**1. Introduction**

The shelf life, nutritional properties, sensory attributes and microbial quality of food products are important aspects for consumers; therefore, food industries seek to make use of substances or compounds that ensure the safety of their products without compromising their quality [1].

Different preservatives are utilized during food processing to ensure food safety and quality; however, most of them are synthetic, and some have been associated with long-term health problems, such as kidney failure, hyperthyroidism, liver cirrhosis, and cancer, among others [2, 3]. As a result, there is a growing demand for natural products that can serve as preservatives [1].

Essential oils (EOs) are secondary metabolites obtained from different plants, which have been widely utilized as natural preservatives because they are, in many cases, safer than synthetic ones for both humans and the environment [4]. They also have several biological properties including antibacterial, antiparasitic, antifungal, antioxidant, disinfectant, and insecticide ones [5].

Due to their properties, EOs have been utilized in the agri-food industry. They have been applied directly in food systems, either in powder or in liquid form, by means of

edible films or coatings, in vapor phase, as well as in nanoemulsions and liposomes [6]. However, their application in the industry is still limited due to their impact on taste and aroma, especially at the concentrations needed for an effective use as antimicrobial. Therefore, the most acceptable concentration in terms of both, safety and food quality will depend on the type of EO, as well as its active compounds, the type of food in which it is incorporated, the method of application, and the food processing technique [7].

Therefore, the aim of this work is to compare current literature reporting several methods of application of EOs, describing their fundamentals, advantages and disadvantages, and especially their effect on sensory attributes in different food systems.
