Brewery by-products (yeast and spent grain) as protein sources in rainbow trout (Oncorhynchus mykiss) feeds

A trial was conducted to analyze the effect of the inclusion of yeast and spent grain obtained from breweries in feeds for rainbow trout (Oncorhynchus mykiss), taking into account the availability of these by-products, produced in large quantities in Europe. The ingredients were assayed in both dried and hydrolyzed format and compared with a commercial dried or hydrolyzed yeast. According to the results, the inclusion of 20% yeast and 15% spent grain in the feed, formulated with only 15% inclusion of fish meal, produced similar results in growth among all the groups, a food conversion significantly lower for the control and spent grain formulated feeds, and rainbow trout muscle composition similar to the fish fed with a control commercial feed and showed a protein digestibility of 87%–89% without differences with the commercial yeast. Hydrolysis of the ingredients had no effects on the protein digestibility of the feeds. Protein digestibility of the ingredients was lower for spent grain. An inclusion rate not higher than 15% for spent grain is recommended. These industrial by-products can be a good source to reduce the use of plant-based ingredients and increase the sustainability of both sectors, brewery industry, and aquaculture.info:eu-repo/semantics/publishedVersio

Relevant product categories from mesopelagic fisheries. D3.8

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Brewer’s Spent Dry Yeast Modulates Immunity in Gilthead Sea Bream (Sparus aurata)

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Evaluation of Valorisation Strategies to Improve Grape Stems’ Nutritional Value as an Ingredient for Ruminants’ Diets

Grape stems are a by-product of wine production which is managed as a waste. Animal feeding arises as a potential alternative. However, its practical use may be compromised by its high lignin content. In this sense, hydrolysis emerges as a strategy to increase fibre digestibility. In addition, due to its high and variable moisture content, it should be dried to prevent microbial deterioration and a washing pre-treatment to reduce sugar content becomes necessary to minimize drying problems due to sugar melting at high temperatures. Within this framework, this study assessed the effect of washing and three different hydrolysis on the nutritive value of grape stems. A factorial design was carried out, with washing (with or without) and hydrolysis (without, enzymatic, alkali, and alkali-enzymatic) as factors. When the washing pre-treatment was not applied, only the alkali hydrolysis process maintained in vitro digestibility, but at the expense of a lower fermentation efficiency. When the washing pre-treatment was applied, fibre contents were similar among hydrolysis processes, but the alkali hydrolysis improved in vitro digestibility with similar fermentation efficiency. In conclusion, the alkali hydrolysis maintained or improved the grape stem nutritive value depending on whether the washing pre-treatment was applied or not.This paper is supported by the PRIMA program under grant agreement No 2013, project NEWFEED. The PRIMA program is supported by the European Union

Generation, Characterisation and Identification of Bioactive Peptides from Mesopelagic Fish Protein Hydrolysates Using In Silico and In Vitro Approaches

This study generated bioactive hydrolysates using the enzyme Alcalase and autolysis from mesopelagic fish, including Maurolicus muelleri and Benthosema glaciale. Generated hydrolysates were investigated for their bioactivities using in vitro bioassays, and bioactive peptides were identified using mass spectrometry in active hydrolysates with cyclooxygenase, dipeptidyl peptidase IV and antioxidant activities. In silico analysis was employed to rank identified peptide sequences in terms of overall bioactivity using programmes including Peptide Ranker, PrepAIP, Umami-MRNN and AntiDMPpred. Seven peptides predicted to have anti-inflammatory, anti-type 2 diabetes or Umami potential using in silico strategies were chemically synthesised, and their anti-inflammatory activities were confirmed using in vitro bioassays with COX-1 and COX-2 enzymes. The peptide QCPLHRPWAL inhibited COX-1 and COX-2 by 82.90% (+/−0.54) and 53.84%, respectively, and had a selectivity index greater than 10. This peptide warrants further research as a novel anti-inflammatory/pain relief peptide. Other peptides with DPP-IV inhibitory and Umami flavours were identified. These offer potential for use as functional foods or topical agents to prevent pain and inflammation.publishedVersio

Economic trade-offs of harvesting the ocean twilight zone: An ecosystem services approach

