Horsemint (Mentha longifolia (L.) L.) is a less studied, wild-growing species. Aim of the experiments was to define effective extraction method providing highest antioxidant capacity and polyphenol content from the plant, for long-term goal of food preservation uses.

We applied Soxhlet and ultrasonic (US) extraction, both with methanol (MeOH) and ethanol: water in 7:3 (WA) as solvents. Thirty-six accessions were analysed for total phenolic content (TPC) by Folin-Ciocalteu method and antioxidant capacity (AOC) by DPPH and FRAP assays.

The TPC of samples showed that the result of extraction methods is dependent on the solvent: MeOH extracts produced higher values by the US method while WA extracts gave better contents by Soxhlet. Concerning radical scavenging activity (DPPH) and ferrous reducing activity (FRAP), both values were higher in samples produced by US extraction method using WA as solvent. Large variability of TPC and AOC of the 36 plant samples indicates high diversity in polyphenol composition.

薄荷（Mentha longifolia（L.）L.）是一种研究较少的野生植物。实验的目的是确定有效的提取方法，以从植物中获得最高的抗氧化能力和多酚含量，以长期保存食品。

我们应用了索氏提取和超声（US）提取，均以7：3（WA）的甲醇（MeOH）和乙醇：水为溶剂。通过Folin-Ciocalteu方法分析了36种登录品的总酚含量（TPC），通过DPPH和FRAP分析分析了其抗氧化能力（AOC）。

样品的TPC显示萃取方法的结果取决于溶剂：MeOH萃取物通过US方法产生的值更高，而WA萃取物通过Soxhlet获得的含量更高。关于自由基清除活性（DPPH）和亚铁还原活性（FRAP），在以WA为溶剂的美国萃取法生产的样品中，这两个值均较高。36种植物样品中TPC和AOC的较大差异表明多酚组成具有高度多样性。