sample tube volume to full can volume. Across the four Celsius samples analyzed, three 355 mL cans and one 473 mL can, measured caffeine levels deviated from labeled amounts. The average measured caffeine values and corresponding 95% confidence intervals were as follows: CS01, 204.75 ± 50.36 mg; CS02, 183.44 ± 33.75 mg; CS03, 156.79 ± 3.46 mg; and CS04, 361.58 ± 16.20 mg. Notably, CS04 exceeded its labeled amount by over 90 mg. The wide intervals observed in CS01 and CS02 reflect variability among replicates and limited sample precision. Theophylline and DMSO standard runs were completed but not analyzed due to time constraints and the proof-of-concept scope; but are recommended for future studies. These findings were made within a limited scope but reinforce the need for improved labeling transparency, stronger regulatory oversight, and further investigation into the combined effects of methylxanthine compounds. Further research with expanded analysis and increased replication is needed to strengthen confidence in these preliminary findings.