Antifungal Activity of Menthol, Eugenol and Their Combination against Aspergillus ochraceus and Aspergillus niger In Vitro and in Stored Cereals

Abstract

Aspergillus ochraceus and Aspergillus niger are spoilage and mycotoxin-producing fungi that can contaminate agricultural commodities and derived products. In the present study, menthol, eugenol, and their combination (mix 1:1) were tested to determine their contact and fumigation toxicity against the two fungi. Menthol, eugenol, and their mixture significantly reduced mycelial growth and spore germination at concentrations from 300 to 600 µg/mL, and the inhibitory effects showed clear dose dependence. The minimum inhibitory concentration (MIC) values against A. ochraceus were 500 µg/mL (menthol), 400 µg/mL (eugenol), and 300 µg/mL (mix 1:1), while the MIC values for A. niger were 500 µg/mL (menthol), 600 µg/mL (eugenol), and 400 µg/mL (mix 1:1). Additionally, the analyzed compounds exhibited more than 50% protection against A. ochraceus and A. niger by fumigation of stored cereal grains (maize, barley, and rice) in sealed containers. The binary mixture of menthol and eugenol showed synergistic effects against both fungi in both in vitro direct contact and stored grain fumigation trials. The results of the present study provide a scientific basis for the application of a combination of natural antifungals in food preservation.

Comprehensive antifungal investigation of natural plant extracts against Neosartorya spp. (Aspergillus spp.) of agriculturally significant microbiological contaminants and shaping their metabolic profile

“…Ben Miri et al 55 reported sensitivity of Aspergillus ochraceus and A . niger to menthol and eugenol, common constituents derived from mint or myrtle.…”

“…Some reports also focus on reduction in aflatoxin synthesis, spore germination and mycelium growth of Aspergillus flavus under the influence of natural extracts (e.g. Shirazi thyme and cumin seed) 55 . In our research, natural extracts (lavender and marigold dry extracts; lavender, tea tree, clove and rosemary oils) caused an inhibition of Neosartorya sp.…”

The one-humped camel: The animal of future, potential alternative red meat, technological suitability and future perspectives

“…The consumption of these probably contaminated final products may pose a risk to the consumer and some studied samples were heavily contaminated with aflatoxins at levels higher than the limits prescribed by European Union (EU) regulations (4 μg/kg) (EU, 2010). The implications of aflatoxins go beyond the public health aspect but also commercial and economic ramifications ( Belasli et al 2023 ; Ben Miri et al 2023 ). Mitchell et al (2016) estimate that aflatoxin contamination could result in losses to the cereal industry up to US$1.68 billion per year in the United States (U.S.) due to climate change.…”

Nature-Inspired Compounds: Synthesis and Antibacterial Susceptibility Testing of Eugenol Derivatives against H. pylori Strains

“…Although it is abundant in cloves ( Syzygium aromaticum ), it can also be found in various plants, giving them its typical pleasant odor and taste. The high value of this compound and its derivatives in the medicinal chemistry field is justified by its multifaceted activities, including its broad-spectrum antibacterial [ 7 , 8 ], antioxidant [ 9 , 10 ], antifungal [ 11 , 12 , 13 ], antiviral [ 14 , 15 , 16 ] and antiprotozoal [ 17 ] properties, among its many others [ 18 , 19 , 20 ].…”