PEER REVIEWED ARTICLES
Fishmeal, plant protein and fish oil substitution with single cell ingredients in organic feeds for European sea bass (Dicentrarchus labrax)
Antigoni Vasilaki, Elena Mente, Eleni Fountoulaki, Morgane Henry, Chrysanthi Nikoloudaki, Panagiotis Berillis, Katerina Kousoulaki and Ioannis Nengas
Abstract
Single cell ingredients (SCI) are considered promising nutrient sources which are produced using environmentally friendly biotechnological processes. The aim of the current study was the evaluation of replacing fishmeal, plant protein sources and fish oil by single cell ingredients in organic feeds for European sea bass (Dicentrarchus labrax). Bacterial protein, yeast protein and microalgae were used to replace fishmeal trimmings, soya bean meal and fish oil from trimmings. Triplicate groups (30 fish per replicate) of European sea bass (14.4 ± 2.4g) fed the experimental diets for 71 days. Results showed that incorporation of SCI at all levels of inclusion significantly enhanced nutrient digestibility. Additionally, growth performance parameters were not affected by SCI inclusion, exhibiting similar or improved values. Moreover, a tendency for improved anterior and posterior gut structure was observed and a significant increase of lysozyme activity at the two highest inclusion levels of SCI was determined. Overall the results showed that inclusion of single cell ingredients at 15% (bacterial: yeast: algae – 9.4: 4.7: 1) is possible without compromising any of the parameter evaluated. According to these findings a higher substitution of fishmeal trimmings, plant protein sources and fish oil from trimmings can be further evaluated, in future studies, by single cell ingredients in organic diets for European sea bass (Dicentrarchus labrax).
Published in: Front. Physiol., Sec. Aquatic Physiology
Volume 14, 2023
Evaluation of physical and instrumentally determined sensory attributes of Atlantic salmon portions packaged in modified atmosphere and vacuum skin
Sherry Stephanie Chan, Maren Skare, Bjørn Tore Rotabakk, Morten Sivertsvik, Jørgen Lerfall, Trond Løvdal, Bjørn Roth
Abstract
Fresh Atlantic salmon (Salmo salar) were slaughtered and stored on ice at 0 °C then portioned and packaged six to eight days later in modified atmosphere (CO2:N2 60:40) packaging (MAP), vacuum skin packaging and open air. All fillet portions were stored in refrigerated conditions at 4 °C. Physical and instrumentally determined sensory quality parameters, including water holding properties, pH, colour, texture and microbiological shelf life, were examined for three weeks. The results showed that both MAP and vacuum skin packaging gave comparable quality in drip loss, water holding capacity, texture and microbiological shelf life. Both packaging groups displayed increased lightness and decreased redness and yellowness throughout storage after filleting. Fillets kept in MAP had consistently lower pH with a darker, more reddish, and yellowish colour than skin packaged fillets. Fillets stored in air had the shortest microbiological shelf life (<13 days) even when they were portioned later. It is concluded that the microbiological shelf life of MAP and skin packaged fillets at 4 °C was around 18–20 days with a limit of 106 cfu/g and therefore effectively extends the microbiological shelf life of raw fillets by 1.5 times.
