Glycosaminoglycans (GAGs) in marine animals are different to those of terrestrial organisms, mainly in terms of molecular weight and sulfation. The therapeutic properties of GAGs are related to their ...ability to interact with proteins, which is very much influenced by sulfation position and patterns. Since currently GAGs cannot be chemically synthesized, they are sourced from natural products, with high intra- but also inter-species variability, in terms of chain length, disaccharide composition and sulfation pattern. Consequently, sulfated GAGs are the most interesting molecules in the marine environment and constitute the focus of the present review. In particular, chondroitin sulfate (CS) appears as the most promising compound. CS-E chains GlcA-GalNAc(4S,6S) extracted from squid possess antiviral and anti-metastatic activities and seem to impart signalling properties and improve the mechanical performance of cartilage engineering constructs; Squid CS-E and octopus CS-K GlcA(3S)-GalNAc(4S), dermatan sulfate (DS) from sea squirts -iK units, IdoA(3S)-GalNAc(4S) and sea urchins -iE units, IdoA-GalNAc(4S,6S) and hybrids CS/DS from sharks (-B/iB GlcA/IdoA(2S)-GalNAc(4S), -D/iD GlcA/IdoA(2S)-GalNAc(6S) and –E/iE units GlcA/IdoA-GalNAc(4S,6S)) promote neurite outgrowth and could be valuable materials for nerve regeneration. Also displaying antiviral and anti-metastatic properties, a rare CS with fucosylated branches isolated from sea cucumbers is an anticoagulant and anti-inflammatory agent. In this same line, marine heparin extracted from shrimp and sea squirt has proven anti-inflammatory properties, with the added advantage of decreased risk of bleeding because of its low anticoagulant activity.
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•Marine glycosaminoglycans (GAGs) are different to terrestrial GAGs in terms of molecular weight and sulfation.•Sulfated GAGs are the most interesting therapeutic molecules in the marine environment.•Squid CS posses antiviral and anti-metastatic activities and improves the properties of materials for cartilage engineering.•Octopus and squid CS, shark CS/DS and DS from sea squirts and sea urchins could be valuable in nerve regeneration.•Sea cucumber fucosylated CS displays antiviral, anti-metastatic, anticoagulant and anti-inflammatory properties.
Fish discards are of major concern in new EU policies. Alternatives for the management of the new biomass that has to be landed is compulsory. The production of bioactive compounds from fish protein ...hydrolysates (FPH) has been explored in recent years. However, the viability of
discards, which might account for up to 90-100% of captures in mixed trawler, gillnet, and longline industrial fisheries, to produce FPH from the muscle with bioactivities has still not been studied in terms of the optimization of the experimental conditions to enhance its production. The effect of
and temperature on the hydrolysis of the
muscle was mediated by three commercial proteases using response surface methodology. Temperatures of 64.6 °C and 60.8 °C and pHs of 9.40 and 8.90 were established as the best hydrolysis conditions for Alcalase and Esperase, respectively. Optimization of the best conditions for the maximization of antihypertensive and antioxidant activities was performed. Higher Angiotensin-converting enzyme (ACE) activity was found with Esperase. The
optimum and temperature optimum for antioxidants were 55 °C/pH8.0 for ABTS/DPPH-Esperase, 63.1 °C/pH9.0 for DPPH-Alcalase, and 55 °C/pH9.0 for ABTS-Alcalase. No hydrolysis was detected when using Protamex.
During fish processing operations, such as skinning and filleting, the removal of collagen-containing materials can account for up to 30% of the total fish byproducts. Collagen is the main structural ...protein in skin, representing up to 70% of dry weight depending on the species, age and season. It has a wide range of applications including cosmetic, pharmaceutical, food industry, and medical. In the present work, collagen was obtained by pepsin extraction from the skin of two species of teleost and two species of chondrychtyes with yields varying between 14.16% and 61.17%. The storage conditions of the skins appear to influence these collagen extractions yields. Pepsin soluble collagen (PSC) was enzymatically hydrolyzed and the resultant hydrolysates were ultrafiltrated and characterized. Electrophoretic patterns showed the typical composition of type I collagen, with denaturation temperatures ranged between 23 °C and 33 °C. In terms of antioxidant capacity, results revealed significant intraspecific differences between hydrolysates, retentate, and permeate fractions when using
-Carotene and DPPH methods and also showed interspecies differences between those fractions when using DPPH and ABTS methods. Under controlled conditions, PSC hydrolysates from
,
,
and
provide a valuable source of peptides with antioxidant capacities constituting a feasible way to efficiently upgrade fish skin biomass.
