Fish Waste: From Problem to Valuable Resource

Valorization of fishery industry waste: Chitosan extraction and its application in the industry

Waste from the fishing industry is disposed of in soils and oceans, causing environmental damage. However, it is also a source of valuable compounds such as chitin. Although chitin is the second most abundant polymer in nature, its use in industry is limited due to the lack of standardized and scalable extraction methods and its poor solubility. The deacetylation process increases its potential applications by enabling the recovery of chitosan, which is soluble in dilute acidic solutions. Chitosan is a polymer of great importance due to its biocompatible and bioactive properties, which include antimicrobial and antioxidant capabilities. Chitin extraction and its deacetylation to obtain chitosan are typically performed using chemical processes that involve large amounts of strongly acidic and alkaline solutions. To reduce the environmental impact of this process, extraction methods based on biotechnological tools, such as fermentation and chitin deacetylase, as well as emerging technologies, have been proposed. These extraction methods have demonstrated the potential to reduce or even avoid using strong solvents and shorten extraction time, thereby reducing costs. Nevertheless, it is important to address existing gaps in this area, such as the requirements for large-scale implementation and the determination of the stoichiometric ratios for each process. This review highlights the use of biotechnological tools and emerging technologies for chitin extraction and chitosan production. These approaches truly minimize environmental impact, reduce the use of strong solvents, and shorten extraction time. They are a reliable alternative to fishery waste valorization, lowering costs; however, addressing the critical gaps for their large-scale implementation remains challenging.

Valorization of fish processing by-products for protein hydrolysate recovery: Opportunities, challenges and regulatory issues

Protein-rich fish processing by-products, often called rest raw materials (RRM), account for approximately 60% of the total fish biomass. However, a considerable amount of these RRM is utilized for low-value products such as fish meal and silage. A promising and valuable approach for maximizing the utilization of RRM involves the extraction of bioactive fish protein hydrolysate (FPH). This review assesses and compares different hydrolyzation methods to produce FPH. Furthermore, the review highlights the purification strategy, nutritional compositions, and bioactive properties of FPH. Finally, it concludes by outlining the application of FPH in food products together with various safety and regulatory issues related to the commercialization of FPH as a protein ingredient in food. This review paves the way for future applications by highlighting efficient biotechnological methods for valorizing RRM into FPH and addressing safety concerns, enabling the widespread utilization of FPH as a valuable and sustainable source of protein.

Valorization of seafood waste: a review of life cycle assessment studies in biorefinery applications

The escalating challenges posed by seafood waste generated by the fishing and aquaculture industries underscore the urgent need for innovative solutions that promote both environmental conservation and economic viability within the seafood sector. Seafood waste biorefinery emerges as a promising solution, offering the potential to transform waste materials into valuable products. However, it is essential to recognize that seafood waste biorefinery operations also entail environmental impacts that warrant careful consideration. Environmental assessment tools like Life Cycle Assessment (LCA) provide a valuable framework for assessing these impacts comprehensively. This review critically examines LCA studies in seafood waste biorefinery, focusing on key concepts, emerging technologies, and potential product avenues. Despite the growing body of research in this area, direct comparisons between published studies prove challenging due to discrepancies in feedstocks, processing techniques, value-added products, and LCA methodologies. Nevertheless, the findings consistently demonstrate significant reductions in environmental impacts achieved through seafood waste biorefinery processes. The selection of technologies significantly influences both product quality and sustainability measures. High energy consumption, including diesel fuel consumption in fishing vessels and electricity consumption in processing steps, should be carefully considered and reduced to mitigate associated environmental impacts. In conclusion, while seafood waste biorefinery processes hold significant promise for providing environmental and economic benefits, substantial challenges remain. This review provides invaluable insights for researchers, policymakers, and stakeholders, emphasizing the importance of continuous interdisciplinary collaboration and methodological standardization to advance sustainable waste management practices in the seafood industry.

A Review on Fish Skin-Derived Gelatin: Elucidating the Gelatin Peptides-Preparation, Bioactivity, Mechanistic Insights, and Strategies for Stability Improvement

Fish skin-derived gelatin has garnered significant attention recently due to its abundant availability and promising bioactive properties. This comprehensive review elucidates various intricacies concerning fish skin-derived gelatin peptides, including their preparation techniques, bioactive profiles, underlying mechanisms, and methods for stability enhancement. The review investigates diverse extraction methods and processing approaches for acquiring gelatin peptides from fish skin, emphasizing their impact on the peptide composition and functional characteristics. Furthermore, the review examines the manifold bioactivities demonstrated by fish skin-derived gelatin peptides, encompassing antioxidant, antimicrobial, anti-inflammatory, and anticancer properties, elucidating their potential roles in functional food products, pharmaceuticals, and nutraceuticals. Further, mechanistic insights into the functioning of gelatin peptides are explored, shedding light on their interactions with biological targets and pathways. Additionally, strategies aimed at improving the stability of gelatin peptides, such as encapsulation, modification, and integration into delivery systems, are discussed to extend the shelf life and preserve the bioactivity. Overall, this comprehensive review offers valuable insights into using fish skin-derived gelatin peptides as functional ingredients, providing perspectives for future research endeavors and industrial applications within food science, health, and biotechnology.

Developing fish oil emulsion gel enriched with Lentinula edodes single cell protein and its effect on controlling the growth of Acinetobacter baumannii

In this study, the characterization of fish oil (FO) emulsion gel (EGEL) containing single cell protein (SCP) produced from Lentinula edodes (L. edodes) and its potential inhibition against Acinetobacter baumannii (A. baumannii) were investigated. Oil extracted from the fish liver was emulsified with tween 80 and water, and then gelled using gelatin with the assistance of an ultrasonic homogenizer. The characteristics and surface analysis of SCP-EGEL were examined using FTIR (Fourier-transform infrared spectroscopy) and SEM (Scanning electron microscope). The particle size distribution and zeta potential of SCP-EGEL were measured using a Malvern Zetasizer. When SCP-EGEL was applied to the surface of the medium inoculated with A. baumannii, the inhibition zone (IZ) was 8.2 mm. An expansion of the IZ was observed (10.2 mm) when SCP-EGEL was applied to a fish skin (FS) surface prepared in the shape of a 6-mm diameter disc. In the SEM images, when SCP was added to lipo gel, the gel structure appeared flattened or swollen in some areas. The appearance of SCP cells being covered with gel gave the impression that they have a secondary wall. Therefore, the resulting complex can potentially be used as an additive in animal and human nutrition, in functional food coatings to suppress A. baumannii, and in fish feed to enrich it with protein.

Assessment of dietary Selenium and its role in Mercury fate in cultured fish rainbow trout with two sustainable aquafeeds

This study enhances the current limited understanding of the interaction between mercury (Hg) and selenium (Se) species in fish. Rainbow trout (Oncorhynchus mykiss), a model aquaculture fish, was exposed to Hg and Se species through controlled dietary conditions. Over a 6-month feeding trial, the impact of dietary Se on Hg bioaccumulation in fish, including flesh, brain, and liver, was tracked. Twelve dietary conditions were tested, including plant-based diets (0.25 µgSe g-1) and tuna byproduct diets (0.25 µgHg g-1, 8.0 µgSe g-1) enriched with methylmercury and/or Se as selenite or selenomethionine. The tuna byproduct diet resulted in lower Hg levels than the plant-based diets, with muscle Hg content below the European Commission's safe threshold. This study highlights the significant impact of specific Se compounds in the diet, particularly from tuna-based aquafeed, on Hg bioaccumulation. These promising results provide a strong recommendation for future use of fisheries byproducts in sustainable aquafeeds.