Published in: Lebensmittel-Wissenschaft und-Technologie, ISSN 2405-8440
Volume 146, July 2021, Page 111404
Publisher: Academic Press
Atlantic Salmon (Salmo salar) Performance Fed Low Trophic Ingredients in a Fish Meal and Fish Oil Free Diet
K. Kousoulaki, L. Sveen, F. Norén and Å. Espmark
Abstract
To evolve fish farming in an eco-efficient way, feed production must become less dependent on forage fish-based ingredients and make more use of low trophic level organisms, including microalgae, higher plants, as filter feeding organisms and other ingredients with low competition to established food value chains. Diets nearly free of fish meal and fish oil are not a novelty but are often composed of complex mixtures, containing supplements to meet the farmed animal’s nutritional requirements. Sustaining a growing aquaculture production, maintaining at the same time fish health, welfare, and profitability, and meeting strict environmental and food safety demands, is challenging and requires new technologies, great investments, and more knowledge. A benchmarking feeding trial was performed to demonstrate the main effects of four low trophic raw materials on Atlantic salmon (Salmo salar) growth, metabolism, skin health and fillet quality. To this end, a diet was produced to contain commercially relevant levels of fresh high quality organic FM and FO and was used as a control in the trial (FMFO). Heterotrophically produced Schizochytrium limacinum biomass was used to replace organic FO (HM diet). Spray dried cell wall disrupted biomass of the phototrophically cultured diatom Phaeodactylum tricornutum replaced partly FM and FO (PM diet). Black soldier fly (Hermetia illucens) larvae meal and tunicate (Ciona intestinalis) meal, were used to produce the diets BSFL and TM, respectively, replacing large parts of FM as compared to the FMFO. A fifth test diet was produced combining all test raw materials and removing all FM and FO (0FM0FO diet). All test ingredients were well accepted sustaining high growth rates (TGC values near 4) and feed efficiency (FCR values below 0.9) in salmon showing good gut health and normal metabolic responses. However, none of the treatments reached the growth performance of FMFO. Additional differences between test and control treatments were identified in dietary nutrient apparent digestibility, fish biometrics, blood metabolites and fillet and skin composition. Extensive raw material and dietary chemical characterisation was performed to provide insight on potential shortcomings in the novel low trophic level ingredients which can possibly be overcome combining complementary raw materials.
Published in: Frontiers in Physiology, ISSN 1664-042X
Volume 13, 2022
Publisher: Frontiers Research Foundation
Effective algorithmic operational framework for fish texture evaluation in industry: Achieving maturity
Dimitrios Dimogianopoulos, Kriton Grigorakis
Abstract
Reliable, nondestructive fish freshness evaluation applicable during fish commercialization has been continuously pursued by scientists and industry. Taking into account that fish texture is primarily affected even at early stages of post-mortem storage, a relevant nondestructive testing framework for rapid textural assessment of fish freshness was developed in the past. Herein, an algorithm operating within the aforementioned framework and optimized for use in industrial environments is proposed. Sea bass (Dicentrarchus labrax) both freshly killed and stored on ice for 6 days have been used for comparative testing. The fish is part of a system, which is vibration-tested via a new testing protocol designed for easy implementation and robustness to noise. At the same time, a new closed-form analytical expression for the system response to the specific testing is computed and used along with experimental data, for obtaining specific mechanical (thus muscle-structural) characteristics of fish flesh. This computation is designed to only require readily available routines found in most relevant software. The algorithmic operational framework has been used in two different test setups (a custom-built test rig and a prototype device), with results following remarkably similar trends, clearly discriminating different textural (thus freshness) characteristics, and consequently validating the proposed approach.
Published in: Aquaculture and Fisheries, ISSN 2468-550X
Volume 8, Issue 4, July 2023, Pages 422-430
The combined effect of pulsed electric field treatment and brine salting on changes in the oxidative stability of lipids and proteins and color characteristics of sea bass (Dicentrarchus labrax)
Janna Cropotova, Silvia Tappi, Jessica Genovese, Pietro Rocculi, Marco Dalla Rosa, Turid Rustad
Abstract
