Fish waste collagen: a sustainable bioresource for innovative functional foods and nutraceuticals

1 Introduction

The global fishing industry generates million tons of waste annually, including skins, bones, scales, fins, and viscera, which are often discarded, leading to environmental pollution and resource depletion. Globally, over 100 million metric tons of fish waste annually pose significant environmental issues due to improper disposal practices, resulting in pollution and excessive landfill use (FAO, 2023). India, a major contributor to global fish production, with an output of 14.73 million metric tons in 2020-21, confronts a critical challenge in fish waste management (FAO, 2023). The majority of trash is either discharged into aquatic ecosystems or transformed into low-value products such as fishmeal, leading to the insufficient use of a potentially profitable resource (Bhattacharya et al., 2022). In India alone, aquaculture discards represent a vast, underutilized source of protein, with processing operations generating approximately 30–35% (w/w) of waste materials (Maschmeyer et al., 2020). As the most abundant structural protein in the extracellular matrix, collagen provides essential tensile strength to connective tissues such as skin and bone (Cao et al., 2024). Extracting this protein from fish waste offers a sustainable and safer alternative to traditional bovine and porcine sources, which are often restricted by religious dietary laws and the risk of zoonotic diseases such as bovine spongiform encephalopathy (Isnaini et al., 2024; Xu et al., 2021). Furthermore, marine-derived collagen exhibits superior bioavailability and lower immunogenicity compared with its terrestrial counterparts (Rajabimashhadi et al., 2023). High-purity yields are achieved through optimized extraction techniques, including acid solubilization, enzymatic hydrolysis, and ultrasound-assisted methods with sonication-assisted protocols, reaching yields as high as 46% (Farooq et al., 2024; Xu et al., 2019).

The biological properties of fish collagen make it indispensable in regenerative medicine and pharmaceutical development (Lin et al., 2018). Its ability to promote cell adhesion and proliferation facilitates the creation of scaffolds for wound healing and tissue engineering (Mathew‐Steiner et al., 2021; Sen et al., 2025). Additionally, its capacity to form hydrogels and nanoparticles allows for the controlled release of therapeutic agents, enhancing drug delivery efficacy (Arun et al., 2021). These advancements are driving a global market for collagen that is projected to reach $18.7 billion by 2030 (Sen et al., 2025). In the food industry, fish-derived collagen and its peptides are utilized for their gelling, emulsifying, and water-binding capabilities (Farooq et al., 2024; Gómez‐Guillén et al., 2011). These attributes improve the stability, mouthfeel, and shelf-life of protein-enriched beverages and gummies. Furthermore, the film-forming properties of collagen enable the production of biodegradable, edible packaging that acts as an effective moisture and oxygen barrier, reducing plastic waste (Alfayoumi, 2025). In addition to structural uses, collagen hydrolysates provide functional health benefits, including antioxidant, antihypertensive, and antimicrobial activities, which are increasingly incorporated into nutraceuticals and sports nutrition (Rahaman et al., 2023; Xu et al., 2023). Despite these opportunities, large-scale commercialization faces persistent hurdles, including batch-to-batch variability, recovery efficiency, and regulatory hurdles (Rajabimashhadi et al., 2023; Zhu et al., 2022). Future research must integrate biochemical characterization with industrial-scale process optimization to ensure the consistent quality required for high-end biomedical and food applications. This review examines these technological innovations and the growing role of fish waste collagen in fostering a sustainable, health-focused future.

While collagen derived from fish waste has demonstrated extensive applications across the biomedical, pharmaceutical, and cosmetic sectors, the present review focuses primarily on its utilization in the food industry and nutraceutical systems. Particular emphasis is placed on its functional roles as a food ingredient, including its gelling, emulsifying, and film-forming properties, as well as its incorporation into functional foods, dietary supplements, and bioactive peptide formulations. Applications related to the biomedical and pharmaceutical domains are discussed only briefly to provide a contextual background and highlight the broader significance of fish-derived collagen. This targeted approach ensures a coherent and in-depth evaluation of its potential as a sustainable bioresource for value-added food and nutraceutical applications.

2 Review methodology

The current review is prepared on the basis of a structured literature search of peer-reviewed publications relevant to fish-derived collagen and its extraction, characterization and utilization in food and nutraceuticals. The literature was identified through major databases, including Scopus, Web of Science, PubMed and Google Scholar. Combinations of keywords such as “fish collagen”, “marine collagen”, “fish-derived collagen”, “food applications”, “nutraceuticals”, “bioactive peptides”, and “functional ingredients” were used to search for relevant publications. The titles and abstracts of the publications were screened for relevance, and full-text reading was conducted. Preference was given to recent studies, but older landmark studies were also included as appropriate. Review articles, original research papers and relevant book chapters published in English were considered. Studies that were not related to fish-derived collagen or did not have clear relevance to food or nutraceutical applications were excluded. The literature selected was then organized thematically to allow for a comparative discussion of applications, functional properties and challenges.

3 Structure and composition of fish-derived collagen

Collagen is a native fibrous protein with a unique triple-helical structure consisting of three polypeptide α-chains (Figure 1), and it is the most abundant protein in the animal kingdom. Collagen is a major structural component that provides mechanical strength and integrity (Shoulders and Raines, 2009; Gómez‐Guillén et al., 2011). Collagen can be converted to gelatin by thermal or chemical denaturation. This process transforms the highly ordered triple-helical structure of collagen into a random coil configuration, resulting in increased solubility. Owing to its excellent gelling, thickening, and stabilizing properties, gelatin is widely utilized in food systems. Hydrolyzed collagen is a shorter polypeptide chain form of collagen that is more digestible and bioavailable. It is obtained from collagen or gelatin through enzymatic hydrolysis (Al Hajj et al., 2024). Controlled hydrolysis and fractionation produce low-molecular-weight collagen peptides with specific biological activities, such as antioxidant, antihypertensive and antimicrobial effects, and are widely used in nutraceutical formulations (Xu et al., 2023; Park and Jo, 2019). These collagen forms differ greatly in terms of structural organization, physicochemical properties and functional applications and therefore should not be used interchangeably. Table 1 provides a detailed comparison of these forms.

Table 1. Comparative characteristics of various collagen types.

