Quality and Safety Assessment of Commercial Peppermint Teas Based on Essential Oil Yield and Composition

Peppermint tea is one of the most widely consumed herbal beverages worldwide, yet limited data are available on the chemical variability and quality of commercial products. This study assessed the essential oil (EO) yield and composition of 39 commercial peppermint (Mentha × piperita L.) teas and commercial EOs obtained from different countries. EO yield showed pronounced variability, ranging from 0.8 to 26.8 mL/kg. In total, 112 compounds were identified by GC-MS, accounting for 88.4–99.5% of the total EO composition. The major constituents were menthol (0.1–25.2%), menthone (0.1–21.8%), and carvone (0.6–30.0%), revealing marked chemical heterogeneity among marketed products. Several samples exhibited unusually high carvone levels accompanied by reduced menthol and menthone contents, reflecting substantial chemotypic diversity and inconsistency among marketed products. The concentrations of the regulated constituents, pulegone (0.02–2.56%) and menthofuran (0.02–6.58%), remained within the European Pharmacopoeia limits. Based on the observed levels of pulegone and menthofuran, the results do not indicate a safety concern for consumers under normal tea preparation and consumption conditions. Overall, the findings demonstrate substantial variability in the quality of commercial peppermint teas and highlight the relevance of essential oil profiling as a tool for assessing the quality and safety of herbal beverages.