Hopp til hovedinnholdet

Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2022

To document

Abstract

Phycoerythrin (PE) is a photosensitive red pigment from phycobiliprotein family predominantly present in the red algae. The concentration of PE depends on photon flux density (PFD) and the quality of light absorbed by the algae tissue. This necessitates robust techniques to extract PE from the embedded cell-wall matrix of the algal frond. Similarly, PE is sensitive to various factors which influence its stability and purity of PE. The PE is extracted from Red algae through different extraction techniques. This review explores an integrative approach of fractionating PE for the scaling-up process and commercialization. The mechanism for stabilizing PE pigment in food was critically evaluated for further retaining this pigment within the food system. The challenges and possibilities of employing efficient extraction for industrial adoption are meticulously estimated. The techniques involved in the sustainable way of extracting PE pigments improved at a laboratory scale in the past decade. Although, the complexity of industrial-scale biorefining was found to be a bottleneck. The extraction of PE using benign chemicals would be safe for food applications to promote health benefits. The precise selection of encapsulation technique with enhanced sensitivity and selectivity of the membrane would bring better stability of PE in the food matrix.

To document

Abstract

There is an increasing need in the aquaculture industry for more sustainable and functional feed concepts for marine finfish. This study provides results for the effect of alternative feed formulations on health status, welfare parameters, sensory analysis, and growth performance in European seabass (Dicentrarchus labrax) over an 83-day feeding trial. Fish were fed twice a day with five experimental diets. A control diet (control) and four different alternative feed concepts rich in processed animal proteins (PAP), other alternative ingredients (NOPAP), and a positive (NOPAP+) and negative (PAP−) formulation were tested. All alternative formulations contained hydrolysates from aquaculture by-products and macroalgae. The results indicate that the alternative feed concepts are more sustainable alternatives compared with the commercial diet. Equally interesting, the alternative formulations did not affect the sensory analysis of the fillet quality or the animal welfare. These are increasingly important factors in aquaculture products and, accordingly, also in the formulation of new feeds. Feed concepts that are not only more sustainable in their production, have shorter transportation distances, recycle the resources (usage of by-products), and have no adverse effect on growth or welfare parameters are highly needed. Therefore, the experimental diets tested in this study are a win-win concept for future seabass aquaculture production.

To document

Abstract

The hypothesis of the present study was that increased growth in spring, stimulated by increasing temperature and daylength, leads to oxidative stress in Atlantic salmon with accumulation of oxidation products in the tissues and increased utilization of antioxidants. The drop in fillet pigmentation and astaxanthin, often observed in spring by the industry, could be explained by oxidative stress. Furthermore, oxidative stress may cause production related diseases such as development of cataracts and melanin spots in the fillet. We sampled Atlantic salmon from two cages in a commercial scale experiment in Northern Norway (67°N), every month from April until August and then every second month until December (510 ± 160–3060 ± 510 g, mean weight ± std). The specific growth rate (SGR) increased with increasing temperature until midsummer and decreased thereafter. We found that vitamin E in the fillet and vitamin C in the liver were depleted in the spring and were restored in the autumn, even though the dietary concentrations were stable. Astaxanthin concentration in the muscle was constant during the spring and summer and increased in the autumn, concomitant with an increase in astaxanthin supplementation. Cataract increased from zero in May until July, when 90% of the fish were affected. The glutathione based redox-potential in the lenses became more reduced from June, indicating a protective mechanism against oxidative stress and cataract. The number of fish with melanin spots was high in June and decreased in August and October, but the size and intensity of the remaining spots increased in the same period. The change in vitamin C and E concentrations, cataract and glutathione metabolism during spring and early summer, indicate that the fish became oxidized in this period, while malon-di-aldehyde (MDA) and astaxanthin concentrations did not support the hypothesis. There are too few data to draw conclusions on possible effects of oxidative stress on melanin spots.