Fish collagen, primarily sourced from byproducts such as skin, scales, bones, fins, and viscera, functions as a sustainable and versatile supply of type I collagen, a crucial structural protein employed in the biomedical, pharmaceutical, cosmetic, and food industries (Islam and Solval, 2025). These byproducts, constituting 50–75% of fish weight, are often squandered or inadequately utilized, despite their significant collagen content, particularly in the skin (up to 70% protein) and scales (Vaishnav et al., 2025; Waqar et al., 2025). Unlike traditional mammalian supplies such as bovine and porcine tissues, fish collagen offers distinct advantages, including a diminished risk of zoonotic disease transmission, the absence of religious or cultural restrictions, and more efficient extraction techniques (Gaikwad and Kim, 2024). Recent studies emphasize its biocompatibility, biodegradability, and metabolic compatibility, making it a feasible substitute for mammalian collagen, despite challenges such as diminished heat stability and mechanical strength (Jafari et al., 2020; Awuchi et al., 2022). Collagen, a complex and prevalent structural protein, constitutes approximately 20 to 30% of animal proteins and is found solely in metazoans (Coppola et al., 2021). Higher metazoans have been reported to possess 28 distinct types of collagens (Naomi et al., 2021). Collagen types are categorized on the basis of their basic structures and modes of supramolecular organization. Fibrillar collagens (types I, II, III, V, XI, XXIV, and XXVII) constitute cross-striated fibrils. In mature fibrillar collagen molecules, the collagenous domain of each α chain comprises the repeating triplet sequence (Gly-X-Y) (Revell et al., 2021). Table 2 shows the comparison of the physicochemical, functional, and biological properties of fish collagen with those of other commercially used collagen sources. Fibrillar collagen (type I) is the predominant protein in vertebrates and significantly contributes to the mechanical characteristics of bones, tendons, and skin (Exposito et al., 2010). The principal raw materials for commercial collagen are cattle bones, pig and cow hides, and various byproducts from domestic animals (Makareeva and Leikin, 2014). Moreover, mollusks (including octopuses, squid, cuttlefish, and mussels), echinoderms, sponges, and jellyfish all possess collagen (Matinong et al., 2022). Consequently, the most economical collagen may be derived from fish byproducts. It can be perceived as generating collagen due to its predominant composition of bones, skin, scales, and fins, all of which possess a high concentration of collagen. Fish collagen has considerable benefits over collagen derived from porcine and bovine sources, including a 1.5-fold enhancement in tissue absorption and superior bioavailability (Furtado et al., 2022). Nonetheless, fish collagen has deficiencies in its melting point, mechanical strength, biomechanical rigidity, and rapid degradation rate (Joy et al., 2024). The primary problem associated with the use of fish-derived collagen is the development of a feasible extraction method for commercial application.

Table 2. Comparative assessment of fish collagen and conventional collagens.

Fish scales present hurdles due to their elevated calcium concentration (16–59%) in the form of hydroxyapatite, which requires decalcification with chemicals such as ethylenediaminetetraacetic acid (EDTA) to enable collagen extraction (Jafari et al., 2020). Research on tilapia scales indicates that collagen yields range from 7.5% to 12.3% with modern techniques such as extrusion-hydroextraction, which maintains the amino acid composition and improves water absorption (13.3%) and retention (15%) capabilities (Kuwahara, 2021). Recent research has investigated cross-linking with nanoparticles (e.g., Fe₃O₄) or blending with polymers such as ulvan to increase the mechanical strength and reduce degradation rates, hence increasing the tensile strength and stability for biomedical applications (Huang et al., 2016). Among these raw materials, fish skin is the most extensively employed for collagen extraction owing to its elevated protein content and negligible fat interference. Numerous marine species, such as Rachycentron canadum, Esox lucius, Sardinella fimbriata, Labeo rohita, Gadus morhua, Thunnus obesus, Oreochromis niloticus, and Prionace glauca, have been examined for their collagen content (Zeng et al., 2012; Karthik and Aljallah, 2023). Moreover, invertebrates, including jellyfish, squids, octopuses, sea cucumbers, sponges, and corals, have attracted increasing interest due to their various collagen types. Certain aquatic reptiles, such as soft-shelled turtles, have also been examined. Each source displays distinct physicochemical and biological characteristics and is influenced by species, habitat, age, and tissue type (Lu et al., 2023).

The molecular makeup of fish collagen features a triple-helical structure comprising three polypeptide α-chains, primarily type I collagen, which consists of two α1(I) chains and one α2(I) chain, each approximately 1000 amino acids in length (Amirrah et al., 2022). The amino acid composition includes a recurring Gly-X-Y sequence, with glycine constituting approximately 32–33%, whereas X and Y are predominantly proline and hydroxyproline, comprising 11–14% of the residues (Mohs et al., 2006). These amino acids are crucial for preserving the triple helix through hydrogen bonding, with hydroxyproline augmenting structural stability via water-mediated interactions (Xu et al., 2019). The secondary structure comprises left-handed polyproline-II helices that assemble into a right-handed triple helix in the tertiary structure, which is reinforced by hydrogen bonds and the pyrrolidine rings of proline and hydroxyproline (Shoulders and Raines, 2009). At the quaternary level, collagen molecules aggregate to form fibrils (100 nm in diameter) and fibers (10 μm in diameter), exhibiting tissue-specific dimensions. The diminished hydroxyproline concentration in fish collagen compromises its thermal stability; however, advancements such as enzymatic cross-linking and the application of deep eutectic solvents (DESs) for extraction have improved its functional attributes, facilitating its application in tissue engineering, drug delivery, and sustainable food packaging (Kameshwar Sharma et al., 2024). Compared with mammalian collagen, fish collagen possesses diminished amounts of proline and hydroxyproline, leading to a decreased denaturation temperature (25–35 °C compared with 37 °C for mammalian collagen), hence constraining its thermal stability. Analytical methods such as SDS–PAGE can be used to determine molecular weights of 130–140 kDa for α-chains and 110–120 kDa for β-chains, whereas Fourier transform infrared spectroscopy (FTIR) can be used to identify distinctive amide bands, validating the structural integrity of collagen (Sun et al., 2024).

