## 4 Discussion
### Study on Red Fruits and the Implementation of Cutting-Edge Edible Coating
#### 4.3.2 Formulation of Edible Coating for Red Fruits Application  
Edible coatings are primarily categorized into three primary types. Coatings can be made from various types of materials, including polysaccharides (such as starch, chitosan, cellulose, alginate, pectin, and gums), proteins (such as zein, whey protein, wheat gluten, casein, soy protein, egg albumin, and gelatin), lipids (such as waxes and fatty acids), and composite materials. Moreover, coatings can be formed by combining multiple substances together [129; 130]. Table 2 provides a summary of the several edible coatings that have been applied to red fruits, as documented in the literature. Polysaccharides are naturally occurring polymers that are used in the production of edible coatings. Polysaccharide-based coatings for food preservation often use starch, gums, and chitosan as fundamental constituents [130]. The use of these coatings offers several benefits, such as cost-effectiveness and enhanced accessibility. Although several polysaccharides exhibit reduced water vapor barrier properties, polysaccharides like alginate and carrageenan are notably hygroscopic and possess thick film characteristics. The polysaccharide-based edible coating presents both antioxidant and antibacterial properties [130]. Protein-based edible coatings are derived from both plant and animal sources. Examples of plant-based protein coating materials include zein (derived from maize), soy protein, gluten (obtained from wheat), and other similar substances. On the other hand, animal-based protein sources encompass whey protein, milk protein casein, egg albumin, and gelatin [130]. They exhibit a significantly greater ability to create a barrier against mechanical strength, organoleptic and aroma retention, and high oxygen permeability. However, they do not possess a moisture barrier due to their hydrophilic properties, which can be enhanced by incorporating hydrophobic substances like lipids [130]. Edible coatings made from lipids, such as acetylated monoglycerides, waxes, vegetable oils, or minerals, enhance the appearance of fresh fruit by giving it a shiny and glossy appearance. Lipid coatings, being hydrophobic, may effectively mitigate the effects of oxygen, water, light, and other environmental factors on the quality of stored products. Additionally, they can reduce the rate of water evaporation from food items [130]. In addition, they provide protection against the detrimental effects that mostly occur in cold storage facilities [18; 130]. In a recent study by [PERSON] et al. [130], there has been a significant focus on developing bilayer or composite coatings that include polysaccharides, proteins, and/or lipids. The aim was to enhance the functional quality of these coatings. Every covering substance has a unique but limited role. The combination of two different coating ingredients may enhance the functionality. The main purpose of composites is to maximize the performance of the combination while maintaining the stability of the individual components [130]. The combination of several materials may lead to the development of composite edible coatings that possess distinctive characteristics.