To document

Abstract

One part of aquaculture sustainability is reducing the environmental footprint of aquaculture feeds. For European aquaculture, this means finding feed ingredients that are produced within the economic community, and that are not in conflict with human consumption. This is especially challenging when formulating diets for carnivorous fish such as turbot with low tolerance to fishmeal replacement that are both nutritious and economically and environmentally sustainable. Therefore, we investigated the effects of two novel and innovative feed formulation concepts on growth and feed performance and the nutritional status of market-sized turbot in a recirculating aquaculture system. In a 16-week feeding trial, 440 turbot (300 ± 9 g) were fed twice a day with a control diet (CTRL), based on a commercial formulation, and four experimental diets. The experimental diets were designed to investigate the effects of two formulations concepts based on sustainable terrestrial plant proteins (NoPAP) or processed animal proteins (PAP) and of 30% and 60% fishmeal replacement with emerging feed ingredients (fisheries by-products, insect meal and fermentation biomass). Turbot from the CTRL group had a similar growth and feed performance than fish fed the NoPAP30 formulation, with a significant decline of performance in the fish fed both PAP formulations and the NoPAP60. Comparing the two formulation concepts with each other the voluntary feed intake and protein efficiency ratio on tank basis as well as the individual weight gain and relative growth rate was significantly higher in the fish from the NoPAP groups than PAP groups. Furthermore, the apparent digestibility of nutrients and minerals was significantly reduced in the fish fed with the diets with 30% and 60% fishmeal replacement level compared to the fish from the CTRL group. In conclusion, the performance of the fish fed the NoPAP30 formulation concept highlights the potential of the used combination of sustainable ingredients, such as fisheries by-products, insect meal, microbial biomass and plant protein for turbot. Furthermore, this study shows that turbot has a higher tolerance to the incorporation of plant and insect protein than of processed animal protein.

To document

Abstract

Two Life-Cycle Assessments (LCAs) were conducted to evaluate the environmental performances of selected novel eco-intensification innovations for the treatment and valorisation of sludge and fish mortalities from finfish aquaculture. The first innovation is based on a new process for filtering and drying particles from the reject water from a Recirculating Aquaculture System (RAS), with end-of-life recovery of nutrients and biomass to be reused as organic fertiliser or as energy source. The second process is based on a new device for drying fish mortalities and reusing the end-product as ingredient in the pet food industry or as energy source. Innovations refer to a functional unit of 1 ton of farmed fish and of fish mortalities, respectively, and were tested with a RAS for smolt production within the physical system boundary of a Norwegian facility. A set of standard indicators was selected for the Life-Cycle Impact Assessment (LCIA). The results indicate that the new processes compare well with the established ones, showing a marked decrease in most impact categories: indicators decrease by −12% through to −67% when sludge treatment innovations are applied, and by more than −86% after novel changes about fish mortality, with water consumption instead increasing by +7% and up to +50%, respectively. Furthermore, the analysis provided insights which could lead to improve their environmental performances.

To document

Abstract

In Europe, turbot aquaculture has a high potential for sustainable production, but the low tolerance to fishmeal replacement in the diet represents a big issue. Therefore, this study investigated the effects of more sustainable feed formulations on growth and feed performance, as well as nutritional status of juvenile turbot in recirculating aquaculture systems. In a 16-week feeding trial with 20 g juvenile turbot, one control diet containing traditional fishmeal, fish oil and soy products and two experimental diets where 20% of the fishmeal was replaced either with processed animal proteins (PAP) or with terrestrial plant proteins (PLANT) were tested. Irrespective of diets, growth performance was similar between groups, whereas the feed performance was significantly reduced in fish of the PAP group compared to the control. Comparing growth, feed utilisation and biochemical parameters, the results indicate that the fish fed on PAP diet had the lowest performance. Fish fed the PLANT diet had similar feed utilisation compared to the control, whereas parameters of the nutritional status, such as condition factor, hepato-somatic index and glycogen content showed reduced levels after 16 weeks. These effects in biochemical parameters are within the physiological range and therefore not the cause of negative performance. Since growth was unaffected, the lower feed performance of fish that were fed the PAP formulation might be balanced by the cost efficient formulation in comparison to the commercial and the PLANT formulations. Present study highlights the suitability of alternative food formulation for farmed fish.