Collagen has unique mechanical capabilities at several structural levels, from its core monomer (triple helix) to fibrils and fibers, due to its highly structured architecture. Comprehensive research on type I collagen monomers and fibrils has yielded essential insights into their mechanical properties (Shoulders and Raines, 2009). In recent decades, advancements in biophysical and computational techniques, notably atomic force microscopy (AFM), nanomechanical testing, and molecular dynamics simulations, have facilitated the precise characterization of the mechanical properties of collagen at the nanoscale (Stylianou, 2022). Research has demonstrated that the fracture strength of a single collagen triple helix is exceptionally strong, at over 11 GPa, far surpassing that of collagen fibrils (approximately 0.5 GPa) (Rajabimashhadi et al., 2023). This disparity occurs because fibril rupture primarily involves the disruption of weaker intermolecular interactions (e.g., hydrogen bonds and electrostatic forces), whereas breaking a triple helix necessitates unwinding the helical structure and cleaving robust covalent bonds within the polypeptide chains. Recent AFM-based nanoindentation investigations have indicated that the Young’s modulus of type I collagen triple helices varies from 6 to 7 GPa, whereas dehydrated mammalian collagen fibrils display a somewhat reduced modulus of approximately 5 GPa (Kontomaris et al., 2022). Nevertheless, hydration dramatically modifies fibril mechanics, decreasing stiffness via water-mediated plasticization. Furthermore, cross-linkingencompassing both enzymatic (e.g., lysyl oxidase-mediated) and nonenzymatic (e.g., advanced glycation end products (AGEs)) processes—increases fibril rigidity but may induce brittleness when excessive, a significant contributor to tissue aging and conditions such as fibrosis and diabetes (Kamml et al., 2023; McKay et al., 2019). Collagen fibrils exhibit anisotropy, indicating that their mechanical response differs on the basis of the direction of loading. The shear modulus, which is indicative of resistance to sliding deformation, is a vital metric in fibril mechanics. AFM investigations indicate a shear modulus of 30–35 MPa for dehydrated type I collagen fibrils, but hydration diminishes this value due to enhanced molecular mobility (Wenger et al., 2007). Recent research employing high-resolution Brillouin microscopy has confirmed that fibril dynamics exhibit significant sensitivity to hydration and cross-linking density (Pruidze et al., 2023). Computational and experimental analyses indicate that the 300 nm length of type I collagen triple helices is evolutionarily refined to increase fibril strength via effective energy dissipation processes (Domene et al., 2016). Variations from this length, whether shorter or longer, yield mechanically substandard fibrils. The hydroxyproline content in collagen is essential for preserving its triple-helical structure through the formation of intrahelical hydrogen bonds, especially via the pyrrolidine ring. This alteration elevates the denaturation temperature and enthalpy, hence improving the thermal stability (Radmer and Klein, 2006; Rappu et al., 2019; Tang et al., 2017). Recent findings underscore the importance of bound water molecules in preserving collagen stability through the enhancement of hydrogen-bonding networks. Collagen primarily serves to maintain structural integrity and mechanical resilience in connective tissues but is also essential for cell signaling, proliferation, migration, and tissue regeneration (Giannetti et al., 2025).

Recent studies underscore the importance of collagen in immune modulation and wound healing, revealing that its mechanical and biochemical signals influence macrophage polarization and fibroblast activation (Mathew-Steiner et al., 2021). Furthermore, customized collagen matrices are being explored for biomedical uses, including 3D bioprinting and regenerative medicine, where variable mechanical properties are crucial for mimicking native tissue environments (Cao et al., 2024). Recent improvements in multiscale modeling and in situ mechanical testing have provided deeper knowledge of the deformation mechanisms of collagen. The development of bioinspired materials that replicate the hierarchical structure and dynamics of collagen offers promise for next-generation biomaterials (She et al., 2024). Understanding the influence of posttranslational modifications and cross-linking alterations on collagen dynamics is crucial for addressing age-related and pathological tissue degeneration.

4 Extraction methodologies and comparative analysis

The extraction of collagen from fish waste involves several sequential processes designed to remove non collagenous components, solubilize fibrous proteins, and preserve the structural integrity of the triple helix. The general workflow, including pretreatment, extraction, purification, and drying steps, is illustrated in Figure 2, which summarizes the operational stages commonly applied to fish skins, scales, bones, and swim bladders. Table 3 presents a comparative overview of the different extraction methods.

Table 3. Comparative analysis of extraction methods for fish-derived collagen.

The fish processing industry produces large quantities of byproducts (skins, scales, bones, heads, and viscera), which account for up to 75% of the weight of the fish (Gaikwad and Kim, 2024). Type I collagen (a triple helix structural protein) is made from waste products that have been extensively investigated for use in biomedical, pharmaceutical, and cosmetic products (Oslan et al., 2022a; Rajabimashhadi et al., 2023) because of its high bioavailability and absence of the religious and zoonotic problems associated with mammalian wastes. However, marine matrix collagen remains under rigorous extraction to preserve the native triple-helix forms (including the glycine-X-Y repeating line sequences). The X and Y of the sequences are commonly proline and hydroxyproline, respectively (Gutierrez-Canul et al., 2025; Joshi et al., 2026). In addition to the potential for environmental pollution protection, the inexpensive valorization of byproducts (high-quality collagen) may also be performed as an inexpensive substrate in the efficient generation of functional biomaterials. Mineralized tissues (such as those of bones and scales) are generally demineralized in ethylenediaminetetraacetic acid or gentle acid to solubilize the calcium phosphate matrix without protein degradation (Maschmeyer et al., 2020; Upasen et al., 2019). Alkali treatments involving sodium hydroxide may involve separating noncollagenous proteins or pigments, but the exposure to and concentration (and, indeed, their time) is crucial to avoid degradation of collagen fibers (Liu et al, 2015; Lee et al., 2022). Novel pretreatments, such as high-shear mechanical homogenization and fermentation processes, have been reported to develop sustainable technologies to provide preferential matrix permeation and low-cost chemical requirements (Razali et al., 2023). The acid-soluble collagen (ASC) method is one of the most traditional extraction techniques and is widely employed with acetic acid, lactic acid, and citric acid to weaken intermolecular linkages, further increasing the solubility of proteins (Amirrah et al., 2022; Hou and Chen, 2023).