The Revalorization of Fishery By-Products: Types, Bioactive Compounds, and Food Applications

Recently, fish consumption has been increasing; subsequently, the number of by-products has also increased. However, generated residues are frequently discarded, and an appropriate management is necessary to properly use all fish by-products. Fishery by-products are well known for their content of bioactive compounds, such as unsaturated fatty acids, amino acids, minerals, peptides, enzymes, gelatin, collagen, and chitin. Several studies have reported that fishery by-products could provide significant properties, including antioxidant, antihypertensive, antimicrobial, anti-inflammatory, and antiobesity. Consequently, fish discards are of considerable interest to different industrial sectors, including food, nutraceuticals, medical, and pharmacology. In the food industry, the interest in using fishery by-products is focused on hydrolysates as food additives, collagen and gelatin as protein sources, chitin and chitosan to form edible films to protect food during storage, and oils as a source of Omega-3 and useful as antioxidants. Although different studies reported good results with the use of these by-products, identifying new applications in the food sector, as well as industrial applications, remains necessary.

Circular bioeconomy in action: Upscaling cutlassfish waste for eco-friendly recombinant protein production

The fish processing industry generates a significant amount of waste, and the recycling of this waste is an issue of global concern. We sought to utilize the heads of cutlassfish (Trichiurus lepturus), which are typically discarded during processing, to produce peptone, which is an important source of amino acids for microbial growth and recombinant protein production. Cutlassfish head muscle (CHM) were isolated, and the optimal protease and reaction conditions for peptone production were determined. The resulting peptone contained 12.22 % total nitrogen and 3.19 % amino nitrogen, with an average molecular weight of 609 Da, indicating efficient hydrolysis of CHM. Growth assays using Escherichia coli have shown that cutlassfish head peptone (CP) supports similar or superior growth compared to other commercial peptones. In addition, when recombinant chitosanase from Bacillus subtilis and human superoxide dismutase were produced in E. coli, CP gave the highest expression levels among six commercial peptones tested. In addition, the expression levels of chitosanase and superoxide dismutase were 20 % and 32 % higher, respectively, in CP medium compared to the commonly used Luria-Bertani (LB) medium. This study demonstrates the potential of using cuttlassfish waste in the production of microbial media, thereby adding significant value to fish waste. The results contribute to sustainable waste management practices and open avenues for innovative uses of fish processing by-products in biotechnological applications.

From 7-dehydrocholesterol to vitamin D3: Optimization of UV conversion procedures toward the valorization of fish waste matrices

Vitamin D, a fat-soluble steroid, has increasingly taken a central role due to its crucial role in human health. It is estimated that about 40% of worldwide population are vitamin D deficient. The fish industry produces significant quantities of waste daily, with consequent high environmental impact. The aim of this work is to place a first brick for the fish waste reuse as a source of vitamin D3 extracts to be used for nutraceutical purposes. For this purpose, an UV conversion method for transforming the 7-dehydrocholesterol, highly present in fish, in vitamin D3 has been optimized. The UV wavelength, exposure time, temperature, stirring, and UV intensity were optimized using a surface response design tool. The optimized treatment was applied to five fish species with different fat percentages and the results were very promising reaching vitamin D3 levels >10 times higher than the pre-treatment ones.

Catalytic pyrolysis of fish waste oil using ZSM-5 catalyst for the production of renewable biofuel

This present study enlightens the eco-friendly green synthesis of ZSM-5 from natural clay montmorillonite, and its proper incorporation with 'Ni'. Nickle (Ni) was wet impregnated onto HZSM-5 and the resulting catalyst was characterized by various techniques including XRD, BET, N2 Sorption Studies, TPD, SEM and TEM techniques. The SEM images revealed the uniform distribution of Ni over HZSM-5 zeolite catalyst and the XRD results indicated the undistorted crystalline structure of HZSM-5 even after impregnation of Ni. The latter part of the work concentrates on the strength of the catalyst in cracking oil derived from discarded fish parts. Discarded fish waste was pyrolyzed to obtain the fish oil, which was then used for cracking studies. The fish oil was efficiently converted (99% conversion) by Ni/ZSM5 (50 wt %) and yielded 70% liquid fractions, which formed gasoline (78.6%), kerosene (12.3%) and diesel (9.1%). The research is a complete parcel to examine the working potential of the produced biofuel in pre-existing engines. The quality of gasoline fraction was tested according to ASTM standards, which showed that the heating value was slightly lower compared to fossil gasoline. The torque and brake fuel consumption were also examined and it indicated that the fish oil derived gasoline fuel may need to be mixed with the commercial gasoline to optimize its performance.

Development of Biodegradable Bioplastics with Sericin and Gelatin from Silk Cocoons and Fish Waste

The bioplastics sector promotes environmentally friendly means of cutting down on the usage of fossil fuels, plastic waste, and environmental pollution. Plastic contamination has detrimental effects on both ecological systems and the global food supply. The approach we present here to resolve this issue involves the integration of sericin and gelatin, obtained from cocoon and fish waste, respectively, with nano-reinforced cellulose crystals, to develop a biodegradable and compostable plastic material. The use of cocoon and fish wastes for the extraction of sericin and gelatin presents an environmentally beneficial approach since it contributes to waste reduction. The sericin level found in silk cocoon waste was determined to be 28.08%, and the gelatin amount in fish waste was measured to be 58.25%. The inclusion of sericin and gelatin in bioplastics was accompanied by the incorporation of glycerol, vinegar, starch, sodium hydroxide, and other coloring agents. Fourier transform infrared (FTIR) examination of bioplastics revealed the presence of functional groups that corresponded to the sericin and gelatin components. The tensile strength of the bioplastic material was measured to be 27.64 MPa/psi, while its thickness varied between 0.072 and 0.316 mm. The results of burial experiments indicated that the bioplastic material had a degradation rate of 85% after 14 days. The invention exhibits potential as a viable alternative for packaging, containment, and disposable plastic materials. The use of this sustainable approach is recommended for the extraction of sericin and gelatin from silk cocoons and fish waste, with the intention of using them as raw materials for bioplastic production.

Postprandial plasma amino acid and appetite responses with ingestion of a novel salmon-derived protein peptide in healthy young adults

This study assessed postprandial plasma aminoacidemia, glycemia, insulinemia and appetite responses to ingestion of a novel salmon-derived protein peptide (Salmon PP) compared with milk protein isolate (Milk PI). In a randomised, participant-blind crossover design, eleven healthy adults (M = 5, F = 6; mean ± sd age: 22 ± 3 years; BMI: 24 ± 3 kg/m2) ingested 0·3 g/kg/body mass of Salmon PP or Milk PI. Arterialised blood samples were collected whilst fasted and over a 240-min postprandial period. Appetite sensations were measured via visual analogue scales. An ad libitum buffet-style test meal was administered after each trial. The incremental AUC (iAUC) plasma essential amino acid (EAA) response was similar between Salmon PP and Milk PI. The iAUC plasma leucine response was significantly greater following Milk PI ingestion (P < 0·001), whereas temporal and iAUC plasma total amino acid (P = 0·001), non-essential amino acid (P = 0·002), glycine (P = 0·0025) and hydroxyproline (P < 0·001) responses were greater following Salmon PP ingestion. Plasma insulin increased similarly above post-absorptive values following Salmon PP and Milk PI ingestion, whilst plasma glucose was largely unaltered. Indices of appetite were similarly altered following Salmon PP and Milk PI ingestion, and total energy and macronutrient intake during the ad libitum meal was similar between Salmon PP and Milk PI. The postprandial plasma EAA, glycine, proline and hydroxyproline response to Salmon PP ingestion suggest this novel protein source could support muscle and possibly connective tissue adaptive remodelling, which warrants further investigation, particularly as the plasma leucine response to Salmon PP ingestion was inferior to Milk PI.

