Increasing consumer demand for seafood, combined with concern over the health of our oceans, has led to many initiatives aimed at tackling destructive fishing practices and promoting the sustainability of fisheries. An important global threat to sustainable fisheries is Illegal, Unreported and Unregulated (IUU) fishing, and there is now an increased emphasis on the use of trade measures to prevent IUU-sourced fish and fish products from entering the international market. Initiatives encompass new legislation in the European Union requiring the inclusion of species names on catch labels throughout the distribution chain. Such certification measures do not, however, guarantee accuracy of species designation. Using two DNA-based methods to compare species descriptions with molecular ID, we examined 386 samples of white fish, or products labeled as primarily containing white fish, from major UK supermarket chains. Species specific real-time PCR probes were used for cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) to provide a highly sensitive and species-specific test for the major species of white fish sold in the UK. Additionally, fish-specific primers were used to sequence the forensically validated barcoding gene, mitochondrial cytochrome oxidase I (COI). Overall levels of congruence between product label and genetic species identification were high, with 94.34% of samples correctly labeled, though a significant proportion in terms of potential volume, were mislabelled. Substitution was usually for a cheaper alternative and, in one case, extended to a tropical species. To our knowledge, this is the first published study encompassing a large-scale assessment of UK retailers, and if representative, indicates a potentially significant incidence of incorrect product designation.
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Value added products such as fish protein hydrolysates (FPH) can be produced from fish by-products. Lipid oxidation and bad taste are the major challenge in the commercialization of bioactive FPH. The aim of this research was to study the production of high quality FPH from fish by-products prepared by enzymatic hydrolysis using a natural antioxidant extracted from the Icelandic brown algae Fucus vesiculosus (Fv). FPH were produced from cod waste material; ie cod bone mince, in the absence and presence of an Fv extract (Fv-e). Oxidation during FPH production was evaluated (lipid hydroperoxides and thiobarbituric acid reactive substances). The FPH were sensory analyzed (generic descriptive analysis) and in vitro antioxidant activity was evaluated. Results show that Fv–e contributed to better tasting FPH with regard to bitter, soap, fish oil and rancidity taste. Results from the oxidation and antioxidant activity assays indicated a protecting effect of Fv-e during processing.
Fish protein hydrolysates (FPH) have many desirable properties, however heating and shifts in pH can cause oxidation during enzymatic hydrolysis. The objective was to investigate oxidative processes during enzymatic hydrolysis of fish protein and the impact of oxidation on the antioxidant and immunomodulating ability of FPH. Protease P “Amano” 6 was used to hydrolyze cod protein in the presence and absence of pro-oxidants at pH 8 and 36 ° C to achieve 20% degree of hydrolysis. Results from thiobarbituric acid reactive substances (TBARS) and sensory analysis indicate that oxidation can develop rapidly during hydrolysis. A cellular antioxidant assay using a HepG2 cell model indicated a negative impact of oxidation products on antioxidant properties of the FPH while results obtained in chemical assays showed a negligible impact. Results from a dendritic cell model indicating that oxidation products may affect anti-inflammatory activity in the body. This study provides important information regarding bioactive FPH.
Agriculture and agro-industry are important sectors in the economies of most developing countries, where they provide the main source of livelihoods for the majority of the poor. The lack of a sustainable supply of affordable energy is a major constraint to the development of these sectors in developing countries. Traditionally, geothermal energy has been utilized mainly to generate electricity; however, it can be harnessed for other important uses in agriculture and agro-industry. Developing countries endowed with this renewable energy source have ample potential to use it in advancing their agriculture and agro-industry sectors. This book reviews the use of geothermal energy in agriculture and agro-industry around the world. With a simple format and copious illustrations and models, the book is accessible to a wide range of interested readers, including those with no technical background. It shows that geothermal resources have the potential to provide long-term, secure energy for the agriculture and food industry in both developed and developing countries. Constraints and challenges that should be addressed before this potential can be fully achieved are also discussed.