Acetic acid, particularly at a concentration of 0.5 M, has been widely reported as an effective solvent for collagen extraction due to its ability to reduce salt-mediated interactions, disrupt Schiff-base crosslinks, and maintain acidic conditions that inhibit microbial growth (Li et al., 2022; Oslan et al., 2022a). The extraction of skin from purple-spotted bigeye snapper can yield 5.79% collagen in the presence of acetic acid, 4.15% in citric acid, and 3.19% in lactic acid (Oslan et al., 2022a). ASC is not suitable because of its long extraction time (48–72 h) and relatively small total generated collagen, especially when cells have large covalent cross-linking regions (Farooq et al., 2024). Pepsin-solubilized collagen (PSC) extraction involves enzymatic cleavage of the nonhelical telopeptide regions, which enhances collagen solubility and extraction efficiency while preserving the integrity of the triple-helical structure. This process also contributes to characteristic UV–Vis absorption peaks observed near 230 nm (Oslan et al., 2022a; Upasen et al., 2019). Compared with that of ASC, the amount of collagen extracted from surf clam shells by PSC was 3.78% (compared with 0.59% for ASC) (Wu et al., 2019), but PSC from snapper skin-derived PSC had a 6.65% yield with a hydroxyproline factor of 66.3 mg/g and was efficiently extracted from the mature form of collagen, which had active partial recovery in comparison with that of ASC (Oslan et al., 2022b). Process intensification methods leading to the enhancement of collagen extraction are becoming increasingly common, e.g., those of ultrasound-assisted extraction (UAE), where the acoustic cavitation method has been reported to provide high solvent penetration and enhance disruption of the tissue matrix to optimize collagen release from tissues (Farooq et al., 2024). Moreover, this approach has been reported to significantly reduce extraction time, with some studies achieving collagen extraction from European plaice byproducts within 15–35 minutes, compared with the conventional methods that require several days (Kendler et al., 2023). However, the specific process factors need to be controlled because ultrasonically induced heating enhances collagen denaturation in situ (Lu et al., 2023; Razali et al., 2023). Microwave-assisted extraction (MAE) is an emerging extraction technique that utilizes electromagnetic radiation to induce dipolar rotation of water molecules, thereby promoting rapid internal heating and cellular disruption. Compared with conventional extraction methods, MAE is considered more efficient and requires lower solvent consumption (Kendler et al., 2024), but careful temperature monitoring is key to achieving optimal heat stress tolerance to the collagen triple helix, which is inherently more flexural in marine than in terrestrial species. Deep eutectic solvent (DES) systems are potentially the quickest emerging new green extraction technologies and utilize hydrogen bond donors and acceptors to develop liquid systems under ambient conditions (Ali et al., 2026). DES choline chloride with organic acids can extract 89–91% of collagen peptides from cod skin at 65 °C (Maschmeyer et al., 2020). Maschmeyer et al. (2020) reported that a DES system that consisted of xylitol/citric acid and water produced a 2.5-fold increase in blue shark skin collagen recovery capacity and a decreased extraction period from 96 h to 1 h, making the preprocessing requirements even smaller. Sustainable collagen recovery is a research area, and new technologies such as subcritical water extraction (SWE) and supercritical fluid extraction (SFE) have been reported as effective high-pressure processing methods. However, along with the maturation process, another property of SWE, a dielectric constant relatively close to that of organic solvents (Thani et al., 2026), allows selective leached fine toxic deposits from water physicochemical (especially subcritical) processes to be harvested from collagen. However, these two approaches are beneficial but require special equipment and stringent process control and procedures to minimize the hydrolysis of collagen into low-molecular-weight peptides (Razali et al., 2023). Compared with the current methods, many compromises are observed among extraction efficiency, processing time, and structural integrity. On the other hand, existing ASC- and PSC-based methods are commercially viable and are acceptable for the restoration of the original collagen structure but suffer from limited processing time and chemical requirements. In contrast with recent systems such as UAE, MAE and DES, this process has the advantages of increasing the extraction efficiency and sustainability, especially DES, which is the most promising DES because this process has relatively high efficiency before treatment and is less dependent on previous techniques. Therefore, further optimization of process parameters, including temperature, solvent type, and extraction time, is essential for the sustainable large-scale production of collagen-based biomaterials with improved yield and quality within a circular bioeconomy framework.

5 Bioactivity and functional properties of fish collagen

Fish collagen is a bioactive substance that can potentially regulate many cell processes that are important for tissue repair and homeostasis. Zhang et al. (2022) demonstrated that peptides derived from marine mollusks (Pinctada martensii) promoted epithelialization through stimulation of the expression of several growth factors, such as VEGF and FGF-2, and activation of the TGF-β/Smad signaling pathway, which is the main pathway for reparative effects. These claims were significantly expedited in vivo. Hydrolyzed collagen from chum salmon increased wound coverage by 12% in rats and resulted in increased fibroblast infiltration and collagen deposition. Collagen sponge synthesis in giant croaker swim bladders (Nibea japonica) decreases the levels of proinflammatory cytokines (IL-1β, IL-6 and TNF-α), which accelerates the process of wound healing from the inflammatory stage to the proliferative stage (Zheng et al., 2020). They also demonstrated that collagen derived from swim bladders of giant croakers (Nibea japonica) downregulated the levels of inflammatory cytokines, such as IL-1β, IL-6 and TNF-α, thus promoting the tissue transition from the inflammatory phase to the proliferative phase. The biophysical characteristics of fish collagen include these structural and functional plastic properties, and this structural diversity makes it highly versatile.

According to Srinivasan et al. (2025), the molecular weight distribution is often quite broad, and small-molecular-weight (< 10 kDa) peptides are considered more suitable for nutraceutical bioavailability, whereas higher-molecular-weight (>100 kDa) peptides are preferred for structural biomaterials. This material exhibits non-Newtonian rheological behavior, with a gelation temperature of 5–10 °C and a viscosity of approximately 10–15 mPa·s, and due to the amphiphilic nature of fish collagen in food systems, fish collagen is effectively used as an emulsifier (Yang et al., 2026). This finding indicates that its hydrophobic domain also stabilizes the matrix by adsorbing at the oil–water interface. Moreover, it has been employed in transparent, flexible barriers with tensile strengths ranging from 5–50 MPa and is suitable for active packaging. The molecular mechanisms of fish collagen activity have been identified recently. A recent report revealed that hydrolyzed collagen secreted by sea bass skin activates the Akt signaling system and increases the calcium concentration in preosteoblast cells and the activity of RUNX2, which rapidly promotes bone strength. Peptides with small molecular weights, rather than larger protein structures, are optimal candidates for osteoblast growth (Chotphruethipong et al., 2021). Herawati et al. (2022) reported that hydrolyzed collagen inhibits hyperpigmentation and proliferation of melanin in the skin, with IC50 values for antityrosinase activity of ~79.35 ppm, which are lower than those of nonhydrolyzed collagen. It also prevents the formation of advanced glycation end products that decrease the elasticity of the skin due to its high antiglycation activity. In addition, the functional properties of fish collagen are also dependent on its physicochemical stability. Turbot skin gelatin is a renewable alternative to conventional food stabilizers and is very conditional in its properties. Optimized processes have been achieved with a content of less than 30% less than 100 kDa (Valcárcel et al., 2021) and excellent gel stability and rheological properties, resulting in high structural integrity. Furthermore, fish collagen oligopeptides can protect against oxidative stress by stabilizing mitochondrial homeostasis through antioxidative stress, and a new method with which to cure chronic inflammatory diseases in food is medicine (Zhu et al., 2024). Significant therapeutic peptides produced in fish collagen by enzymatic hydrolysis enhance collagen bioactivity. Another therapeutic compound found in fish waste is the 770 Da heptapeptide Gly-Leu-Pro-Leu-Asn-Leu-Pro, which has the same antihypertensive activity as captopril after 6 h of treatment via an ACE-inhibitory IC50 of 18.7 µM (Xu et al., 2023). Some bioactive hydrolysates have antiphotoaging effects (protecting the skin from UV-induced damage), and others seem to have antiobesity effects (modulating the gut microbiota) in relation to their function as bioactive hydrolysates (Xu et al., 2023). However, fish collagen has low thermal stability and is not suitable for high-temperature operation (Srinivasan et al., 2025). Fish collagen has denaturation temperatures between 35 and 40 °C, and mammalian collagen has denaturation temperatures of approximately 40 to 65 °C. Researchers are looking for candidates through chemical crosslinking and composite formulations. Yang et al. (2026) reported considerable improvements in the mechanical strength, water holding capacity and thermal stability of chitosan-containing collagen-based scaffolds. These innovations, as well as nonethical and zoonotic disease, make fish collagen a global substitute for biomaterials that can be developed and do not harm the environment (Jaziri et al., 2025; Oslan et al., 2022a). Table 4 summarizes recent studies investigating the bioactivity and functional properties of fish-derived collagen and collagen peptides, along with their major findings and potential applications.