The mesopelagic or ocean twilight zone (OTZ) in the ocean contains huge numbers of fish in a relatively pristine environment and may therefore attract interest as a commercial fishery. In this study we evaluate in economic terms, the likely trade-offs between the different services provided by the mesopelagic layer in the Bay of Biscay and the societal benefits of its commercial exploitation. Benefits arise mainly from the likely use of this group of species as raw material for producing fishmeal and fish oil. Costs are derived from the loss in climate regulating and cultural, services, but also from the loss in the provisioning service of other commercial species. To do so we compare the current non-exploited status with a situation in where mesopelagic fishes are harvested at levels capable of producing the Maximum Sustainable Yield. Results suggest that if mesopelagic fishes are harvested, a mean value of 1.2 million Euro loss in a year will be created in the Bay of Biscay, although in a range between 42 million Euro loss and 48 Euro million benefits. This uncertainty comes, mainly, from the limited existing knowledge of the mesopelagic fishes’ biomass but also from the uncertainty on the biomass of the rest of the species of the studied ecosystem. The large range indicates that a better understanding of the mesopelagic ecosystem is needed, however, results also show that ecosystem services under no exploitation provided by the OTZ could be more valuable than the fishmeal and fish oil that potentially could be obtained from the fishes harvested in this sea layer

Differences in nutrient and undesirable substance concentrations in Maurolicus muelleri across the Bay of Biscay, Norwegian fjords, and the North Sea

IntroductionWe are having pressing issues of global food insecurity and malnutrition. Mesopelagic communities in the North Atlantic have been estimated to have high biomasses of organisms. Some of these low-trophic organisms are known to be nutrient-dense and may thus contribute to food security and nutrition. Here, we aim to understand the variation in nutrient and undesirable substance concentrations in a common mesopelagic species, Maurolicus muelleri in the North Atlantic Ocean.MethodsWe sampled the M. muelleri from the Bay of Biscay (BB), Norwegian fjords (NF), and the North Sea (NS). The concentrations of micro- and macronutrients, undesirable metals, and persistent organic pollutants (POPs) were measured in composite whole fish samples.ResultsWe found no difference across the sampling areas in the selected micronutrients except that the NF and NS samples had higher vitamin A1 concentrations than the BB samples. The NF samples had higher concentrations of fat, fatty acids, and POPs but lower concentrations of cadmium than the BB and NS samples; the differences in fat and fatty acids were only marginal in the NF-BB pair. The BB samples had lower arsenic concentrations than the NS samples, and lower concentrations of erucic acid and mercury than the NF and NS samples. Comparing the measured values against existing EU regulation values for nutrients and undesirable substances for human consumption, we found that the samples from NS and BB may cause food safety concerns due to their high cadmium concentrations, while the M. muelleri from all the sampling areas are qualified as good sources of iron, selenium, vitamin A1, and ω-3 fatty acids.DiscussionThis study confirms that M. muelleri from the North Atlantic Ocean may play an important role in food security and nutrition. However, potential variations in nutrient and undesirable substance concentrations related to seasonality, fish body size, and maturity level shall be taken into consideration prior to exploiting such a marine resource. Further understanding of trophic ecology, life cycles, and productivity of M. muelleri is essential to investigate the drivers behind the observed variation in nutrient and undesirable substance concentrations

Estimated Impact of the Landing Obligation on Raw Material Supplies

The Common Fisheries Policy of the European Union is currently adopting a major change to its methodology, by eliminating discards. One of the questions that arise related with the implementation of the landing obligation (LO) refers to its impact on supplies of unavoidable, unwanted catches (UUC) and how they can be utilized once they have been landed. Introduction of the LO has not only led to a new regime in the fishing activities, but also forced the sector to focus on what to do with significant supplies of fish that previously were thrown overboard. The first step in that work is to provide an overview of current and expected supplies of UUC, where and when they will be landed, what are the available facilities and how the set-up is at the landing harbours to cope with changing supplies. This paper addresses this new situation by focusing on four selected EU fisheries[i]: Bay of Biscay (landings in the Basque country), North Sea, Skagerrak & Kattegat (Danish fleet), the Mediterranean (bottom trawlers landing in Mallorca) and the English Channel (French fleet). Icelandic fisheries are in addition examined to provide an example of a fishery where a LO has been successfully in effect for decades. There are similarities and differences between the fisheries examined, both in regards to expected supplies and expectations when it comes to utilization alternatives in the different regions. [i] Part of the work has taken place in the frame of project DiscardLess (www.discardless.eu), EU H2020, grant agreement No 633680.Proceedings of the Eighteenth Biennial Conference of the International Institute of Fisheries Economics and Trade, held July 11-15, 2016 at Aberdeen Exhibition and Conference Center (AECC), Aberdeen, Scotland, UK

Relevant product categories from mesopelagic fisheries. D3.8

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