# Sustainability in Bio-Based Edible Films, Coatings, and Packaging for Small Fruits
## 3 Biological Sources of the Compounds Used in Films, Coatings, and Packaging
### Marine Processing By-Products
Additionally, incorporating marine by-products into packaging can improve their tensile strength and flexibility, making them more durable and practical [29]. Materials from Fish and Shellfish  
Biopolymers derived from fish and shellfish offer an eco-friendly alternative to synthetic plastics, addressing environmental concerns and enhancing food preservation. There are different types of biopolymers from fish and shellfish. Fish gelatin is a prominent biopolymer used for developing biodegradable films. It is valued for its film-forming capacity and ability to protect food against drying, light, and oxygen. Fish gelatin films can be enhanced with other biopolymers like soy protein isolate, oils, fatty acids, and polysaccharides to improve their physical properties and add functional attributes such as antimicrobial and antioxidant activities [30; 31; 32]. Chitosan, derived from crustacean shells, is known for its antimicrobial properties and film-forming ability. Chitosan-based films can be blended with nanomaterials to enhance their mechanical properties and extend food products' shelf life [28]. Collagen and muscle proteins, extracted from seafood processing byproducts, are used to create robust and sustainable food packaging. They can be combined with antimicrobial agents or antioxidants to prevent food spoilage and chemical deterioration [25]. Biodegradable films from fish and shellfish can be incorporated with bioactive compounds such as essential oils, plant extracts, and vitamins to create active packaging. These films release antimicrobial and antioxidative agents, extending the shelf life of perishable foods like fish and meat by inhibiting microbial growth and delaying oxidation [30; 33; 34; 35]. Edible films and coatings made from fish gelatin and other marine biopolymers are used to preserve fresh fish and meat products. These films prevent moisture loss, microbial spoilage, and nutrient degradation, extending the shelf life and maintaining the packaged products' sensory quality [26; 33; 35]. Combining different biopolymers, such as gelatin and myofibrillar proteins, can improve the mechanical and barrier properties of the films. These blends result in intense, flexible films with low water vapor permeability, making them suitable for food packaging [36]. Moreover, eco-friendly crosslinking agents like alginate dialdehyde can enhance fish gelatin films' stability and mechanical strength. This process also improves the films' resistance to moisture and increases their antioxidative capacity [31]. Some authors, such as [36], also mention the possible utilization of nanocomposites. Incorporating nanomaterials into chitosan-based films can significantly enhance their antimicrobial properties and mechanical strength, making them practical for extending the shelf life of various food products. Consumer awareness of the benefits and safety of biodegradable packaging materials should also be increased. Ensuring these materials meet safety standards is crucial for their acceptance [33]. Regarding cost and scalability, developing cost-effective methods for large-scale production of biopolymer-based films is a significant challenge. Innovations in extraction and processing techniques are needed to make these materials commercially viable [26; 33]. Moreover, while biopolymer-based films are biodegradable, their environmental impact during production and disposal must be thoroughly assessed to ensure they are a sustainable alternative to synthetic plastics [25; 32].