Table 4. Bioactivity and functional properties of fish-derived collagen.

6 Applications of fish-derived collagen in functional foods and nutraceuticals

Fish-derived collagen is increasingly being positioned as a sustainable substitute for mammalian collagen, also helping valorize processing byproducts and reducing zoonotic and environmental concerns (Shi et al., 2025; Barzkar et al., 2023). In the food industry, it is used mainly as a functional ingredient for gel formation, emulsification, foaming, stabilization, and film/coating development. Recent reviews also describe applications in biodegradable packaging films, edible coatings, food additives, microencapsulation systems, and stabilizers in beverages, dairy products, and meat products to improve texture, consistency, elasticity, and shelf performance (Farooq et al., 2024). In nutraceuticals, fish collagen is commonly used in collagen peptides and hydrolysates for skin health, joint support, and bone-related formulations, and the peptide fractions are also reported to have antioxidant, antihypertensive, antidiabetic, antimicrobial, anti-inflammatory, and anticoagulant activities (Coppola et al., 2020; Laasri et al., 2023). A summary of these applications is presented in Table 5, while Figure 3 provides a schematic illustration highlighting the various functional and industrial uses of fish-derived collagen in these domains. The diverse applications of fish-derived collagen in the food and nutraceutical sectors have been comprehensively discussed in the preceding sections.

Table 5. Application of fish-derived collagen in food and nutraceuticals.

6.1 Nutraceuticals and health supplements

Fish collagen peptides (FCPs) have been shown to be very effective nutraceuticals for skin regeneration on the basis of both clinical and molecular evidence. In a randomized, double-blind, placebo-controlled study (n=72 women, 12 weeks), oral supplementation with tuna-derived collagen peptides significantly improved skin hydration (+13.2%), elasticity (+10.1%), and dermal density while decreasing transepidermal water loss (TEWL) (Morakul et al., 2024). Mechanistically, these clinical benefits are associated with increased synthesis of type I collagen and elastin in human skin fibroblasts. In a 90-day clinical trial, 5 g of fish collagen peptides improved skin health by 59.72%, strengthened nails by 62.50%, and decreased osteoarticular discomfort by 10 g/day, which demonstrated systemic benefits for connective tissue (Sriraam et al., 2025). At the molecular level, Pro–Hyp- and Hyp–Gly-rich fish collagen peptides act as protein signaling molecules and not only amino acids. In an aged mouse model, oral supplementation with rohu (Labeo rohita) collagen peptides at 600 mg/kg improved skin hydration (p < 0.001), wrinkle scores (p < 0.001) and transepidermal water loss (TEWL) (p < 0.05) by increasing the induction of the TGF-β/Smad signaling pathway, an important determinant of ECM synthesis (Kim et al., 2025). Moreover, additional mechanistic features were also obtained through peptide-specific studies: tripeptide-enriched collagen fractions contributed to an increase in dermal collagen levels of ~120% in UV-induced photoaging models and inhibited matrix metalloproteinases (MMP-1 and MMP-3) associated with collagen degradation (Zhang et al., 2025a). Hydrolyzed fish cartilage metabolites have also been verified to directly promote fibroblast proliferation by 35–40% and promote hyaluronan and elastin production, further confirming their importance in skin moisture and stability (Wauquier et al., 2022). The peptides of fish collagen seem to have substantial osteoarticular activity potential, especially in older populations. Clinical studies have shown that daily supplementation with 10 g of fish collagen peptide for a period of 8–12 weeks reduces visual analog scale (VAS) pain levels by approximately 70.86% and improves joint stiffness and mobility in osteoarthritis patients (Sriraam et al., 2025). Collagen hydrolysates enhance chondrocyte proliferation and extracellular matrix regeneration, thus increasing the synthesis of type II collagen and proteoglycans in cartilage tissue. In vitro studies with MC3T3-E1 preosteoblast cells revealed that fish collagen peptides (50–200 µg/mL) significantly increased cell proliferation and alkaline phosphatase (ALP) activity, two key markers of osteogenesis (Chotphruethipong et al., 2021). These effects are modulated by the activated PI3K/Akt signaling pathway and the RUNX2 transcription factor, with implications for osteoblast development and bone matrix deposition. The results of in vivo studies in aging mice revealed that oral treatment with fish collagen hydrolysate significantly increased bone mineral density (BMD) and hydroxyproline and alkaline phosphatase (ALP) activity, which indicated increased bone production and decreased resorption (Chotphruethipong et al., 2021). In addition, fish collagen peptides possess antioxidant characteristics (DPPH scavenging >70%), which is a significant component of OSS-induced cartilage degradation, an associated cause of chronic joint diseases. Compared with that of mammalian sources, the bioavailability of fish collagen is greater. Fish collagen peptides, which are low-molecular-weight (0.3–8 kDa conventionally) peptides, are quickly taken up by the intestinal epithelium. The biobased concentrations of proteins such as Pro–Hyp and Hyp–Gly in plasma (1–2 hours post-consumption) were found to be much greater than those in intact collagen, as evidenced by studies in humans and animals (Zhang et al., 2025b). Functional food systems were found to have improved absorption properties into beverages. Collagen-activated orange juice displayed an in vitro bioavailability of 95.37%, implying that their liquid matrices may be efficient as delivery systems (Farooq et al., 2024). We are developing innovative delivery technologies for the issues of malodorous emissions, instability, and gastrointestinal degradation. Nanoliposomal encapsulation (particle size ~20–200 nm) increases the potency of peptide stability, dispersibility, and sensory acceptability of the compound to bioactive segments by shielding them from enzymatic degradation (Li et al., 2023). Collagen peptides can be encapsulated in an oral film and protected into the enteric layer of delivery systems, which can ensure that the collagen peptides are absorbed directly in the intestine following gastric conditions (pH ~1.5–3.0), where these tissues are ideal for absorption (Farooq et al., 2024). New technologies, such as fish-collagen-based hydrogel microneedles, have swelling capacities of up to 300–340%, leading to controlled release over 24 h so that the scope of their applications has expanded from nutritional application to transdermal drug delivery (Gaikwad and Kim, 2024).

