Antifungal Activity of Mexican Oregano (Lippia berlandieri Shauer)

Abstract

Antifungal and sensorial properties of spices have been recognized for years. The antifungal compounds are products of the plant's secondary metabolism, and the action of those compounds could be used to inhibit the growth of spoilage and pathogenic microorganisms in food. Mexican oregano (Lippia berlandieri) grows wildly in the desert zone of Mexico and is usually added to regional foods. The goal of this study was to evaluate the antifungal activity of Mexican oregano versus food-contaminant fungi. Fungi were isolated from spoiled fruit and vegetables and identified according to morphological characteristics. The antifungal activity of oregano was evaluated by radial growth measurement on potato dextrose agar added with dried oregano (0.25 to 4.0%). The essential oil antifungal activity of oregano was also evaluated by the diffusion well test. Twenty-one fungal strains were isolated, which included Penicillium, Geotrichum, Aspergillus, and Bipolaris. In seven of the 21 strains, no inhibitory effect was observed at either concentration of oregano. An increase in growth at the lower or higher concentrations of oregano, when compared to the control, was observed in two fungal strains; in 12 strains, a strong inhibitory effect of oregano was evident. The oregano essential oil was inhibitory to all fungal strains, but there were differences in the extent of the effect. Although the antifungal effect of oregano is strongly established, there was a differential effect with the fungal strains studied. Besides pathogenic fungi and bacteria, microbial spoilage flora should be considered when the addition of spices for food preservation is proposed.

Screening of plant-derived antifungal substances useful for the control of seedborne pathogens

“…Essential oils generally were reported as very efficacious in order to reduce in vitro development of several fungi belonging to genus Alternaria (Tian et al 2011), Colletotrichum (Chang et al 2008Arrebola et al 2010;Maqbool et al 2011) and Ascochyta (Zerroug et al 2011). In agreement with our results, oregano essential oil revealed, by in vitro assays, a broad-spectrum antifungal activity vs. a plethora of fungi (Portillo-Ruiz et al 2005).…”

Salt: A Review of its Role in Food Science and Public Health

“…Firstly, from a microbiological aspect they are widely known to possess antimicrobial properties, and studies documenting these properties have been carried out for a range of spices and their essential oils including cinnamon, oregano, thyme, clove and garlic [8,[80][81][82]. Herbs and spices can also impart desirable flavour, colour and texture to the finished product thus minimising any flavour deficits arising from salt reduction [83][84][85]. It is clear that food manufacturers need to investigate their applications in more detail and incorporate these ingredients into their formulations as part of an ongoing salt reduction strategy in processed foods.…”

Extracts of Mexican Oregano (Lippia berlandieri Schauer) with Antioxidant and Antimicrobial Activity

“…This spice has also been demonstrated inhibitory effect against foodborne fungi (Salmeron et al 1990;Araujo et al 2003;Portillo-Ruiz et al 2005) not only on fungal growth but also on the production of aflatoxins and spores. The antimicrobial activity of oregano has been attributed mainly to the presence of volatile compounds found in its essential oil, especially carvacrol and thymol, which have been demonstrated to be responsible for the antimicrobial effect of oregano as individual compounds (Kim et al 1995;Skandamis and Nychas 2000).…”