# Phytochemical Variability of Mentha L. Species Over Three Growing Seasons

## TL;DR

This study compares the chemical composition of two mint species over three years, finding that Mentha × piperita has higher beneficial compounds than Mentha spicata.

## Contribution

The study reveals genotype-specific phytochemical variability in Mentha species over multiple seasons, emphasizing M. × piperita's superior bioactive potential.

## Key findings

- Mentha × piperita showed higher total phenolic and flavonoid content and antioxidant activity than Mentha spicata.
- Rosmarinic acid was the predominant compound in all samples, with higher concentrations in M. × piperita.
- Genotype strongly influenced phytochemical profiles, while year had a moderate effect.

## Abstract

Species of the genus Mentha are valued for their aroma and bioactivity. This study presents a comprehensive 3‐year (2022–2024) evaluation of two Mentha spicata and three Mentha × piperita genotypes. Methanolic extracts were analyzed for total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activity (AA) using spectrophotometry; individual phenolic compounds were determined by HPLC–DAD, and essential oils (EOs) were characterized by GC–MS. Significant inter‐ and intra‐species variability was observed. M. × piperita showed higher phytochemical levels (TPC: 33.61–55.23 mg GAE/g DW; TFC: 27.56–43.01 mg CE/g DW; and AA: 46.48–103.93 mg TE/g DW) than M. spicata (TPC: 28.92–39.57 mg GAE/g DW; TFC: 23.48–35.11 mg CE/g DW; and AA: 40.09–93.59 mg TE/g DW). Rosmarinic acid predominated in all samples (6227.11 to 29321.70 µg/g DW), with elevated levels observed in M. × piperita. EO yields ranged from 0.55% to 2.31% (v/w), with carvone dominant in M. spicata and menthone, dl‐menthol, or piperitenone oxide in M. × piperita. Principal component analysis confirmed distinct chemical differentiation among genotypes. Genotype had a strong, and year a moderate, effect on phytochemical profiles. These results highlight the species‐specific potential of Mentha for food, pharmaceutical, and cosmetic applications.

Species of the genus Mentha are evaluated over three years for phytochemical composition and bioactivity using spectrophotometric, HPLC‐DAD, and GC‐MS analyses of methanolic extracts and essential oils. Clear genotype‐dependent differences are observed, with Mentha × piperita showing higher phenolic content and antioxidant activity than M. spicata. Genotype has a strong influence, while year has a moderate influence, highlighting the potential of specific species for use in food, pharmaceuticals, and cosmetics.