Food safety is one of the most important
issues in food industries since there are always concerns about the outbreak of
foodborne illnesses among food manufacturers, regulatory agencies, researchers
and consumers apart from food stuff spoilage. Therefore, producing safe food is
one of the most important priorities in the food industry (Mohamed et al., 2013).
To ensure food safety there are different methods, including thermal
processing, lowering of water activity, various methods of packaging,
irradiation, high pressure, high-intensity pulsed electric field processing and
the addition of chemical preservatives (Jeong et al., 2014). Synthetic
preservatives are now being replaced by natural preservatives as the natural
preservatives are safer than the synthetic ones (Zantar et al., 2014).
Essential oils (EO) are lipophilic liquids, extracted from various plants
containing different natural, biologically active components; they have
antimicrobial and antioxidant properties (Yousefi et al., 2017). The
antimicrobial properties of essential oils against a wide range of
microorganisms have been confirmed in various studies (Jeong et al., 2014). Due
to the hydrophobic properties of essential oils’ components, they easily pass
through the bacterial cell membrane interfering with molecular transport
mechanisms thereby leading to cell inactivation (Goñi et al., 2009). Generally,
essential oils are more efficacious towards Gram-positive than Gram-negative
bacteria due to the lipopolysaccharide barrier in the outer membrane of
Gram-negative bacteria (Techathuvanan et al., 2014; Tehrani, 2015).
Essential oils showed different fungistatic and fungicidal activities when
tested by direct application and in the vapor phase (Nasim et al., 2017).
Therefore, essential oils have antibacterial and antifungal activities against
different microorganisms, so the aim of this paper is to review research
articles that were done on the antimicrobial properties of essential oils which
were derived from different plant sources.