Volatile composition of peppermint (Mentha piperita L.) commercial teas through solid phase extraction

Key findings from this study

This research indicates that:

• Terpenes constituted 89 percent of total volatiles in peppermint tea extracts, measuring 275-382 micrograms per kilogram.
• Solid phase extraction revealed 16 compounds not previously reported in peppermint tea, including dodecane, acetoin, acetol, citral, geraniol, and octanoic acid.
• The volatile profile of aqueous peppermint tea extracts differs substantially from essential oil composition, with apparently lower terpene proportions.

Overview

This study analyzed the volatile composition of aqueous extracts from commercial peppermint tea sachets prepared under conditions simulating home tea preparation. The research employed solid phase extraction with Porapak Q adsorbent followed by gas chromatography with flame ionization detection and mass spectrometry to isolate and identify volatile compounds. The investigation aimed to characterize the aroma profile of peppermint tea as consumed rather than the essential oil profile typically studied through distillation methods. Six different commercial brands were examined to establish the volatile fraction composition in the final beverage.

Methods and approach

Commercial peppermint sachets were infused in boiling water for 10 minutes, filtered, and passed through Porapak Q solid phase extraction traps. Volatiles were desorbed using acetone and analyzed by gas chromatography with flame ionization detection and mass spectrometry. The sample preparation replicated homemade tea conditions to characterize the beverage as consumed. This extraction approach differed from conventional distillation methods used for essential oil analysis. Six different commercial brands were analyzed to assess volatile composition across products.

Results

Terpenes constituted the major volatile fraction at 275-382 micrograms per kilogram, representing 89 percent of total volatile composition. Short and medium chain carboxylic acids (C2-C12) and ketones ranged from 50-64 micrograms per kilogram. Aliphatic alcohols and acyclic hydrocarbons measured below 6 micrograms per kilogram. The analysis identified 16 compounds not previously reported in peppermint tea, including dodecane, acetoin, acetol, citral, geraniol, and octanoic acid.

The proportion of terpenes in the aqueous extract appeared lower than in peppermint essential oil. The authors attributed the detection of previously unreported compounds to the use of solid phase extraction rather than distillation methods employed in earlier studies. The volatile profile suggested that chemical properties of peppermint essential oil may not be fully reproduced in homemade tea preparation.

Implications

The detection of 16 previously unreported volatile compounds demonstrates that extraction methodology substantially influences which constituents are identified in peppermint tea. Solid phase extraction revealed compounds not accessible through simultaneous distillation and extraction, the method used in prior studies. This finding suggests existing volatile profiles of peppermint tea remain incomplete and dependent on analytical approach. The lower terpene proportion in aqueous extracts compared to essential oils indicates that consumers do not experience the complete essential oil composition when drinking tea. Water extraction selectively transfers certain volatile fractions while leaving others in the plant material.

The discrepancy between essential oil composition and aqueous extract composition has implications for understanding the relationship between peppermint chemical properties and tea consumption. Bioactivity studies based on essential oil profiles may not accurately predict effects from tea consumption. The methodological approach establishes that characterizing beverage aroma requires extraction conditions matching actual preparation rather than relying on essential oil data. Future investigations of peppermint tea should consider that the volatile fraction reaching consumers differs substantially from that obtained through distillation of plant material.

Scope and limitations

This summary is based on the study abstract and available metadata. It does not include a full analysis of the complete paper, supplementary materials, or underlying datasets unless explicitly stated. Findings should be interpreted in the context of the original publication.