# A Review of Essential Oils with Anti-Campylobacter jejuni Effects—Their Inhibitory and Destructive Effects on Biofilms and Efficacies on Food Matrices

## TL;DR

This review explores how essential oils can help reduce the presence of Campylobacter jejuni, a foodborne pathogen, in food products.

## Contribution

The paper provides a comprehensive summary of essential oils with anti-Campylobacter effects and their applications on food matrices.

## Key findings

- Clove, oregano, and thyme essential oils were most frequently studied for their anti-Campylobacter properties.
- Essential oils showed efficacy in inhibiting biofilms and reducing C. jejuni in food matrices like chicken and beef.
- Various methods confirmed the antimicrobial effects of essential oils in both in vitro and food-based experiments.

## Abstract

Campylobacter jejuni is an important foodborne pathogen. To prevent human infections, special attention should be paid to prevention. Recently, methods involving essential oils have been considered as a means of reducing the number of contaminants in and on foods. This review summarizes the results of studies in which essential oils (EOs) with anti-campylobacter effects were tested. The most widely studied EOs were clove (28%), oregano (24%), thyme (22%), rosemary (8%), lavender (7%), sage (7%), and tea tree (4%), with other EOs studied to a lesser extent. The anti-Campylobacter efficacies of these EOs were demonstrated in vitro using a broad repertoire of methods, such as minimal inhibitory and bactericidal concentrations, agar diffusion, time-kill assays, adhesion and biofilm inhibitory assays, two-dimensional polyacrylamide gel electrophoresis, quantitative reverse-transcription PCR, and liquid chromatography–mass spectrometry. Recent studies have also focused on the practical application of such EOs, with experiments performed on different food matrices, typically chicken, duck, and beef. The most frequent treatment methods were mixing, dipping, and short-time freezing, either in packed or unpacked forms, and storage at different temperatures (typically 4 °C), although experiments were also performed at 25 °C, 32 °C, and 42 °C using different EO concentrations. In summary, these experiments revealed the anti-Campylobacter effects of thyme, cinnamon, coriander, lime, oregano, chrysanthemum, and basil.