The objective of this report was to investigate the isolation and recovery of different biocompounds and bioproducts from wastes (skins and heads) that were obtained from five species discarded by ...fishing fleets (megrim, hake, boarfish, grenadier, and Atlantic horse mackerel). Based on chemical treatments, enzymatic hydrolysis, and bacterial fermentation, we have isolated and produced gelatinous solutions, oils that are rich in omega-3, fish protein hydrolysates (FPHs) with antioxidant and antihypertensive activities, and peptones. FPHs showed degrees of hydrolysis higher than 13%, with soluble protein concentrations greater than 27 g/L and in vitro digestibilities superior to 90%. Additionally, amino acids compositions were always valuable and bioactivities were, in some cases, remarkable. Peptones that were obtained from FPHs of skin and the heads were demonstrated to be a viable alternative to expensive commercial ones indicated for the production of biomass, lactic acid, and pediocin SA-1 from
.
Fish skins constitute an important fraction of the enormous amount of wastes produced by the fish processing industry, part of which may be valorized through the extraction of gelatins. This research ...exploited the extraction and characterization of gelatins from the skin of three seawater fish species, namely yellowfin tuna (
), blue shark (
), and greenland halibut (
). Characterization included chemical composition, rheology, structure, texture, and molecular weight, whereas extraction studies intended to reduce costly steps during extraction process (reagents concentration, water consumption, and time of processing), while maintaining extraction efficiency. Chemical and physical characterization of the obtained gelatins revealed that the species from which the gelatin was extracted, as well as the heat treatment used, were key parameters in order to obtain a final product with specific properties. Therefore, the extraction conditions selected during gelatin production will drive its utilization into markets with well-defined specifications, where the necessity of unique products is being claimed. Such achievements are of utmost importance to the food industry, by paving the way to the introduction in the market of gelatins with distinct rheological and textural properties, which enables them to enlarge their range of applications.
This study illustrates the optimisation of the experimental conditions of three sequential steps for chondroitin sulphate (CS) recovery from three cartilaginous materials of Scyliorhinus canicula ...by-products. Optimum conditions of temperature and pH were first obtained for alcalase proteolysis of head cartilage (58 °C/pH 8.5/0.1% (v/w)/10 h of hydrolysis). Then, similar optimal conditions were observed for skeletons and fin materials. Enzymatic hydrolysates were subsequently treated with a combination of alkaline hydroalcoholic saline solutions in order to improve the protein hydrolysis and the selective precipitation of CS. Ranges of 0.53-0.64 M (NaOH) and 1.14-1.20 volumes (EtOH) were the levels for optimal chemical treatment depending on the cartilage origin. Finally, selective purification and concentration of CS and protein elimination of samples obtained from chemical treatment, was assessed by a combination of ultrafiltration and diafiltration (UF-DF) techniques at 30 kDa.
Chondroitin sulfate (CS) is a glycosaminoglycan actively researched for pharmaceutical, nutraceutical and tissue engineering applications. CS extracted from marine animals displays different features ...from common terrestrial sources, resulting in distinct properties, such as anti-viral and anti-metastatic. Therefore, exploration of undescribed marine species holds potential to expand the possibilities of currently-known CS. Accordingly, we have studied for the first time the production and characterization of CS from blackmouth catshark (
), a shark species commonly discarded as by-catch. The process of CS purification consists of cartilage hydrolysis with alcalase, followed by two different chemical treatments and ending with membrane purification. All steps were optimized by response surface methodology. According to this, the best conditions for cartilage proteolysis were established at 52.9 °C and
= 7.31. Subsequent purification by either alkaline treatment or hydroalcoholic alkaline precipitation yielded CS with purities of 81.2%, 82.3% and 97.4% respectively, after 30-kDa membrane separation. The molecular weight of CS obtained ranges 53⁻66 kDa, depending on the conditions. Sulfation profiles were similar for all materials, with dominant CS-C (GlcA-GalNAc6S) units (55%), followed by 23⁻24% of CS-A (GlcA-GalNAc4S), a substantial amount (15⁻16%) of CS-D (GlcA2S-GalNAc6S) and less than 7% of other disulfated and unsulfated disaccharides.