Antioxidant and sensory properties of Nile tilapia protein hydrolysates prepared by one- and two-step hydrolysis using commercial proteases were investigated. Hydrolysates prepared using single protease including Alcalase (HA), Flavourzyme (HF), Protamex (HPr) and papain (HPa) had increases in antioxidant activities as the degree of hydrolysis (DH) increased up to 40 % (P<0.05). Amongst all hydrolysates, HA having 40 % DH showed the highest antioxidant activities. When HA was further hydrolyzed by papain, the resulting hydrolyzate (HAPa) exhibited the highest antioxidant activities for all assays tested (P<0.05). ABTS radical scavenging activity and metal chelating of HAPa generally remained constant in a wide pH range (1–11) and during heating at 30–100 ° C. Both activities increased in the simulated gastrointestinal tract model system, especially in intestinal condition. HAPa (100–1,000 ppm) could retard lipid oxidation in β-carotene-linoleate and lecithin-liposome model systems in a dose dependent manner. Peptides in both HA and HAPa with molecular weight of 513 Da and 1,484 Da possessed the strongest ABTS radical scavenging activity and metal chelating activity, respectively. The amino acid profile of both HA and HAPa contained a high amount of hydrophobic amino acids (38.26–38.85 %) and had glutamic acid / glutamine, lysine and aspartic acid / asparagine as the dominant amino acids. However, HAPa showed a higher acceptability than did HA, owing to the lower bitterness. Therefore, the use of Alcalase in combination with papain for hydrolysis of protein isolate rendered the hydrolyzate with antioxidant properties and reduced bitterness, which could serve as the functional supplement.
Antioxidant activities of protein hydrolyzate prepared from Nile tilapia protein isolate using Alcalase (HA), Alcalase followed by papain (HAPa) and their Sephadex G-25 fractions (FHA and FHAPa) were investigated in both chemical and cellular based models. Amongst all samples, FHAPa showed the highest chemical antioxidant activities, however it had no metal chelation activity. Cellular antioxidant ability of HA, HAPa and their fractions against H2O2 and AAPH induced oxidative damage of HepG2 cell and DNA were tested. When cells were pretreated with all hydrolysates or fractions at different concentrations (0.5–2 mg / mL) in the absence and presence of 50 μM Trolox, cell viability was in the range of 91.10–111.40 %. However, no difference in cell viability was observed among samples having various concentrations (P> 0.05). Cell reactive oxygen species (ROS) generation as mediated by H2O2 and AAPH decreased with treatment of hydrolysates or their fractions, especially in combination with 50 μM Trolox. FHAPa effectively inhibited H2O2 and peroxyl radical induced DNA scission in a dose dependent manner. Therefore, Nile tilapia protein hydrolysates could serve as a functional food ingredient.
In northern Europe a number of fish products are prepared in such a way that biochemical and microbial action can take place. These are complex processes for which there are few available scientific studies. This article covers the origin, manufacturing, characteristics, and consumption of traditional fermented fish products, including sour herring from Sweden, rakfisk from Norway, shark from Iceland, and the barrel-salted herring that was commonly produced in most of northern Europe.
A prototype for a Responsive Fisheries Management System (RFMS) was developed in the context of the European FP7 project EcoFishMan and tested on the Portuguese crustacean trawl fishery. Building on Results Based Management principles, RFMS involves the definition of specific and measurable objectives for a fishery by the relevant authorities but allows resource users the freedom to find ways to achieve the objectives and to provide adequate documentation. Taking into account the main goals of the new Common Fisheries Policy, such as sustainable utilization of the resources, end of discards and unwanted catches, a management plan for the Portuguese crustacean trawl fishery was developed in cooperation with the fishing industry, following the process and design laid out in the RFMS concept. The plan considers biological, social and economic goals and assigns a responsibility for increased data collection to the resource users. The performance of the plan with regard to selected indicators was evaluated through simulations. In this paper the process towards an RFMS is described and the lessons learned from the interaction with stakeholders in the development of an alternative management plan are discussed.
A number of solutions, with varying efficiency, have been proposed to mitigate discards. In this paper twelve mitigation measures were reviewed by their strengths and weaknesses, along with opportunities and threats, they might entail. How mitigation methods could either support or counteract others was also reviewed. The analyzes of the mitigation measures are based on expert knowledge and experience and supported with existing literature. Discarding is highly variable and is influenced by numerous biological, technical and operational factors as well as social and economic drivers. These influences need to be carefully considered when designing management approaches. Finally, all reforms must be carefully considered within the context of a broader management system. The full management system needs to be thought of coherently to create an incentive framework that motivates fishers to avoid unwanted catches. It is only in this setting that discard mitigation methods may be potentially effective.
The reformed Common Fisheries Policy (CFP), adopted by the European Union in 2013, aims to achieve sustainable exploitation of marine resources. Beyond the mainstream of stakeholders' engagement, the literature increasingly calls for shared accountability in fisheries management. In such scenarios, identifying stakeholders' insights becomes critical for a successful design of innovative management approaches. This paper analyzes how the stakeholders perceive a results-based management system for four fisheries in different European sea-basins as well as at a pan-European level. The results indicate a need for adaptive and participatory management approaches, building on regional adaptations within transparent and plural frameworks for fisheries. To succeed, the system should explicitly address its associated public and private costs; neither participation nor accountability comes for free.