Status of Fishery Discards and By-Products in Greece and Potential Valorization Scenarios towards a National Exploitation Master Plan

The valorization of aquaculture/fishery processing by-products, as well as unavoidable/unwanted catches and discards in Greece, is currently an underutilized activity despite the fact that there are several best practices in Northern Europe and overseas. One of the main challenges is to determine whether the available quantities for processing are sufficient to warrant the valorization of discards and fish side streams. This is the first attempt to systematically record and analyze the available quantities of fish by-products and discards in Greece spatially and temporally in an effort to create a national exploitation Master Plan for the valorization of this unavoidable and unwanted biomass. A thorough survey conducted within the VIOAXIOPIO project unveiled a substantial biomass of around 19,000 tonnes annually that could be harnessed for valorization. Furthermore, the production of various High-Added-Value Biomolecules (HAVBs) was investigated and experimental trials were conducted to assess the potential yields, with the collected data used to formulate four valorization scenarios.

Chitosan and Chitooligosaccharides: Antifungal Potential and Structural Insights

Chitosan is a cationic polysaccharide derived from chitin deacetylation. This polysaccharide and its oligosaccharides have many biological activities and can be used in several fields due to their favorable characteristics, such as biodegradability, biocompatibility, and nontoxicity. This review aims to explore the antifungal potential of chitosan and chitooligosaccharides along with the conditions used for the activity and mechanisms of action they use to kill fungal cells. The sources, chemical properties, and applications of chitosan and chitooligosaccharides are discussed in this review. It also addresses the threat fungi pose to human health and crop production and how these saccharides have proven to be effective against these microorganisms. The cellular processes triggered by chitosan and chitooligosaccharides in fungal cells, and prospects for their use as potential antifungal agents are also examined.

New Insight into Utilization of Fish By-Product Proteins and Their Skin Health Promoting Effects

In regions reliant on fisheries for livelihoods, a significant number of fish by-products are generated annually due to processing. These discarded parts contain valuable biological resources, such as proteins, fish oils, and trace elements, thus holding enormous potential for reutilization. In recent years, fish by-product proteins have been widely utilized in skincare products due to their rich collagen content, biosafety, and biocompatibility. This review summarizes the research into and applications of fish by-product proteins in skin health, including alleviating oxidative stress and skin inflammation, reducing DNA damage, mitigating melanin production, improving skin hydration, slowing skin matrix degradation, and promoting synthesis. Additionally, the possibility of improving skin health by improving the abundance of gut microbiota is also discussed. This review underscores the importance of fish by-product proteins in the fisheries, food processing, cosmetics, and biomedical industries.

Protein hydrolysate and oil from fish waste reveal potential as dog food ingredients

The increased fish consumption by the growing human population in the world translates into an increase in fish waste. The reintroduction of these fish by-products into food and feed chains presents economic benefits and contributes to counteracting their negative environmental impact. Under this context, the present study aimed to evaluate the effects of the dietary inclusion of fish hydrolysate and oil obtained from fish waste (experimental diet) in substitution of shrimp hydrolysate and salmon oil (control diet) mainly imported from third countries on palatability, apparent total tract digestibility, fecal characteristics and metabolites, blood fatty acid profile, flatulence, and coat quality of adult dogs. A two-bowl test was performed to evaluate palatability by the pairwise comparison between the two diets. A feeding trial was conducted according to a crossover design with two diets (control and experimental diets), six adult Beagle dogs per diet, and two periods of 6 weeks each. The replacement of shrimp hydrolysate and salmon oil with fish hydrolysate and oil did not affect the first diet approach and taste, as well as the intake ratio. Generally, the digestibility of dry matter, nutrients, and energy was not affected by diet, but the intake of digestible crude protein (CP) and ether extract was higher, respectively, with the control and the experimental diet. The higher intake of eicosapentaenoic acid and docosahexaenoic acid with the experimental diet was reflected in a higher content of these long-chain polyunsaturated fatty acids and the omega-3 index of red blood cells, but it did not affect coat quality. The significantly higher intake of digestible CP with the control diet might have contributed to the higher fecal ammonia-N and valerate concentrations. Daily fecal output and characteristics were similar between diets. Overall, results suggest that fish hydrolysate and oil from the agrifood industry might constitute sustainable functional ingredients for dog feeding while adding value for wild fisheries, aquaculture, and fish farming under a circular economy approach and reducing dependence on imports from third countries with a high carbon footprint.

Microbes as a tool for the bioremediation of fish waste from the environment and the production of value-added compounds: a review

Fish are the most edible protein source worldwide and generate several remnants such as scales, viscera, head, bone, and skin. Fish wastes are not disposed of properly, which adversely affects the environment, especially the water bodies where fish processing industries dispose of their waste. Fish waste mainly contains nitrogen, oil, fat, salts, heavy metals, and organic compounds, which increase the biological oxygen demand and chemical oxygen demand. Fish waste can degrade in various ways, such as physicochemical or by enzymatic action, but using microbes is an environmentally friendly approach that can provide valuable compounds such as products such as collagen, chitin, minerals, and fish protein concentrates. This review is designed to focus on the suitability of microbes as tools for fish waste degradation and the production of certain associated. This study also provides insight into the production of other compounds such as protease, chitinase, and chitin applicability of these products. After processing, fish waste as a microbial growth media for enzyme production since microorganisms synthesize enzymes such as proteases, protein hydrolysates, lipids, and chitinase, which have broader applications in the pharmaceutical, cosmetic, biomedical material, and food processing industries.

Seabream Quality Monitoring Throughout the Supply Chain Using a Portable Multispectral Imaging Device

Monitoring food quality throughout the supply chain in a rapid and cost-effective way allows on-time decision-making, reducing food waste, and increasing sustainability. A portable multispectral imaging sensor was used for the rapid prediction of microbiological quality of fish fillets. Seabream fillets, packaged either in aerobic or vacuum conditions, were collected from both aquaculture and retail stores, while images were also acquired both from the skin and the flesh side of the fish fillets. In parallel to image acquisition, the microbial quality was also estimated for each fish fillet. The data were used for the training of predictive artificial neural network (ANN) models for the estimation of total aerobic counts (TACs). Models were built separately for fish parts (i.e., skin, flesh) and packaging conditions and were validated using two approaches (i.e., validation with data partitioning and external validation using samples from retail stores). The performance of the ANN models for the validation set with data partitioning was similar for the data collected from the flesh (RMSE = 0.402-0.547) and the skin side (RMSE = 0.500-0.533) of the fish fillets. Similar performance also was obtained from validation of the models of the different packaging conditions (i.e., aerobic, vacuum). The prediction capability of the models combining both air and vacuum packaged samples (RMSE = 0.531) was slightly lower compared to the models trained and validated per packaging condition, individually (RMSE = 0.510, 0.516 in air and vacuum, respectively). The models tested with unknown samples (i.e., fish fillets from retail stores-external validation) showed poorer performance (RMSE = 1.061-1.414) compared to the models validated with data partitioning (RMSE = 0.402-0.547). Multispectral imaging sensor appeared to be efficient for the rapid assessment of the microbiological quality of fish fillets for all the different cases evaluated. Hence, these outcomes could be beneficial not only for the industry and food operators but also for the authorities and consumers.