In order to promote sustainable fishing practices within European fishing fleets and to avoid the large waste of valuable fish biomass through the practice of fish discarding, the new reform of the ...common fisheries policy includes the obligation of landing all species under total allowable catch (TAC) regulations. The new policy also prohibits the use of specimens under minimum conservation reference size for direct human cons38umption. In this context, it is necessary to find new uses for undersized fish, which might help to alleviate the costs associated with the landing obligation but without prompting the creation of a market. European hake (EH) (
), which is one of the most important commercial fish species for the Spanish fishing industry, with a total TAC for 2018 of 3,7423 t, is used for this study. Consistent with the current policy framework and taking into account the commercial importance of this species, the aim of this work is to study a new strategy for the extraction of collagen from the skin and bone fraction of
undersized discards. Three collagen fractions are successfully isolated for the first time from the skin of
skin and bone discarded raw material: acid-soluble collagen (ASC) fraction 1 and pepsin-soluble collagen (PSC) fraction 2 from the skin and ASC fraction 3 from bones. The total collagen yield of the process is 13.55 ± 3.18% in a dry basis (g collagen/100 g of skin and bone fraction (SBF)) and 47.80 ± 9.83% (g collagen/100 g of collagen determined by the hydroxyproline content in SBF). The three fractions are further characterized by using different physical and chemical analysis techniques, with the conclusion drawn that the triple helix structure is preserved in the three fractions, although ASC fractions (F1 and F3) present more or stronger hydrogen bonds than the PSC fraction (F2). With the process herein presented, deboned and skinned hake specimens could represent an interesting source of high quality type I collagen, which could be useful as a raw material for the biomedical, cosmetic, and nutraceutical industries.
This work investigates the production of hyaluronic acid (H) by Streptococcus equi subsp. zooepidemicus in complex media formulated with peptones obtained from Scyliorhinus canicula viscera ...by-products. Initially, in batch cultures, the greatest productions were achieved using commercial media (3.03 g/L) followed by peptones from alcalase hydrolyzed viscera (2.32 g/L) and peptones from non-hydrolyzed viscera (2.26 g/L). An increase of between 12% and 15% was found in subsequent fed-batch cultures performed on waste peptones. Such organic nitrogen sources were shown to be an excellent low-cost substrate for microbial H, saving more than 50% of the nutrient costs.
•A very fast method for the authentication of cod, Alaska pollock and ling was developed.•A DNA specific PCR coupled with easy detection using a lateral flow dipstick assay was the basis of the ...analysis method.•The developed method was successfully applied to 31 commercial products.
Species-specific lateral flow dipstick (LFD) assays for the identification of Atlantic cod (Gadus morhua), Pacific cod (Gadus macrocephalus), Alaska pollock (Gadus chalcogrammus) and ling (Molva molva) in food products were developed. The method comprises a PCR system with four sets of specific primers, for each target species. This step was also devised to dual-labeling of PCR products with biotin and 6-FAM, which are then easily read on a lateral flow dipstick, upon which these products are immobilized by a fixed biotin-ligand and visualized with anti-FAM antibody-coated gold nanoparticles. Sensitivity and selectivity were determined for each of the developed assays. Validation of the assays was performed with DNA extracted from commercial fish products, the identification of all samples by PCR-LFD was coherent with the results found with DNA sequencing. Target species were successfully detected in analyzed commercial samples, demonstrating the applicability of this method to the rapid analysis of food products.
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