A review on marine collagen: sources, extraction methods, colloidal properties, and food applications Marine collagen, derived from non-mammalian sources like fish, jellyfish, sea cucumbers, crustaceans, and mollusks, is gaining attention for its potential in food and biomedical applications. This review discusses the sources, extraction methods, and colloidal properties of marine collagen, emphasizing environmentally friendly techniques. Marine collagen is characterized by its triple-helix structure and is used in food products for its ability to form gels, films, foams, and emulsions. Collagen from fish, jellyfish, and sea cucumbers has the highest yield and is primarily type I collagen, while crustaceans and mollusks yield lower percentages. Traditional extraction methods using acetic acid and pepsin are time-consuming and may cause sample destruction, but ultrasonication-assisted methods improve yield and structural integrity. Recent advancements include the use of deep eutectic solvents, supercritical fluid extraction, and extrusion-hydro-extraction to enhance collagen recovery and reduce environmental impact. Marine collagen is used in food applications such as biodegradable films, stabilizers, foaming agents, and micro-encapsulating agents. It is also used in beverages, dairy products, and meat-based items to improve stability, consistency, and elasticity. The review highlights the potential of marine collagen in various food and biomedical applications, emphasizing its advantages over terrestrial collagen, including lower denaturation temperature, reduced disease transmission risk, and simpler extraction methods. The study also discusses the challenges in collagen extraction and the importance of optimizing extraction conditions for maximum yield and quality. Overall, marine collagen is a promising resource for the food industry due to its functional properties and environmental benefits.A review on marine collagen: sources, extraction methods, colloidal properties, and food applications Marine collagen, derived from non-mammalian sources like fish, jellyfish, sea cucumbers, crustaceans, and mollusks, is gaining attention for its potential in food and biomedical applications. This review discusses the sources, extraction methods, and colloidal properties of marine collagen, emphasizing environmentally friendly techniques. Marine collagen is characterized by its triple-helix structure and is used in food products for its ability to form gels, films, foams, and emulsions. Collagen from fish, jellyfish, and sea cucumbers has the highest yield and is primarily type I collagen, while crustaceans and mollusks yield lower percentages. Traditional extraction methods using acetic acid and pepsin are time-consuming and may cause sample destruction, but ultrasonication-assisted methods improve yield and structural integrity. Recent advancements include the use of deep eutectic solvents, supercritical fluid extraction, and extrusion-hydro-extraction to enhance collagen recovery and reduce environmental impact. Marine collagen is used in food applications such as biodegradable films, stabilizers, foaming agents, and micro-encapsulating agents. It is also used in beverages, dairy products, and meat-based items to improve stability, consistency, and elasticity. The review highlights the potential of marine collagen in various food and biomedical applications, emphasizing its advantages over terrestrial collagen, including lower denaturation temperature, reduced disease transmission risk, and simpler extraction methods. The study also discusses the challenges in collagen extraction and the importance of optimizing extraction conditions for maximum yield and quality. Overall, marine collagen is a promising resource for the food industry due to its functional properties and environmental benefits.