6.2 Edible film and biodegradable packaging

Besides fish skin, other processing by-products are getting recognition as a sustainable source of collagen and gelatin for development of edible films and biodegradable packaging systems with dual functionality for food preservation and delivery of nutraceuticals. These biopolymer-based films show barrier properties against moisture and oxygen and also act as effective carriers for bioactive compounds such as antioxidants, antimicrobials and functional phytochemicals thus improving the nutritional and functional value of food products. Tang et al. (2015) reported the presence of acid-soluble collagens in the skin of tilapia, grass carp and silver carp and showed that collagen from tilapia skin produced films with improved tensile strength (51.24 MPa) illustrating the importance of molecular structure on film performance. In a similar study, Tabari (2017) reported that a mixture of cold-water fish gelatin and carboxymethyl cellulose significantly improved the tensile strength and Young’s modulus while reduced the equilibrium moisture content supporting its application in edible packaging for food quality preservation. The rising demand for modified collagen-based films in modern food systems can be fulfilled by crosslinking and blending techniques to improve the mechanical strength and barrier properties while maintaining compatibility with food matrices. For example, transglutaminase-cross-linked tilapia collagen films had increased tensile strength and decreased water vapor permeability, which is beneficial for the food’s stability, but reduced the elongation at the break (Hou et al., 2023). Similarly, the laccase-catalyzed collagen/delphinidin films had a compact layered structure and superior barrier and mechanical properties compared to the pure collagen films (Yin et al., 2023). Such structural modifications are highly significant for the development of functional food packaging systems capable of extending food shelf life and acting as delivery vehicles for nutraceutical compounds. A major progress in this context is the development of active packaging systems, which combine fish collagen and gelatin films with bioactive agents with antimicrobial and antioxidant effects. Gómez-Estaca et al. (2010) described that fish-skin gelatin–chitosan films containing clove essential oil had antimicrobial activity and extended the shelf life of chilled fish. Mao et al. (2021) also found that essential oil-collagen films were effective for inhibition of bacteria growth in Pacific mackerel fillets during refrigerated storage. Hu et al. (2021) developed collagen-chitosan films from Atlantic cod skin with cinnamon essential oil which displayed significant DPPH radical scavenging activity (48.56%) and antimicrobial activity against E. coli and S. aureus. These findings strongly suggested that such films could be used as packaging materials and nutraceutical carriers for delivering bioactive compounds, which are beneficial for food preservation and health. Recent advances have shown the use of fish collagen films in smart packaging systems for real-time monitoring of food freshness. Yin et al. (2023) incorporated pigment from Vaccinium oxycoccus into collagen/delphinidin films which changed color from purplish-red to grayish-blue during fish spoilage to indicate freshness and extend shelf-life. Mirzaei et al. (2024) proposed CMC-collagen smart films containing nutraceuticals such as quercetin or eucalyptol which improved the mechanical properties and decreased the total volatile basic nitrogen content of packaged fish. These systems are promising for combining nutraceutical functionality with intelligent food packaging for preservation of quality and real-time monitoring of product quality.

6.3 Food emulsifiers, stabilizers, and texturizers

The binding of collagen and gelatin produced from fish can help improve the stability of multiphase food systems through their adsorption at interfaces and increase the longevity of emulsions. Dey et al. (2021) performed mechanistic research and isolated collagen type I from seven fish byproducts to obtain hydrolysates from Pacu skin and tilapia bones with high solubility, significant surface activity, emulsification activity ranging from 53 to 70 m² g^-¹, emulsion stability at 62–85 minutes, and maintenance of the emulsion properties of butter and chocolate sauce for 25 weeks. Previous studies by Santana et al. (2011) revealed that collagen fibers can form stable oil-in-water emulsions at different pH values, protein concentrations and homogenization parameters. Tilapia skin gelatin has been evaluated as a replacement for mammalian gelatin in acid milk gels and low-fat stirred yogurt (Pang et al., 2017), and increasing the gelatin concentration results in greater gel resistance and strength throughout a wider melting process. Xanthan gum-enhanced fish gelatin has the potential to greatly improve water retention and texture in low-fat stirred yogurt, with properties similar to those of porcine gelatin at 0.4 g/100 g (Yin et al., 2021). The fish skin gelatin hydrolysate in the ice cream significantly improved overrun (9.55–21.74%), enhancing the melting resistance and producing pseudoplastic viscoelastic mixtures; therefore, when properly formulated, such gelatin can be successfully employed as both a stabilizer and/or emulsifier to avoid adversely impacting the appearance, odor, flavor, or melting quality. Fish skin gelatin can be used in avocado-based low-fat ice cream to increase protein content and has been found to be an effective agent for good sensory acceptability (Tekle et al., 2025). The FCH of fish collagen hydrolysate has been analyzed as a fat substitute for buffalo patties (formulations with FCH contents between 2.5–10% compared with a full-fat control). Fish gelatin derived from bighead carp bones was used in low-fat mayonnaise, where 40% oil substitution was reported to be efficient in providing a good level of emulsion stability as well as satisfactory sensory characteristics (Ibrahim et al., 2018). Hydrolyzed fish collagen has been added to fruit juice beverages to increase protein levels to 0.56–2.22–2.48 g/100 mL; the orange preparation attained the highest in vitro bioavailability of 95.37%, and 2.5% collagen was the preferred sensory formulation. Fish skin gelatin has also been used in low-fat ice cream to improve protein content and palatability (Bilek and Bayram, 2015).