Optimization of methane production from solid tuna waste: Thermal pretreatment and co-digestion

Fish canning industries generate large amounts of solid waste during their processing operations, creating a significant environmental challenge. Nonetheless, this waste can be efficiently and sustainably treated through anaerobic digestion. In this study, the potential of biogas production from anaerobic digestion of thermally pretreated and co-digested solid tuna waste was investigated. The thermal pretreatment of raw fish viscera resulted in a 50 % increase in methane yield, with a production of 0.27 g COD-CH4/g COD added. However, this pretreatment did not lead to a significant increase in biogas production for cooked tuna viscera. When non-thermally pretreated raw viscera was tested, a large accumulation of volatile fatty acids and long chain fatty acids was observed, with levels reaching 21 and 6 g COD/L, respectively. On the other hand, anaerobic co-digestion of cooked tuna viscera with fat waste significantly enhanced methane production, achieving 0.87 g COD-CH4/g COD added. In contrast, co-digestion of cooked tuna viscera with dairy waste and sewage sludge resulted in notably lower yields of 0.36 and 0.46 g COD-CH4/g COD added, respectively. These results may be related to the C/N ratio, which was found to be within the optimal range for anaerobic digestion only in the tuna and fat waste co-digestion assay.

High oxidative stability of a complex fish liver oil nano-capsules in response to long-term storage, and to hyperthermal and sunlight exposure

BACKGROUND

In this study, a biocompatible nano-carrying platform using chitosan (ChI) and chondroitin sulfate (ChS) was developed for the encapsulation of cobia liver oil (CBLO) to prevent its oxidation and improve its absorption. An ionic gelation method was applied to encapsulate CBLO with different weight ratios (from 1.0 to 1.5) to obtain ChS-ChI nano-capsules (ChS-ChI@CBLO NCs).

RESULTS

Morphological observations of the nano-capsules revealed a spherical shape and diameter around 267-381 nm. The maximum loading capacity (LC) and encapsulation efficiency (EE) for ChS-ChI@CBLO NCs estimated by thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) analysis were 25.7% and 56.2%, respectively. The structural stability of ChS-ChI@CBLO NCs was confirmed through differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis; moreover DSC also further confirmed the oxidative stability of ChS-ChI@CBLO NCs. Fourier-transform infrared (FTIR) spectra confirmed the excellent stability of ChS-ChI@CBLO NCs against high temperature and sunlight exposure. Biocompatibility analysis also verified the non-toxicity of ChS-ChI@CBLO NCs, further indicating safety and potential application in complex-nutritional supplements.

CONCLUSION

Nano-degree of ChS-ChI@CBLO NCs has a loading capacity and encapsulation efficiency of around 16.5 ~ 25.7% and 33.4 ~ 56.2%, respectively, for encapsulation of CBLO. Characterization results also indicate that ChS-ChI@CBLO NCs display high oxidative stability against long-term, hyperthermal, and sunlight exposure. Bioassay results confirm that the ChS-ChI@CBLO NCs are safe and non-toxic. This study demonstrates that nano-capsules are also beneficial in preventing sensitive compounds from metamorphosis, and are non-toxic. These materials are suitable for use in the food and pharmaceutical industries. © 2023 Society of Chemical Industry.

Evaluation of a hydroxyapatite-crosslinked fish gelatin membranes

Background/purpose

Porcine collagen is widely used in regenerative therapies to generate membranes for bone augmentation. However, porcine or bovine gelatin or collagen is often not appropriate for patients with creed and religious beliefs or for allergic reasons. In this study, we evaluated the potential of fish gelatin to generate membranes.

Materials and methods

Fish gelatin and hydroxyapatite (HAp) were used at three different ratios (2:0, 2:1, 2:1.5, and 2:2) to prepare gelatin-hydroxyapatite (G-HAp) membranes via freeze-drying and heat-crosslinking. The surface morphology and cell attachment of G-HAp membranes were observed using scanning electron microscopy and confocal laser microscopy. G-HAp membrane was placed at the bottom of a well plate, and MC3T3-E1 cells were seeded on it. Cell viability and cytotoxicity were tested after 1 and 3 days of culture. Alkaline phosphatase (ALP) and alizarin red staining was performed at 10 and 21 days, respectively.

Results

Viability of cells on G-HAp membrane with the gelatin:HAp ratio of 2:1.5 was significantly higher than that on membranes with other gelatin:HAp ratios. ALP and alizarin red staining showed that ALP-positive areas and calcium deposition were the highest on G-HAp membrane with the gelatin:HAp ratio of 2:1. These membranes showed negligible cytotoxicity.

Conclusion

Fish-derived G-HAp membranes have the potential to promote osteogenic differentiation of MC3T3-E1 cells with negligible cytotoxicity.

Upcycling of seafood side streams for circularity

The upcycling of seafood side streams emerges as a crucial facet in the quest for circularity within the food industry, surpassing other food sources in its significance. Seafood side stream plays an indispensable role in global food security and human nutrition. Nevertheless, losses ensue throughout the seafood supply chain, resulting in substantial waste generation. These underutilized seafood by-products contain valuable resources like edible proteins and nitrogenous compounds. Projections indicate that fishery products' utilization for human consumption will soar to 204 MT by 2030. Yet, the industry annually generates millions of tonnes of waste, predominantly from crab, shrimp, and lobster shells, leading to environmental impacts due to COD and BOD issues. A five-tier circular economic model offers a framework to manage seafood side-streams efficiently, with applications spanning pharmaceuticals, food production, animal feed, fertilizers, and energy fuel, thereby maximizing their potential and reducing waste in line with sustainability goals.

Marine Animal Co-Products-How Improving Their Use as Rich Sources of Health-Promoting Lipids Can Foster Sustainability

Marine lipids are recognized for their-health promoting features, mainly for being the primary sources of omega-3 fatty acids, and are therefore critical for human nutrition in an age when the global supply for these nutrients is experiencing an unprecedent pressure due to an ever-increasing demand. The seafood industry originates a considerable yield of co-products worldwide that, while already explored for other purposes, remain mostly undervalued as sustainable sources of healthy lipids, often being explored for low-value oil production. These co-products are especially appealing as lipid sources since, besides the well-known nutritional upside of marine animal fat, which is particularly rich in omega-3 polyunsaturated fatty acids, they also have interesting bioactive properties, which may garner them further interest, not only as food, but also for other high-end applications. Besides the added value that these co-products may represent as valuable lipid sources, there is also the obvious ecological upside of reducing seafood industry waste. In this sense, repurposing these bioresources will contribute to a more sustainable use of marine animal food, reducing the strain on already heavily depleted seafood stocks. Therefore, untapping the potential of marine animal co-products as valuable lipid sources aligns with both health and environmental goals by guaranteeing additional sources of healthy lipids and promoting more eco-conscious practices.

Effect of seasonal variation and farming systems on the properties of Nile tilapia gelatin extracted from scales

Although fish gelatin has become a research hotspot in recent years, researchers and manufacturers are still looking for high-quality sources of fish galatin to meet the commercial demand for safer gelatin.became This study aimed to evaluate the impact of seasonal variation and farming systems on the properties of gelatin extracted from Nile tilapia scales. Gelatin extracted from farmed tilapia had lowest impurities, higher clarity as well as desirable color characteristics (L* = 65.95 and a* = -0.33). The protein and fat composition of Wild (91.00 ± 0.00c) and 1.94 ± 0.05a respectively were higher than farmed gelatin of protein (91.00 ± 0.00c) and fat (0.84 ± 0.08b) but gelatin from the farmed type were clearer (98.30 ± 0.28a) than wild type (94.60 ± 0.28b). In addition, the XRD analysis confirmed its amorphous structure (2θ = 11°, 21°. 29°, and 31°). The gelatin extracted from wild tilapia showed an average yield of 1.98 % and good physicochemical and functional properties. Furthermore, FTIR indicated a strong bond positioned in the amide I region (1650.88 cm-1) of the wild tilapia gelatin. Partial Least Square (PLS) confirmed that viscosity is positively correlated with melting temperature upon a unit change in gelatin yield. This work highlights the significance of farming systems and seasonal variation in extraction conditions and great parameter to comprehensively navigate the functional, biochemical, and physical properties of Nile tilapia gelatin for broadening both food and non-food industrial appliactions.

