Chemical composition and antioxidant and antifungal properties of Mentha x piperita L. (peppermint) and Mentha arvensis L. (cornmint) samples

Essential oils and infusions from commercial peppermint sachets (CPS), and non-commercial genuine peppermint (NCP) and cornmint (NCC) samples were analyzed by GC/MS and LC/MS. Minimum inhibitory concentration (MIC) of mint oils against Fusarium moniliforme, Aspergillus niger and Aspergillus fumigates was determined. Antioxidant potential was monitored by total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and soybean oil oxidation tests. CPS and NCC oils had lower menthofuran content than NCP. Mint oils did not show a uniform standard of antifungal activity and they had the modest reducing ability. CPS and NCC infusions showed higher IC50 and lower TPC than NCP ones. In the soybean oxidation test, mint oils presented prooxidant behavior. CPS infusions showed antioxidant potential significantly (P<0.05, Tukey) lower than that from NCC and NCP infusions. NCP infusions were more efficient in delaying propagation reaction than NCC ones. This may be attributed to higher amount of rosmarinic acid and hesperidin in NCP