7 Food safety risks and quality standards of fish waste collagen

The production of collagen from residues from fish processing (skin, scales, bones) represents a sustainable alternative to mammalian sources and is associated with certain food safety concerns in the marine environment and industrial production (Coppola et al., 2020; Rajabimashhadi et al., 2023). Fish collagen is free from the risk of bovine spongiform encephalopathy and terrestrial zoonoses, but it is susceptible to the bioaccumulation of various toxicants and heavy metals (Cutajar et al., 2022; Dondero et al., 2025; Yang et al., 2026), which may transfer into the final consumer without appropriate control (Cammilleri et al., 2025). Early toxicological analysis of commercial fish supplemented with collagen revealed that arsenic was the most abundant contaminant (mean concentration of 0.59 ± 0.28 mg/kg) and was the second most common contaminant (mean concentration of 0.13 ± 0.02 mg/kg). These levels are generally lower than the current EU regulatory recommendations (0.5–1.5 mg/kg in seafood) (Fu et al., 2025; Cammilleri et al., 2025); however, studies indicate that the consumption of more than one supplement may carry a cumulative risk, as the dose widely varies among brands. Heavy metals (zinc, chromium, cobalt and copper) have been detected in certain studies of Atlantic bluefin tuna offal. Compared with those derived from the skin, bone collagen generally contains higher levels of these elements (Cutajar et al., 2022). Mercury and cadmium are also major issues. For example, cadmium levels are in the range of 0.152–0.288 mg/kg in fish collagen, with land-animal counterparts showing significantly higher residue contents and, to some extent, even up to 2.78 mg/kg (Demir and Gülay, 2023). The safety of the final products is also strongly affected by the ecosystem and the species from which the raw materials are obtained. Some toxic elements, such as cadmium and lead, are found in the products of Greenland halibut (Reinhardtius hippoglossoides), although these levels are well below those reported by the European Medicines Agency (ICH guideline Q3D for elemental impurities) (Martins et al., 2022). Concomitantly, studies on protein hydrolysates extracted from cod and salmon skin have shown that the concentrations of mercury and cadmium are generally below detection limits and that arsenic and lead are safe (Wang et al., 2025). However, antibiotic residues, such as chloramphenicol, also remain in a number of fish collagen lots, but such contaminants are below lower detection limits for some samples (Demir and Gülay, 2023). High-resolution analytical approaches, particularly inductively coupled plasma–optical emission spectrometry and high-performance liquid chromatography, are important for determining the absence of inorganic and organic contamination of food-grade collagen (Kržišnik et al., 2024; Martins et al., 2022). On the other hand, allergenicity is one of the major safety concerns, which has prevented the wide adoption of fish collagen in the food industry. Parvalbumin is a highly stable water-soluble muscle protein and a major allergen in most fish species (Koppelman et al., 2012; Kuehn et al., 2014), and it is also the main cause of collagen contamination. Parvalbumin is more commonly low in fish skin than in muscle tissue (0.4 mg/g vs. 6.25 mg/g in cod) but can persist in the absence of proper processing to retain traces (Koppelman et al., 2012). Industrial washing, which is common in the production of fish gelatin, is known to decrease the parvalbumin concentration by approximately 1000-fold to less than 0.5 ppm (Kobayashi et al., 2016). Commercial batches of fish gelatin were subjected to quantitative ELISA, and the majority (77%) of batches contained parvalbumin concentrations less than 0.02 µg/g, which is safe for the majority of fish allergic cases (Koppelman et al., 2012). In addition to parvalbumin, fish type I collagen has emerged as an important independent allergen that can result in IgE-mediated responses (Sun et al., 2024; Wai et al., 2021). Recent clinical data indicate that collagen sensitization is more prevalent than previously believed, with IgE reactivity noted in 21–50% of fish allergy patients (Reginald et al., 2024). For example, when raw fish consumption is common in populations such as those in Japan, the prevalence of sensitization may be as high as 50%, with ∼36% of these individuals showing mono-sensitization to collagen and no reactive antibodies to parvalbumin (Wai et al., 2021). This allergen is very cross-reactive in fish species, including collagen from Pacific mackerel, which has been found to block IgE binding to protein extracts of 22 different fish species, accounting for up to 93% of the total protein content (Wai et al., 2021). It is well known that the collagens of fish and gelatins are very cross-reactive to each other but not to their mammalian (bovine) counterparts due to wide sequence divergence (Kalic et al., 2021). For individuals with a known fish allergy, collagen supplements must be used cautiously. Even highly purified small molecules such as peptides may at least possess a native structure suitable, under certain conditions, to react with IgE to initiate allergies (Kirtil, 2025; Yang et al., 2026). It is thus recommended that the traceability from the fishing boat/aquaculture farm to the final extraction facility (the source) should be expanded so that raw materials can be treated under hygienic conditions to minimize preprocessing deterioration (Dondero et al., 2025). Lipid oxidation and the production of undesirable volatile compounds (hexanal and nonanal) have been reported to occur after processing delays, and this process is thought to affect the sensory profile and demonstrate deterioration in the quality of the raw material (Gou et al., 2024). Hazard analysis and critical control points are the keys to ensuring the safety of the production of fish collagen. At all stages in the collagen production line, the HACCP-based management system includes critical control points: raw material selection, pretreatment (alkaline/acid washing), enzymatic extraction, filtration, drying and storage (Owusu-Apenten and Vieira, 2022). As per the FDA (Fish and Fishery Products Hazards and Controls Guidance), the most significant hazards are pathogenic microorganisms, environmental toxins and chemical pollution, but the recommended preventive controls are temperature control, sanitation and verified processing steps (Jeyasekaran and Shakila, 2023). By HACCP, safety risks are minimized in proactive monitoring instead of in postproduction testing. The last, and perhaps most technical, process is the purification process for the production of food-grade fish collagen. However, acid and alkali extraction can produce chemical residues that can affect the biocompatibility and biological activity of collagen (Yang et al., 2026). High-purity collagen fractions are purified via gel filtration chromatography (e.g., Sephadex G100 or G-50), ultrafiltration and dialysis (Kumar et al., 2018; Sadhasivam et al., 2013). Electrodialysis has the potential to reduce the purification time and wastewater yield by 95%, preserve high extraction yields (67.3%), and ensure that the product is free of tetrodotoxin found in pufferfish species (Chen et al., 2019b). They are indispensable for filtering out small-molecule contaminants that would otherwise lead to skin irritation or systemic sensitization. Even fish waste collagen is by no means free of rigorous microbiological quality controls. Byproducts of raw fish are highly spoilable, and edible coatings of collagen have been developed to selectively inhibit the growth of proteolytic and lipolytic bacteria and microorganisms such as E. coli (Abdullah and Najim, 2025). For clinical and food applications, fish collagen should undergo stringent testing for sterility, resulting in a lack of bacteria, viruses and endotoxins (Huang et al., 2024). To the best of our knowledge, from safety studies of tilapia atelocollagen (Song et al., 2022; Huang et al., 2014), sterility tests for the material were negative, and there were no signs of cell toxicity, sensitization or systemic toxicity according to ISO standards. In addition to terminal sterilization, good manufacturing practices throughout the entire value chain contribute to high microbiological quality, contributing to the prevention of batch contamination and the production of consistent and safe products for human consumption (Dondero et al., 2025; Islam and Solval, 2025).

8 Comparison of the performance of the fish-collagen systems with that of commercial hydrocolloids and proteins

Compared with terrestrial animal and plant proteins, fish collagen systems are soluble, as they have greater gastrointestinal digestibility. One study of silver carp derivatives revealed that fish structuring agents dissolve in 5–6 min, which is at least two times faster than the dissolution time of the canonical animal collagen control (12 min) (Ivaniuta et al., 2021). Additionally, marine species have low interchain cross-link densities and are readily soluble. Specifically, the digestibility of protein in plant-based seafood analogs (pea proteins and pectin) was approximately 56.4%. The digestibility values of real seafood proteins and collagen from salmon skin are significantly greater (80.2% and 73%, respectively) than those of some white fish proteins (92%) (Wang et al., 2025; Zhang et al., 2023b). Fish collagen was also shown to have surface-active activities and to be more functional and safer than bovine gelatin and poultry proteins. Pool-based collagen from swim bladders of warm-water fish species (e.g., black carp, Mylopharyngodon piceus) exhibited much better emulsifying activity and foaming stability than chicken foot collagen and a better natural surfactant for stabilizing food emulsions (Wei et al., 2025). Compared with both bovine and porcine collagen, there is an important safety attribute to fish collagen in that there is no threat from zoonotic spread, as with bovine spongiform encephalopathy. Terrestrial protein is also a food additive that meets the dietary needs for religious requirements, which terrestrial protein may overlook (Islam and Solval, 2025; Wei et al., 2025). The low molecular weight (MW) of the extracted material and relatively high bioavailability offer nutritional benefits over mammalian higher protein contents (Rajabimashhadi et al., 2023; Venugopal, 2021). In general, it is less thermally stable and can induce weaker gels than bovine gelatin and simple hydrocolloids such as starch, alginate, and pectin. Fish collagen possesses relatively small proline and hydroxyproline contents, which play indispensable roles in stabilizing triple-helix scaffolds and producing reduced gelation and melting at relatively low temperatures (Derkach et al., 2020). Bovine gelatins tend to be stable at room temperature, as most bovine gelatins are still in their shape and structure at room temperature, with some tilapia gelatins retaining at least 14.9--15.0 °C in the temperature range (Marsal, 2019). In addition, carbohydrates (e.g., starch and alginate) have exceptional heat resistance (Binsi et al., 2007), in contrast with the polarized “melt-in-mouth” elasticity and thermoreversible effects of fish gelatin gels. Inhibition of this limitation will therefore need to be achieved, and fish collagen will be added to other commercially available proteins and hydrocolloids. Pectin can also enhance the overall physical stability of fish gelatin emulsions by promoting electrostatic and hydrophobic interactions between them and reducing phase separation (Huang et al., 2022; Zheng et al., 2025) in freeze–thaw reactions. On the other hand, the combination of tilapia gelatin and whey protein isolate can increase the gelling temperature of the mixture to 88.9 °C (Marsal, 2019) because of its more complex underlying matrices, which are significantly greater than those of either WPI or gelatin alone, thus reinforcing the gel system significantly. Furthermore, collagen (along with polysaccharides such as starch or modified cellulose) has also been shown to improve the water-holding capacity and decrease drip loss in processed meat and fish products to replace animal fats with small texture loss (Farooq et al., 2024; Gómez‐Guillén et al., 2011).