Assessment of Tilapia Skin Collagen for Biomedical Research Applications in Comparison with Mammalian Collagen

Collagen is an important material for biomedical research, but using mammalian tissue-derived collagen carries the risk of zoonotic disease transmission. Marine organisms, such as farmed tilapia, have emerged as a safe alternative source of collagen for biomedical research. However, the tilapia collagen products for biomedical research are rare, and their biological functions remain largely unexamined. In this study, we characterized a commercial tilapia skin collagen using SDS-PAGE and fibril formation assays and evaluated its effects on skin fibroblast adhesion, proliferation, and migration, comparing it with commercial collagen from rat tails, porcine skin, and bovine skin. The results showed that tilapia skin collagen is a type I collagen, similar to rat tail collagen, and has a faster fibril formation rate and better-promoting effects on cell migration than porcine and bovine skin collagen. We also confirmed its application in a 3D culture for kidney cells' spherical cyst formation, fibroblast-induced gel contraction, and tumor spheroid interfacial invasion. Furthermore, we demonstrated that the freeze-dried tilapia skin collagen scaffold improved wound closure in a mouse excisional wound model, similar to commercial porcine or bovine collagen wound dressings. In conclusion, tilapia skin collagen is an ideal biomaterial for biomedical research.

Sustainable Sources of Raw Materials for Additive Manufacturing of Bone-Substituting Biomaterials

The need for sustainable development has never been more urgent, as the world continues to struggle with environmental challenges, such as climate change, pollution, and dwindling natural resources. The use of renewable and recycled waste materials as a source of raw materials for biomaterials and tissue engineering is a promising avenue for sustainable development. Although tissue engineering has rapidly developed, the challenges associated with fulfilling the increasing demand for bone substitutes and implants remain unresolved, particularly as the global population ages. This review provides an overview of waste materials, such as eggshells, seashells, fish residues, and agricultural biomass, that can be transformed into biomaterials for bone tissue engineering. While the development of recycled metals is in its early stages, the use of probiotics and renewable polymers to improve the biofunctionalities of bone implants is highlighted. Despite the advances of additive manufacturing (AM), studies on AM waste-derived bone-substitutes are limited. It is foreseeable that AM technologies can provide a more sustainable alternative to manufacturing biomaterials and implants. The preliminary results of eggshell and seashell-derived calcium phosphate and rice husk ash-derived silica can likely pave the way for more advanced applications of AM waste-derived biomaterials for sustainably addressing several unmet clinical applications.

Pepsin Hydrolysate from Surimi Industry-Related Olive Flounder Head Byproducts Attenuates LPS-Induced Inflammation and Oxidative Stress in RAW 264.7 Macrophages and In Vivo Zebrafish Model

Fish head byproducts derived from surimi processing contribute about 15% of the total body weight, which are beneficial to health because they contain essential nutrients. In this study, olive flounder (OF) was the target species in order to maximize the byproduct utilization. In RAW 264.7 macrophages, the seven hydrolysates from OF head byproducts were examined for their inhibitory potential against inflammation and the oxidative stress induced by lipopolysaccharides (LPS). The pepsin hydrolysate (OFH-PH) demonstrated strong anti-inflammatory activity via the down-regulation of NO production, with an IC50 value of 299.82 ± 4.18 µg/mL. We evaluated the inhibitory potential of pro-inflammatory cytokines and PGE2 to confirm these findings. Additionally, iNOS and COX-2 protein expressions were confirmed using western blotting. Furthermore, the results from the in vivo zebrafish model demonstrated that OFH-PH decreased the LPS-elevated heart rate, NO production, cell death, and intracellular ROS level, while increasing the survival percentage. Hence, the obtained results of this study serve as a platform for future research and provide insight into the mediation of inflammatory disorders. These results suggest that OFH-PH has the potential to be utilized as a nutraceutical and functional food ingredient.

Green Chemistry to Valorize Seafood Side Streams: An Ecofriendly Roadmap toward Sustainability

A major challenge facing sustainable seafood production is the voluminous amounts of nutrient-rich seafood side streams consisting of by-catch, processing discards, and process effluents. There is a lack of a comprehensive model for optimal valorization of the side streams. Upcoming green chemistry-based processing has the potential to recover diverse valuable compounds from seafood side streams in an ecofriendly manner. Microbial and enzymatic bioconversions form major green processes capable of releasing biomolecules from seafood matrices under mild conditions. Novel green solvents, because of their low toxicity and recyclable nature, can extract bioactive compounds. Nonthermal technologies such as ultrasound, supercritical fluid, and membrane filtration can complement green extractions. The extracted proteins, peptides, polyunsaturated fatty acids, chitin, chitosan, and others function as nutraceuticals, food supplements, additives, etc. Green processing can address environmental, economic, and technological challenges of valorization of seafood side streams, thereby supporting sustainable seafood production. Green processing can also encourage bioenergy production. Multiple green processes, integrated in a marine biorefinery, can optimize valorization on a zero-waste trade-off, for a circular blue economy. A green chemistry-based valorization framework has the potential to meet the Sustainable Development Goals (SDGs) of the United Nations.

Green Extraction and Preliminary Biological Activity of Hydrolyzed Collagen Peptides (HCPs) Obtained from Whole Undersized Unwanted Catches (Mugil cephalus L.)

Considering the global increase in fish consumption, the growing side-streams coming from the fish supply chain (e.g., skin, fins, tail, heads…), also including undersized or "unwanted catches", have been recently proposed as source of high-value bioactive compounds (e.g., peptides and fatty acids). In this case study, hydrolyzed collagen peptides (HCPs) were extracted from different parts of Mugil cephalus L. using environmentally friendly techniques such as ultrasounds and enzymatic treatments. Both a mixed biomass derived from the skin, fins, and tail, and a whole fish, were considered as starting biomass, simulating the unsorted processing side-streams and an undersized/unwanted catch, respectively. The extracted HCPs were purified in fractions (<3 KDa and >3 KDa) whose yields (about 5% and 0.04-0.3%, respectively) demonstrated the efficiency of the hydrolysis process. The extraction protocol proposed allowed us to also isolate the intermediate products, namely the lipids (about 8-10%) and the non-collagenous proteins (NCs, 16-23%), whose exploitation could be considered. Each sample was characterized using Sircol, UltraViolet-Spectra, and hydroxyproline assay, and the viability of their collagen fractions was tested on human endothelial cells. Significant effects were obtained at a fraction of <3 KDa, in particular at a concentration of 0.13 µg/mL. The T-scratch test was also performed, with positive results in all fractions tested.

Tilapia fish waste: An asset for tissue engineering - A review

Fisheries and aquaculture output have exploded due to an alarming increase in consumption due to the global understanding of the nutritional advantages of fish. Inadvertently, the methods produce a massive amount of fish waste, posing a serious environmental threat. Recycling this waste has now become a major point of controversy that must be resolved. It is critical to emphasize the utility of discarded marine by-products for the creation of high-value commodities such as marine collagen (MC), which can be considered a sustainable solution. Because of its biocompatibility, biodegradability, safety, minimal immunogenicity, and low production costs, MC has various benefits over terrestrial collagen. Many academics have recently become interested in the use of MC as a scaffold. This review focuses on the intriguing contribution of MC in the production of MC-based scaffolds.

