# Sustainability in Bio-Based Edible Films, Coatings, and Packaging for Small Fruits
## 3 Biological Sources of the Compounds Used in Films, Coatings, and Packaging
### Agricultural Processing Byproducts
#### 3.2.1 Materials from Vegetables and Fruits  
Edible films and coatings derived from plant-based materials have emerged as promising alternatives to conventional packaging, offering sustainable and environmentally friendly solutions for the food industry [42; 43; 44]. These bio-based materials utilize various components, including polysaccharides, proteins, and lipids, each contributing unique properties to the final product. Polysaccharide-based films are particularly relevant in this context, as they can be derived from fruit and vegetable by-products. Polysaccharides like cellulose, pectin, starch, and alginate have attracted significant interest because of their plentiful availability, cost-effectiveness, biodegradability, and excellent film-forming proper ties [44]. Extracted from plant cell walls, cellulose can create strong, transparent films with exceptional mechanical properties [45; 46]. These films exhibit superior mechanical properties and exceptionally high tensile strength compared to many synthetic plastics [47; 48]. This enhanced strength allows for thinner packaging materials while maintaining structural integrity [49]. The optical clarity of cellulose films is another key benefit, making them ideal for food packaging where product visibility is desired [47; 48]. Consumers can quickly inspect the contents without compromising the protective barrier [48]. Perhaps most importantly, unlike conventional plastics, cellulose films are bio-degradable [47; 48; 49]. This property allows them to decompose naturally after disposal, significantly reducing environmental impact and addressing growing concerns about plastic pollution plastics [44; 47]. As cellulose-based films can be derived from abundant plant sources and agricultural by-products, they contribute to resource sustainability plastics [44; 48]. Recent research has focused on improving the functionality of cellulose films by incorporating antimicrobial agents to extend the shelf life of packaged foods plastics [48]. Additionally, cellulose can be combined with other biopolymers or nano-particles to enhance properties such as water resistance and barrier performance plastics [47; 48]. Pectin, commonly found in fruit peels and pomace, forms flexible films with good barrier properties, making it suitable for coating small fruits [42]. Although not derived from grapes or small fruits, alginate, a seaweed-derived polysaccharide, is frequently used in fruit coatings due to its film-forming abilities and compatibility with food products [49]. Protein-based films and coatings have emerged as a promising sustainable alternative to conventional petroleum-based packaging materials. Protein-based films and coatings can be derived from various sources, including animal proteins like casein, gelatin, and whey and plant proteins such as soy, corn zein, and wheat gluten [50]. These materials have shown great potential in extending the shelf life of various food products, including fruits, vegetables, dairy products, and meat [51]. These films offer beneficial properties for food packaging applications, such as excellent gas barrier properties, effectively protecting against oxygen and carbon dioxide [50; 52]. Additionally, they are biodegradable and, in many cases, edible, allowing them to be consumed along with the food product [53]. Another advantage is their ability to incorporate active compounds, such as antimicrobials and antioxidants, to enhance food preservation [50; 54]. Additionally, grape seed proteins extracted from winery by-products show potential for use in film production, although further research is needed to optimize their application [51]. These proteins have demonstrated antioxidant and antimicrobial properties when incorporated into films [55; 56]. In addition, grape seed protein films have shown promising mechanical strength and water vapor barrier properties, making them suitable for food packaging applications [51; 57].