## 3 Edible Coatings  
### Formation  
Edible coatings are thin layers or layers of edible material that are applied directly to the surface of the food product, while edible films are placed on top of the product after the film has been formed outside of it [62]. The main functions of edible coatings include protection against mechanical damage, light, or contamination, and acting as a semipermeable membrane and a barrier against gases or moisture [63]. In addition, edible coatings reduce the rate of food respiration, enzymatic browning, and the release of volatile compounds into the environment [64]. Edible coatings are created mostly from aqueous solutions of edible materials such as biopolymers, which provide film-forming capacity and continuous structure when applied to food products. Thus, during the drying process, a uniform layer is developed. Different functional compounds can be added, including plasticisers, antimicrobials, or antioxidants [62]. A better understanding of the mechanism of functional coatings and consumer awareness can contribute to expanding their use to extend the shelf life of fruits and increasing the bioavailability of compounds referred to as bioactive [65]. The primary role of edible coatings is to control moisture loss as well as reduce the rate of undesirable chemical reactions to maintain food freshness, safety, and quality [66]. Also, adding antimicrobials, antioxidants, flavours, or dyes extends the range of their applications [67]. It is increasingly expected that the edible coatings used for fresh fruit will be characterised by high strength, appropriate hydrophobicity, and barriers to gases and light. An important aspect is also the design of coatings that, in addition to improving the taste of products, will comply with the requirements and preferences of consumers; e.g., coatings made with the addition of garlic or ginger, in addition to imparting sensory characteristics, will be an excellent preservative [68]. In the case of edible coatings, two main factors affect their quality: the method of application and the degree of adhesion of the coating to the fruit. One of the methods of applying edible coatings to the product is the immersion method, which consists of placing the sample in a previously prepared coating solution for a certain time (usually from 5 to 30 s), then removing the excess solution and evaporation [69]. In the evaporation stage from the surface of the products, the solvent and excess liquid are removed by heating and drying processes. The advantage of this widely used method is that the product is evenly coated on all sides, even when there is a rough surface. Therefore, the surface properties of the coated product and the nature of the food to be coated also influence the choice of coating method. In the case of fruit, consideration must be given to whether the fruit is climacteric or non-climacteric before applying the edible coating. The conducted research shows that the value of the thickness of edible coatings depends on many properties of the coating solution, e.g., density, viscosity, or surface tension. Observations show that in the case of coating sliced fruit or vegetables, the application of edible coatings is more difficult because the hydrophilic nature of the surface makes it difficult to gel with the coating material of a hydrophobic nature [70; 71]. The immersion method is versatile as it can be used over a wide range of coating solution viscosities. It is usually a method used to apply single-layer coatings, but thanks to technical progress, it is possible to obtain multi-layer coatings, applied alternately for more efficient control and greater coating functionality. A multi-layer coating can be obtained by applying, for example, a polysaccharide or protein solution to the surface of the fruit, drying it, and applying another layer, e.g., a lipid.