Food waste biorefinery towards circular economy in Australia

Staggering amounts of food waste are produced in Australia, and this review provides food waste based biorefinery opportunities in moving towards a circular economy in Australia. The current food waste scenario in Australia including an overview of primary food waste sources, government regulation, and current management practices is presented. The major food waste streams include fruit and vegetable (waste from wine grapes, citrus, apple, potato, and tomato), nuts (almond processing waste), seafood (Fish waste), dairy whey, sugarcane bagasse, and household and businesses. The composition of these waste streams indicated their potential for use in biorefineries to produce value-added products via various pathways combining direct extraction and biological and thermochemical conversion. Finally, the efforts made in Australia to utilize food waste as a resource, as well as the challenges and future directions to promote the development of concrete and commercially viable technologies for food waste biorefinery, are described.

Harnessing value and sustainability: Fish waste valorization and the production of valuable byproducts

The valorization of by-products, that are residual materials resulting from commercial product manufacturing, holds significant potential in various industries such as food, agrochemical, medical, and pharmaceutical sectors. This chapter explores the utilization of fish waste as a means to achieve sustainability in fish resources and enhance the production of profitable products. By developing cost-effective technologies, the abundant global supply of fish by-products can be transformed into low-cost sources of proteins and functional hydrolysates. This alternative approach in the food industry utilizes fish and seafood waste to generate valuable compounds with nutritional and functional properties, surpassing those found in traditional mammal products. Despite being commonly discarded, fish heads, viscera, skin, tails, blood, and seafood shells contain a wealth ofminerals, lipids, amino acids, polysaccharides, and proteins suitable for human health applications. This chapter presents an exploration of the various products and bioactive compounds that can be derived from seafood waste, contributing to a more sustainable and value-driven future.

Feasibility of Enzymatic Protein Extraction from a Dehydrated Fish Biomass Obtained from Unsorted Canned Yellowfin Tuna Side Streams: Part I

This study presents for the first time a scalable process for the extraction of valuable proteins starting from samples of unsorted mixed tuna scraps which were previously dehydrated by an industrial patented process. The aims of this work were both to avoid the onerous sorting step of tuna leftovers, which generally consists of isolating skin and bones for collagen/gelatin extraction, and to improve the logistic of managing highly perishable biomass thanks to the reduction in its volume and to its microbiological stabilization. In view of a zero-waste economy, all the protein fractions (namely, non-collagenous proteins NCs and ALKs, gelatin, and hydrolyzed gelatin peptides, HGPs) isolated in the proposed single cascade flowchart were stabilized and preliminarily characterized. The extraction flowchart proposed allows one to obtain the following most promising compounds: 1.7 g of gelatin, 3.2 g of HGPs, and 14.6 g of NCs per 100 g of dehydrated starting material. A focus on oven-dried gelatin was reported in terms of proximate analysis, amino acid composition, color parameters, FT-IR spectrum, pH, and viscoelastic properties (5 mPa·s of viscosity and 14.3 °C of gelling temperature). All the obtained extracts are intended to be exploited in food supplements, feed, fertilizers/plant bio-stimulants, packaging, and the cosmetic industry.

Diverse uses of valuable seafood processing industry waste for sustainability: a review

Seafoods are rich in untapped bioactive compounds that have the potential to provide novel ingredients for the development of commercial functional foods and pharmaceuticals. Unfortunately, a large portion of waste or discards is generated in commercial processing setups (50-80%), which is wasted or underutilized. These by-products are a rich source of novel and valuable biomolecules, including bioactive peptides, collagen and gelatin, oligosaccharides, fatty acids, enzymes, calcium, water-soluble minerals, vitamins, carotenoids, chitin, chitosan and biopolymers. These fish components may be used in the food, cosmetic, pharmaceutical, environmental, biomedical and other industries. Furthermore, they provide a viable source for the production of biofuels. As a result, the current review emphasizes the importance of effective by-product and discard reduction techniques that can provide practical and profitable solutions. Recognizing this, many initiatives have been initiated to effectively use them and generate income for the long-term sustainability of the environment and economic framework of the processing industry. This comprehensive review summarizes the current state of the art in the sustainable valorisation of seafood by-products for human consumption. The review can generate a better understanding of the techniques for seafood waste valorisation to accelerate the sector while providing significant benefits.

Tuna sidestream valorization: a circular blue bioeconomy approach

Tuna is an economically significant seafood, harvested throughout the world, and is heavily traded due to its high nutritional quality and consumer acceptance. Tuna meat is rich in essential nutrients such as amino acids, polyunsaturated fatty acids (PUFA), and trace minerals. The huge volume of solid and liquid sidestreams generated during the processing stages of tuna is creating environmental and socioeconomic challenges in coastal areas. Different products such as fish meal, protein hydrolysates, collagen, enzymes, oil, and bone powder can be produced from tuna sidestreams. Using different nutrient recovery technologies like enzymatic hydrolysis, chemical processing, and green technologies, various categories of product value chains can be created in line with the conventional processing industry. This review attempts to provide a route map for the tuna industry for achieving the circular blue-bioeconomic objectives and reorient the irregular utilization pattern into a sustainable and inclusive path.

The evolution of information and communications technology in the fishery industry: The pathway for marine sustainability

There is reason for concern, given the history of technology in the seas. Too often, the extinction and contamination of marine species have been exacerbated by technical advancements and more potent fisheries equipment. By considering the roles of fisheries production, information and communication technology, human capital, governance, carbon dioxide emissions, and economic growth from 1990 to 2022, this paper seeks to investigate the dynamic effect of ICT on the sustainability of the fisheries industry in 27 European countries. The findings showed a substantial positive link between information and communication technology and the fisheries sector at higher quantiles using the new Method of Moments Quantile Regression (MMQR) with fixed effects. Additionally, in the EU27 nations, the impact of economic growth was favorably significant across most quantiles. The findings show that the EU14 developed nations have greater ICT and economic development than the EU13 underdeveloped countries, which significantly benefits fisheries sustainability. At lower quantiles, the data revealed a significant positive association between human capital and the fisheries sector. Results show that developing countries in the EU13 have more significant human capital than industrialized nations in the EU14, which considerably benefits fisheries sustainability. On the other hand, across all quantiles in the EU27 area, the findings revealed a substantial positive link between carbon dioxide emissions and the fisheries sector. EU14 developed countries have a larger significant positive magnitude between carbon dioxide emissions and fisheries output than the EU13 underdeveloped nations. To accomplish sustainable development objectives, this study provides policymakers insight into how to encourage technological transmission factors in the EU14 and EU13 nations via effective and environmentally friendly technology in the fisheries sector.

Fish-Derived Protein Hydrolysates Increase Insulin Sensitivity and Alter Intestinal Microbiome in High-Fat-Induced Obese Mice

Obesity and type 2 diabetes are characterized by low-grade systemic inflammation and glucose intolerance, which can be partially controlled with nutritional interventions. Protein-containing nutritional supplements possess health-promoting benefits. Herein, we examined the effect of dietary supplementation with protein hydrolysates derived from fish sidestreams on obesity and diabetes, utilizing a mouse model of High-Fat Diet-induced obesity and type 2 diabetes. We examined the effect of protein hydrolysates from salmon and mackerel backbone (HSB and HMB, respectively), salmon and mackerel heads (HSH and HMH, respectively), and fish collagen. The results showed that none of the dietary supplements affected weight gain, but HSH partially suppressed glucose intolerance, while HMB and HMH suppressed leptin increase in the adipose tissue. We further analyzed the gut microbiome, which contributes to the metabolic disease implicated in the development of type 2 diabetes, and found that supplementation with selected protein hydrolysates resulted in distinct changes in gut microbiome composition. The most prominent changes occurred when the diet was supplemented with fish collagen since it increased the abundance of beneficial bacteria and restricted the presence of harmful ones. Overall, the results suggest that protein hydrolysates derived from fish sidestreams can be utilized as dietary supplements with significant health benefits in the context of type 2 diabetes and diet-induced changes in the gut microbiome.

