Antifungal and Antiochratoxigenic Activities of Essential Oils and Total Phenolic Extracts: A Comparative Study.

Rachelle El Khoury,Andre El Khoury,Anthony El Khoury,Richard Maroun,Hiba Kawtharani,Florence Mathieu,Ali Atoui

doi:10.3390/antiox6030044

Abstract

This study is intended to prevent ochratoxin A (OTA) production by Aspergillus carbonarius S402 using essential oils (EOs) and total phenolic compounds extracted from plants and herbs. The EOs used in this study are the following: bay leaves, cumin, fenugreek, melissa, mint, and sage. As for the phenolic compounds, they were extracted from bay leaves, cumin, fenugreek, melissa, mint, sage, anise, chamomile, fennel, rosemary, and thyme. The experiments were conducted on Synthetic Grape Medium (SGM) medium at 28 °C for 4 days. OTA was extracted from the medium with methanol and quantified using HPLC (High Performance Liquid Chromatography). Results showed that EOs had a greater impact than the total phenolic extracts on the OTA production. Reduction levels ranged between 25% (sage) and 80% (melissa) for the EOs at 5 µL mL−1, and 13% (thyme) and 69% (mint) for the phenolic extracts. Although they did not affect the growth of A. carbonarius, total phenolic extracts and EOs were capable of partially reducing OTA production. Reduction levels depended on the nature of the plants and the concentration of the EOs. Reducing OTA with natural extracts could be a solution to prevent OTA production without altering the fungal growth, thus preserving the natural microbial balance.

Highlights

Ochratoxin A (OTA) is a mycotoxin produced by several species belonging to the Aspergillus and Penicillium genera
The cumin, fenugreek, and sage phenolic extracts increased the fungal weight instead of reducing it, by 30.3% for the cumin and 22% for the fenugreek and sage. These weight increments were in correlation with the sporulation of A. carbonarius that was increased by these extracts, whereas the phenolic extracts of the bay leaves, melissa, and mint did not significantly reduce the fungal weight of Concerning the ochratoxin A (OTA) production, both phenolic extracts and essential oils (EOs) acted differently when added to
Some EOs at 1 and 5 μL mL−1 severely affected the OTA, while the phenolic extracts had a mild impact on the production of that toxin

Summary

Introduction

Ochratoxin A (OTA) is a mycotoxin produced by several species belonging to the Aspergillus and Penicillium genera. Its presence in common foodstuff and beverages has aroused significant public concern. More this toxin can be found in numerous food crops, such as cereals and cereal by-products [1], grapes and grape by−products [2], spices [3], and coffee [4]. The greatest concern about this food contaminant lies within its nephrotoxic, carcinogenic, teratogenic, and immunotoxic effects on human health following its ingestion [7,8,9]. The International Agency for Research on Cancer has enlisted the OTA in the group 2B as a possible human carcinogen [10].

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