Polyphenolic and essential oil composition of Mentha and their antimicrobial effect
Year: 2015
Type: dissertation
Abstract: Mentha plants are used in pharmaceutical and food industries. The genus Mentha has been classified into 18 species, 11 hybrids and hundreds of subspecies, varieties and cultivars. The medicinal and culinary properties of Mentha plants are bounded to the composition of polyphenolic compounds and essential oils. In the present study, the polyphenolic and essential oil composition of 47 Mentha plants. Similar profiling was conducted for 27 commercial peppermint tea samples. This was the first more detailed study to present the composition of mint flavourings isolated from 45 candies and food supplements. For the first time, the effects of peppermint teas water extracts, mint flavouring hydrodistilled extracts and terpenoidic reference substances against respiratory tract pathogen Chlamydia pneumoniae were investigated in vitro. Mentha plants water extracts and essential oils, mint flavouring hydrodistilled extracts and terpenoidic reference substances were tested in vitro for their antimicrobial properties against the potential pathogens Escherichia coli and Staphylococcus aureus. The antimicrobial effects of M. × villosa Huds., M. suaveolens Ehrh., M. × gracilis Sole, M. arvensis L. water extracts and mint flavouring hydrodistilled extracts were studied for the first time on E. coli and S. aureus. The polyphenolics of Mentha plants and peppermint teas water extracts were rather similar. The most abundant compounds found were rosmarinic acid and eriocitrin. Nine polyphenolic compounds were detected for the first time in the plants. The total content and composition of the essential oils in the Mentha plants and commercial peppermint teas samples varied. The essential oil analyses of peppermint teas showed that three tea samples may contain M. spicata L., different from that claimed on the package. The isolated mint flavouring hydrodistilled extract content was higher in mint flavoured sugar candies, pastilles and tablets than in chocolates. The three most abundant flavouring compounds were limonene, menthol and menthone. Peppermint teas water extracts were active against C. pneumoniae. The antichlamydial activity was often related to high content of luteolin and apigenin glycosides. The mint flavouring hydrodistilled extracts and reference substances decreased the infectivity of C. pneumoniae elementary bodies. Antichlamydial activity could be related to the high menthol content in extracts. Mentha plants water extracts showed antibacterial activity against S. aureus. Essential oils and mint flavouring hydrodistilled extracts inhibited the growth of E. coli and S. aureus. Linalool acetate and (-)-carvone were the most active reference substances against both bacteria. This study showed that consumption of Mentha plants may be beneficial for human health.
Source: Työväentutkimus Vuosikirja
Author: Karmen Kapp
Institution: University of Helsinki
Language: English
Subfield: Food Science
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2226533507