Anti-fatigue effect of glycoprotein from hairtail (Trichiurus lepturus) by-products in a behavioral mouse model

Hairtail (Trichiurus lepturus) is a kind of abundant marine fish, and its by-products contain rich protein resources, which can be better exploited and utilized in the food industry. In this study, the glycoprotein of hairtail by-products (GHB) was extracted using ultrasonic-assisted salt solution extraction with hairtail by-products as the raw material. The anti-fatigue effect of GHB was explored by mouse behavior experiments (shuttle box test, open field test and load swimming test). The results showed that the active escape times of the GHB group increased compared with the blank group in the shuttle box test, and the GHB group stayed in the central area for more time in the open field test. At the same time, the exhaustive swimming time of high-dose-group mice was 122.01% longer than that of the blank control group. GHB can improve the memory learning ability and activity of mice, and exert its anti-fatigue effect by eliminating excessive free radicals, slowing the metabolism of amino acids and proteins, and increasing glycogen reserves. This study provides a theoretical basis for the function mechanism of glycoprotein of hairtail by-products and the development of supplementary material in functional foods.

Chlorogenic Acid Inhibits Rahnella aquatilis KM25 Growth and Proteolytic Activity in Fish-Based Products

This work verified the antiproliferative and antiproteolytic activities of chlorogenic acid against Rahnella aquatilis KM25, a spoilage organism of raw salmon stored at 4 °C. Chlorogenic acid limited the growth of R. aqatilis KM25 in vitro at a concentration of 2.0 mg/mL. The dead (46%), viable (25%), and injured (20%) cell subpopulations were identified by flow cytometry following treatment of R. aquatilis KM25 with the examined agent. The exposure of R. aquatilis KM25 to chlorogenic acid altered its morphology. Changes in cell dimensions, mostly in length parameters from 0.778 µm to 1.09 µm, were found. The length of untreated cells ranged from 0.958 µm to 1.53 µm. The RT-qPCR experiments revealed changes in the expression of genes responsible for the proliferation and proteolytic activity of cells. Chlorogenic acid caused a significant reduction in the mRNA levels of the ftsZ, ftsA, ftsN, tolB, and M4 genes (-2.5, -1.5, -2.0, -1.5, and -1.5, respectively). In situ experiments confirmed the potential of chlorogenic acid to limit bacterial growth. A similar effect was noted in samples treated with benzoic acid, where the growth inhibition of R. aquatilis KM25 was 85-95%. Reduction of microbial R. aquatilis KM25 proliferation significantly limited total volatile base nitrogen (TVB-N) and trimethylamine (TMA-N) formation during storage, extending the shelf life of model products. The TVB-N and TMA-N parameters did not exceed the upper levels of the maximum permissible limit of acceptability. In this work, the TVB-N and TMA-N parameters were 10-25 mg/100 g and 2.5-20.5 mg/100 g, respectively; for samples with benzoic acid-supplemented marinades, the parameters TVB-N and TMA-N were 7.5-25.0 mg/100 g and 2.0-20.0 mg/100 g, respectively. Based on the results of this work, it can be concluded that chlorogenic acid can increase the safety, shelf life, and quality of fishery products.

Reduced Chitosan as a Strategy for Removing Copper Ions from Water

Toxic heavy metals are priority pollutants in wastewater, commonly present in dangerous concentrations in many places across the globe. Although in trace quantities copper is a heavy metal essential to human life, in excess it causes various diseases, whereby its removal from wastewater is a necessity. Among several reported materials, chitosan is a highly abundant, non-toxic, low-cost, biodegradable polymer, comprising free hydroxyl and amino groups, that has been directly applied as an adsorbent or chemically modified to increase its performance. Taking this into account, reduced chitosan derivatives (RCDs 1-4) were synthesised by chitosan modification with salicylaldehyde, followed by imine reduction, characterised by RMN, FTIR-ATR, TGA and SEM, and used to adsorb Cu(II) from water. A reduced chitosan (RCD3), with a moderate modification percentage (43%) and a high imine reduction percentage (98%), proved to be more efficient than the remainder RCDs and even chitosan, especially at low concentrations under the best adsorption conditions (pH 4, R_S/L = 2.5 mg mL^-1). RCD3 adsorption data were better described by the Langmuir-Freundlich isotherm and the pseudo-second-order kinetic models. The interaction mechanism was assessed by molecular dynamics simulations, showing that RCDs favour Cu(II) capture from water compared to chitosan, due to a greater Cu(II) interaction with the oxygen of the glucosamine ring and the neighbouring hydroxyl groups.

Trends in fisheries waste utilization: a valuable resource of nutrients and valorized products for the food industry

The rise in fisheries production worldwide has caused a remarkable increase in associated anthropogenic waste. This poses significant concerns due to adverse environmental impacts and economic losses. Owing to its renewability, high abundance, and potential as a rich source of many nutrients and bioactive compounds, strategies have been developed to convert fish waste into different value-added products. Conventional and improved methods have been used for the extraction of biomolecules from fish waste. The extracted fish waste-derived value-added products such as enzymes, peptides, fish oil, etc. have been used to fortify different food products. This review aims to provide an overview of the nature and composition of fish waste, strategies for extracting biomolecules from fish waste, and the potential application of fish waste as a source of calcium and other nutrients in food fortification and animal feed has been discussed. In context to fishery waste mitigation, valorization, and circular bioeconomy approach are gaining momentum, aiming to eliminate waste while producing high-quality value-added food and feed products from fishery discards.

Recycling of hyoscyamine 6β-hydroxylase for the in vitro production of anisodamine and scopolamine

The tropane alkaloids hyoscyamine, anisodamine, and scopolamine are extensively used medicines. In particular, scopolamine has the greatest value in the market. Hence, strategies to enhance its production have been explored as an alternative to traditional field-plant cultivation. In this work, we developed biocatalytic strategies for the transformation of hyoscyamine into its products utilizing a recombinant Hyoscyamine 6β-hydroxylase (H6H) fusion protein to the chitin-binding domain of the chitinase A1 from Bacillus subtilis (ChBD-H6H). Catalysis was carried out in batch, and recycling of H6H constructions was performed via affinity-immobilization, glutaraldehyde crosslinking, and adsorption-desorption of the enzyme to different chitin matrices. ChBD-H6H utilized as free enzyme achieved complete conversion of hyoscyamine in 3- and 22-h bioprocesses. Chitin particles demonstrated to be the most convenient support for ChBD-H6H immobilization and recycling. Affinity-immobilized ChBD-H6H operated in a three-cycle bioprocess (3 h/cycle, 30 °C) yielded in the first and third reaction cycle 49.8% and 22.2% of anisodamine and 0.7% and 0.3% of scopolamine, respectively. However, glutaraldehyde crosslinking decreased enzymatic activity in a broad range of concentrations. Instead, the adsorption-desorption approach equaled the maximal conversion of the free enzyme in the first cycle and retained higher enzymatic activity than the carrier-bound strategy along the consecutive cycles. The adsorption-desorption strategy permitted the reutilization of the enzyme in a simple and economical manner while exploiting the maximal conversion activity displayed by the free enzyme. This approach is valid since other enzymes present in the E. coli lysate do not interfere with the reaction. KEY POINTS: • A biocatalytic system for anisodamine and scopolamine production was developed. • Affinity-immobilized ChBD-H6H in ChP retained catalytic activity. • Enzyme-recycling by adsorption-desorption strategies improves product yields.

