Essential Oils for Preserving Perishable Foods: Possibilities and Limitations

Since the middle ages, essential oils (EOs) have been widely used for bactericidal, virucidal, fungicidal, antiparasitical, insecticidal, medicinal and cosmetic applications. Nowadays, it is well known that EOs can enhance the shelf life of unprocessed or processed foods because of their antimicrobial nature. Nevertheless, very few preservation methods based on EOs utilization are implemented until now by the food industry.

The aims of this chapter are: 1) to make an overview of the current knowledge on the antibacterial activity of EOs; 2) to describe their possible modes of action; 3) to evaluate possibilities and limitations of their use in the food industry.

In vitro studies have demonstrated antibacterial activity of EOs against a wide range of spoilage and pathogenic bacteria. As EOs comprise a large number of components, it is likely that their mode of action involves several targets in the bacterial cell, but it is generally recognized that their hydrophobicity enables them to partition in the lipids of the cell membrane and mitochondria, rendering these membranes permeable and leading to leakage of cell contents. A higher concentration is generally needed to achieve the same effect in foods, but studies with meat, fish, milk, dairy products, vegetables and fruits have shown promising results at very low concentrations of EOs (<0.5%, v/w). Toxicological data do not appear to raise concern in view of their current levels of use in foods.

Keywords: What are essential oils, How they act against microorganisms to enhance shelf life of foods, What is their impact on food properties, Legal aspects, safety data and toxicology.