To document

Abstract

Chitin is one of the most diverse and naturally occurring biopolymers, and it is mainly present in crustaceans, insects, and fungi. Chitosan is derived from chitin by deacetylation process. It is important to note that the conventional chemical method of extracting chitin includes disadvantages and it poses various environmental issues. Recently, the green extraction techniques have perceived substantial development in the field of polymer chemistry. A variety of methods have been successfully developed using green extraction techniques for extracting chitin and chitosan from various resources. It includes the use of ionic liquids (ILs), deep eutectic solvents (DES), microbial fermentation, enzyme-assisted extraction (EAE), microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), subcritical water extraction (SWE), and electrochemical extraction (ECE). In this review, the extraction of chitin and chitosan using greener approaches were summarized. In addition, challenges, opportunities and future perspectives of green extraction methods have also been narrated.

To document

Abstract

Aquaculture industry is one of the major food-producing sectors in the world that provide nutritional food security for mankind. Fish and crustacean farmers are facing various challenges in treating the rapid spread of infectious diseases in recent times. Numerous strategies, including antibiotics, disinfectants, and other antimicrobial agents, have been applied to protect the cultivable aquatic animals from infectious diseases. These applications lead to the development of antimicrobial resistance, toxicity, and the accumulation of antibiotic residues in cells and organelles of the cultivable edible organisms and the environment. The use of naturally derived compounds, polysaccharides, and functional metabolites has gained immense attention among aquaculturists. Mushrooms and their nutraceutical components have been widely used in various sectors, including food, pharmaceutical, poultry, and aquaculture industries, for their non-toxic and eco-friendly properties. To date, there are several reports available on edible and medicinal mushrooms as a dietary ingredient for fish and decapod crustacean culture. The mushroom products such as mycelia, stalk, dry powder, polysaccharides, and extracts have been utilized in aquaculture as growth promoters and immunostimulants, improving the digestive enzyme activity, antimicrobials, and improving the health status of cultivable aquatic animals. This present review elucidates the effectiveness of mushrooms and mushroom-derived compounds as prebiotics in aquaculture. The challenges and future perspectives of mushroom-derived bioactive molecules have been discussed in this review.

To document

Abstract

Aquaculture industry is one of the world’s fastest and largest growing food producing sector. Most importantly, the usage of fish meal in aquaculture has been replaced with alternate protein sources due to their production cost, demand of raw materials and various environmental issues. The insect black soldier fly (Hermetia illucens) larval (BSFL) meal is being recognized as a feed ingredient in aquafeeds for their protein rich content similar to fish meal (FM). BSFL meal has been utilized as a fish meal or soy meal substitution in aquaculture to improve the nutrition. The culture of H. illucens larvae can be achieved using various biodegradable wastes and converted into a valuable biomass. In addition, the proximate analysis of H. illucens has been analyzed for its multifaceted role in poultry, cattle feed preparation and human consumption. The effectiveness of BSFL diet was analyzed for final body weight (FBW), specific growth rate (SGR), feed conversion ratio (FCR), feed intake (FI), feed efficiency (FE) and survival (SUR) of different fish and shrimp used as an experimental models with FM as the control diet. However, there is no comprehensive review available on the BSFL as an alternate protein source in aquaculture till date. Hence, the present review aimed to evaluate the feasible role of BSFL in feed, its sustainable production and challenges of BSFL meal in aquaculture sector along with their merits and demerits.

To document

Abstract

Phototrophic microalgae use light to produce biomass and high-value compounds, such as pigments and polyunsaturated fatty acids (PUFA), for food and feed. These biomolecules can be induced by flashing light during the final growth stage. We tested different exposure times (1–6 days) of flashing light (f = 0.5, 5, 50 Hz; duty cycle = 0.05) on biomass, pigment and fatty acid productivity in Diacronema lutheri and Tetraselmis striata. A three-day exposure to low-frequency (5 Hz) flashing light successfully increased the production of fucoxanthin, diatoxanthin, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in D. lutheri up to 4.6-fold and of lutein, zeaxanthin and EPA in T. striata up to 1.3-fold compared to that of continuous light. Biomass productivity declined 2-fold for D. lutheri and remained similar for T. striata compared to that of continuous light. Thus, short-term treatments of flashing light may be promising for industrial algal production to increase biomass value.