Comparison of Caffeine Content in Coffee and Yerba Mate Prepared According to Traditional Consumption Methods in Argentina

The amount of caffeine provided by a beverage depends not only on its source but also on the preparation method and the amount consumed. In Argentina, coffee and yerba mate are habitual sources of caffeine, yet their actual contribution according to preparation method has not been clearly established. This study quantified and compared the caffeine content of beverages commonly consumed in the country, including espresso and filter coffee, instant coffee, mate cocido, and yerba mate with and without stems across 15 consecutive servings under conditions simulating habitual consumption. Caffeine was determined by high-performance liquid chromatography with diode-array detection (HPLC-DAD). The highest caffeine concentrations were observed in beverages prepared with an espresso machine (225.0–533.9 mg/100 mL), followed by filter coffee (60.2–119.0 mg/100 mL), instant coffee (39.9–60.2 mg/100 mL), and mate cocido (17.3–18.4 mg/100 mL). In yerba mate, total caffeine extraction across 15 servings was 243 mg for samples with stems and 273 mg for stem-free samples. The first four servings provided an amount of caffeine comparable to that of a single espresso. Several preparations exceeded 200 mg per intake, whereas two cups of mate cocido could reach the suggested limit for the pediatric population. These findings show that the preparation method substantially modifies caffeine exposure.