Agro-Food Waste as an Ingredient in Functional Beverage Processing: Sources, Functionality, Market and Regulation

Waste generated from the agro-food industry represents a concerning environmental, social and economic issue. The Food and Agriculture Organization of the United Nations defines food waste as all food that decreases in quantity or quality to the extent that it is thrown out by food service providers and consumers. The FAO reports that 17% of worldwide food production may be wasted. Food waste may include fresh products, food close to the expiration date discarded by retailers and food products from household kitchens and eating establishments. However, food waste offers different possibilities to extract functional ingredients from different sources, such as dairy, cereals, fruits, vegetables, fibers, oils, dye and bioactive compounds. The optimization of agro-food waste as an ingredient will help in the development and innovation of food products to generate functional food and beverages to prevent and treat several diseases in consumers.

Collagen, protein hydrolysates and chitin from by-products of fish and shellfish: An overview

Waste processing from fish and seafood manufacturers represents a sustainable option to prevent environmental contamination, and their byproducts offer different benefits. Transforming fish and seafood waste into valuable compounds that present nutritional and functional properties compared to mammal products becomes a new alternative in Food Industry. In this review, collagen, protein hydrolysates, and chitin from fish and seafood byproducts were selected to explain their chemical characteristics, production methodologies, and possible future perspectives. These three byproducts are gaining a significant commercial market, impacting the food, cosmetic, pharmaceutical, agriculture, plastic, and biomedical industries. For this reason, the extraction methodologies, advantages, and disadvantages are discussed in this review.

Effective Endotoxin Removal from Chitosan That Preserves Chemical Structure and Improves Compatibility with Immune Cells

Chitosan is one of the most researched biopolymers for healthcare applications, however, being a naturally derived polymer, it is susceptible to endotoxin contamination, which elicits pro-inflammatory responses, skewing chitosan's performance and leading to inaccurate conclusions. It is therefore critical that endotoxins are quantified and removed for in vivo use. Here, heat and mild NaOH treatment are investigated as facile endotoxin removal methods from chitosan. Both treatments effectively removed endotoxin to below the FDA limit for medical devices (<0.5 EU/mL). However, in co-culture with peripheral blood mononuclear cells (PBMCs), only NaOH-treated chitosan prevented TNF-α production. While endotoxin removal is the principal task, the preservation of chitosan's structure is vital for the synthesis and lysozyme degradation of chitosan-based hydrogels. The chemical properties of NaOH-treated chitosan (by FTIR-ATR) were significantly similar to its native composition, whereas the heat-treated chitosan evidenced macroscopic chemical and physical changes associated with the Maillard reaction, deeming this treatment unsuitable for further applications. Degradation studies conducted with lysozyme demonstrated that the degradation rates of native and NaOH-treated chitosan-genipin hydrogels were similar. In vitro co-culture studies showed that NaOH hydrogels did not negatively affect the cell viability of monocyte-derived dendritic cells (moDCs), nor induce phenotypical maturation or pro-inflammatory cytokine release.

Fatty Acids in Waste Tissues: The Nutraceutical Value of Gonads and Livers from the Moroccan Hypophthalmichthys molitrix and Cyprinus carpio Fishes

Fishes are an important component of human nutrition, mainly acting as source of essential fatty acids in the prevention of cardiovascular disorders. The increase in their consumption has led to a growth of fishes waste; therefore, the disposal and recycling of waste has become a key issue to address, in accordance with circular economy principles. The Moroccan Hypophthalmichthys molitrix and Cyprinus carpio fishes, living in freshwater and marine environments, were collected at mature and immature stages. The fatty acid (FA) profiles of liver and ovary tissues were investigated by GC-MS and compared with edible fillet tissues. The gonadosomatic index, the hypocholesterolemic/hypercholesterolemic ratio, and the atherogenicity and thrombogenicity indexes were measured. Polyunsaturated fatty acids were found to be abundant in the mature ovary and fillet of both species, with a polyunsaturated fatty acids/saturated fatty acids ratio ranging from 0.40 to 1.06 and a monounsaturated fatty acids/polyunsaturated fatty acids ratio between 0.64 and 1.84. Saturated fatty acids were found to be highly abundant in the liver and gonads of both species (range 30-54%), as well as monounsaturated fatty acids (range 35-58%). The results suggested that the exploitation of fish wastes, such as the liver and ovary, may represent a sustainable strategy for the achievement of high value-added molecules with nutraceutical potential.

In Silico Methodologies to Improve Antioxidants' Characterization from Marine Organisms

Marine organisms have been reported to be valuable sources of bioactive molecules that have found applications in different industrial fields. From organism sampling to the identification and bioactivity characterization of a specific compound, different steps are necessary, which are time- and cost-consuming. Thanks to the advent of the -omic era, numerous genome, metagenome, transcriptome, metatranscriptome, proteome and microbiome data have been reported and deposited in public databases. These advancements have been fundamental for the development of in silico strategies for basic and applied research. In silico studies represent a convenient and efficient approach to the bioactivity prediction of known and newly identified marine molecules, reducing the time and costs of "wet-lab" experiments. This review focuses on in silico approaches applied to bioactive molecule discoveries from marine organisms. When available, validation studies reporting a bioactivity assay to confirm the presence of an antioxidant molecule or enzyme are reported, as well. Overall, this review suggests that in silico approaches can offer a valuable alternative to most expensive approaches and proposes them as a little explored field in which to invest.

Turning Food Protein Waste into Sustainable Technologies

For each kilogram of food protein wasted, between 15 and 750 kg of CO2 end up in the atmosphere. With this alarming carbon footprint, food protein waste not only contributes to climate change but also significantly impacts other environmental boundaries, such as nitrogen and phosphorus cycles, global freshwater use, change in land composition, chemical pollution, and biodiversity loss. This contrasts sharply with both the high nutritional value of proteins, as well as their unique chemical and physical versatility, which enable their use in new materials and innovative technologies. In this review, we discuss how food protein waste can be efficiently valorized not only by reintroduction into the food chain supply but also as a template for the development of sustainable technologies by allowing it to exit the food-value chain, thus alleviating some of the most urgent global challenges. We showcase three technologies of immediate significance and environmental impact: biodegradable plastics, water purification, and renewable energy. We discuss, by carefully reviewing the current state of the art, how proteins extracted from food waste can be valorized into key players to facilitate these technologies. We furthermore support analysis of the extant literature by original life cycle assessment (LCA) examples run ad hoc on both plant and animal waste proteins in the context of the technologies considered, and against realistic benchmarks, to quantitatively demonstrate their efficacy and potential. We finally conclude the review with an outlook on how such a comprehensive management of food protein waste is anticipated to transform its carbon footprint from positive to negative and, more generally, have a favorable impact on several other important planetary boundaries.

Anti-inflammatory effects of fish bone fermented using Monascus purpureus in LPS-induced RAW264.7 cells by regulating NF-κB pathway

Fish bones are the by-products of aquatic and fishery processing, which are often discarded. However, it has been considered having health-promoting by containing many essential nutrients. This study investigates the anti-inflammatory effect of fish bone fermented by Monascus purpureus (FBF) and the NF-κB pathway regulation mechanism in lipopolysaccharides (LPS)-induced RAW 264.7 cells. FBF has inhibited the production of PGE2 (prostaglandin E2), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in LPS-induced RAW264.7 cells. The FBF has significantly inhibited mRNA expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Moreover, FBF has suppressed activation of NF-κB (nuclear factor kappa-B) by increasing IκB mRNA expression and reduced of p65, p50 mRNA expression, as well as nuclear NF-κB DNA binding activity in LPS-induced RAW 246.7 cells. These findings demonstrate that FBF has inhibited LPS-induced inflammation by subsiding the activation of NF-κB in RAW 246.7 cells, implying that FBF could be employed as a promising natural product.