9 Current trends and future scope of collagen derived from fish processing waste

Considering the nexus between sustainability, bioactivity and an evolving consumer market in the commercialization of health products manufactured using marine biomaterials, fish waste-derived collagen has become an increasingly important bioresource as a functional food and nutraceutical. Research trends reveal a pattern of collagen extraction to develop value-added protein products with a physiological enhancement basis. In particular, fish collagen peptides are reported to be more widely used as supplements for drinking, soups and ready-to-drink preparations for skin health, as well as for antioxidant augmentation, muscle and musculoskeletal health for ingredients of food and beverages. As demonstrated in recent human and preclinical studies, skin hydration, elasticity, and wrinkling decrease, and several systemic effects (antioxidant effects and beneficial biochemical effects), as well as the beneficial effects of collagen ingestion, have been observed in the human diet (Huang et al., 2026; Wunnoo et al., 2025; Saito et al., 2026). Fish collagen is also utilized in food as a functional supplement for food quality enhancement and physiological response, such as increased protein enrichment and antioxidant bioaccessibility (instant soups), amelioration of postprandial glycemic control (hydrocolloids), and the availability of bioactive peptides with ACE-inhibitory and antioxidant properties (Babu et al., 2026; Dong et al., 2025; Abdullah et al., 2026). This trend closely illustrates something somewhat akin to the aspect of “biofunctionalization” and for the migration of fish collagen from an accessory structural protein ingredient to an active player in health and techno-functional consumption in food matrices. (Alcolea Ersinger et al., 2026; Wang et al., 2025) In contrast, the parallel advancements of extraction and processing in the past few years have concentrated on clean, rapid, and effective recovery from skins, bones, and other processing wastes, supporting circular economy models and decreasing the environmental costs of fishery byproducts. In addition to traditional nutraceutical applications, collagen from waterborne fish waste has applications in advanced high-tech, high-performance complex multifunctional systems for food preservation, controlled procurement and bionutritional constituents. Moreover, fish collagen has recently been shown (mechanical integrity, barrier function, antioxidant activity, and controlled release) to be useful for preserving food in biodegradable active films, collagen–chitosan packaging, peptide‐loaded microcapsules and composite hydrogels (Gonapinu wala et al., 2026; Zhou et al., 2026; Kong et al., 2026; Forid et al., 2026). Likewise, fish collagen‐based hydrogels and scaffolding materials for wound healing, tissue engineering and bone repair applications (for regenerative and therapeutic purposes) were also found to possess biocompatibility and tunable degradation profiles as well as pro-healing molecular responses (e.g., TGF‐β1 upregulation, MMP‐9 suppression, macrophage polarization and osteogenic stimulation) (Forid et al., 2026; Sun et al., 2026; Rokita et al., 2026; de Julian et al., 2026). The future prospects and directions would be, for example, standardized extraction and peptide profiling, clinically proven success, optimization of sensory and stability properties in the food system and integration of these features in a smart delivery apparatus. Scalable green technologies and residue valorization of many coproducts constitute a basis for more sustainable production and strong regulation of bioactive ingredients from fish. Collectively, fish waste-derived collagen can be a fundamental component of next-generation functional foods, nutraceuticals and bioactive hybrid compounds of broader scale, with potential use for sustainability, health promotion and circular bioeconomies (Huang et al., 2026; Alcolea Ersinger et al., 2026; Zhang et al., 2026).

10 Conclusion

Collagen obtained from fish waste has been shown to be an attractive, renewable bioresource for the development of novel functional foods, nutraceuticals and bioactive health products. The valorization of byproducts generated through fish processing, such as skin, scales, bones, fins, and swim bladders, addresses some of the greatest challenges of treatment related to fish waste in large-scale pollution emissions in seafood waste and, in turn, promotes the development of circular bioeconomies and zero waste industrial strategies. Improvements in extraction technology, enzymatic hydrolysis, nanoencapsulation, and bioactive formulation have contributed to the enhancement of the functional, dietary, and medicinal effects of fish collagen and collagen peptides. The data show that collagen derived from fish has good biocompatibility, high bioavailability, good digestibility and numerous biological activities, such as antioxidant, antihypertensive, anti-inflammatory, antiaging, osteogenic, wound healing, and skin protection effects. Moreover, its effective coupling to beverages, soups, nutraceuticals, edible films, active packaging systems, hydrogels and delivery matrices illustrates the versatility of this material as both a functional and a biomaterial. Among the advantages of fish collagen over mammalian collagen are a lower risk of zoonotic disease transmission with consumer acceptance, better adoption among groups pursuing religion and culture, and greater sustainability. However, several areas have been fully investigated: thermal stability, sensory characterization, extraction protocol standardization, mass processing, and long-term clinical validation of these findings. In the long term, future studies need to test green extraction technologies, peptide structure–function relationships, delivery system improvements, omics-based bioactivity assays and human tests for industry and regulation acceptance. However, fish waste collagen is a very interesting novel and innovative biomaterial in marine life that catalyzes the conversion of seafood waste byproducts into functional and nutraceutical products and has simultaneous applications in human health, sustainable food systems and environmental protection.

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Footnotes

Edited by: Elavarasan Krishnamoorthy, Central Institute of Fisheries Technology (ICAR), India

Reviewed by: Chen Chen, Zhejiang University, China

Ikhlas Laasri, University Central de Cataluyna-University of Vic, Spain