A combined effect of pulsed electric field application and salting in a brine with 5 and 10% w/w NaCl on oxidative stability of lipids and proteins, as well as color characteristics of sea bass samples, was assessed in the study. The applied intensity of the current was set at 10 and 20 A corresponding to 300 and 600 V cm−1, respectively. Pulsed electric field (PEF) treatment led to a significant (p < 0.05) increase in primary and secondary lipid oxidation products expressed as peroxide value, conjugated dienes and 2-thiobarbituric acid reactive substances in PEF-treated samples compared to untreated ones. Conjugated dienes, as unstable primary oxidation products, correlated with b∗-value (p < 0.05, R = 0.789), suggesting their contribution to the yellowness of the fish flesh due to fast decomposition and conversion into secondary oxidation products yielding yellow pigmentation. However, none of the fish samples treated at the higher current intensity of 20 A exceeded the acceptable level of 5 meq active oxygen/kg lipid according to the requirements of the Standard for fish oils CODEX STAN 329–2017, suggesting acceptable oxidative status quality of sea bass samples after the treatment. PEF-treated fish samples also showed a significant increase in Schiff bases and total carbonyls on day 5 and day 8 of brine salting compared to non-treated samples, revealing a strong effect of electroporation on protein oxidation. Published in: Heliyon, ISSN 2405-8440 Volume 7, Issue 1, e05947, January 2021 Publisher: Elsevier
Mapping the Energetic Costs of Free-Swimming Gilthead Sea Bream (Sparus aurata), a Key Species in European Marine Aquaculture
Sébastien Alfonso, Walter Zupa, Maria Teresa Spedicato, Giuseppe Lembo and Pierluigi Carbonara
Simple Summary
Assessment of the energetic costs of different living activities is of primary interest among fish biologists. However, assessing energy expenditure in free-swimming fish is challenging owing to the difficulty of performing such measurements in the field. Therefore, the use of implant fish with sensors that transmit signals that serve as a proxy for energy expenditure is a promising method to counter these limitations, allowing remote monitoring in tagged fish. The aim of this study was to correlate the acceleration recorded by the tag with the activities of the red and white muscles and the oxygen consumption rate (MO2), which could serve as a proxy for energy expenditure, in gilthead sea bream (Sparus aurata), a key species in European marine aquaculture. The acceleration recorded by the tag was successfully correlated with MO2. Additionally, through electromyographic analyses, we determined the activities of the red and white muscles, which are indicative of the contributions of aerobic and anaerobic metabolisms during swimming. Finally, the tag implantation did not affect the swimming performance, metabolic traits, and swimming efficiency of the sea bream. By obtaining insights into both aerobic and anaerobic metabolisms, sensor mapping with physiological indicators may be useful for the purposes of aquaculture health/welfare remote monitoring of gilthead sea bream.
Published in: Biology, ISSN 2079-7737
Volume 10, Issue 2, 2021, Page: 1357
Publisher: MDPI
Study of the influence of pulsed electric field pre-treatment on quality parameters of sea bass during brine salting
Cropotova, J., Tappi, S., Genovese, J., Rocculi, P., Laghi, L., Dalla Rosa, M., & Rustad, T.
Absract
Pulsed electric field (PEF), as an emerging technique, has recently gained increased popularity in food processing and preservation. However, applications in the seafood industry are still scarce. In the present study, sea bass samples were subjected to PEF pre-treatment prior to brine salting to verify the possible acceleration of the brining rate, increasing the salt uptake and ensuring the homogeneous salt distribution in the muscle. The applied intensity of the current was set at 10 and 20 A (corresponding to a field strength of 0.3 and 0.6 kV/cm) prior to sea bass salting in brine with 5 and 10% salt concentration, respectively. The results have shown that PEF pretreatment could effectively shorten the brine salting time compared to control samples (from 5 to 2 days), or increase the salt uptake up to 77%, ensuring at the same time its homogenous distribution in the muscle. However, myofibrillar protein solubility was significantly reduced in PEF pretreated samples. At the same time, no significant differences in water holding capacity and water activity between PEF pre-treated and untreated samples were found during the whole salting period. Freezable water was influenced by PEF application, but the effect was significant only at the lowest salt concentration during the first period of the salting process.
Published in: Innovative Food Science & Emerging Technologies, ISSN 1466-8564
Volume 70, June 2021, 102706
Publisher: Elsevier BV
Using Telemetry Sensors Mapping the Energetic Costs in European Sea Bass (Dicentrarchus labrax), as a Tool for Welfare Remote Monitoring in Aquaculture
Sébastien Alfonso, Walter Zupa, Maria Teresa Spedicato, Giuseppe Lembo and Pierluigi Carbonara
Abstract
Physiological real-time monitoring could help to prevent health and welfare issues in farmed fishes. Among physiological features that can be of interest for such purposes, there is the metabolic rate. Its measurement remains, however, difficult to be implemented in the field. Thus, mapping the fish acceleration recorded by tag with the oxygen consumption rate (MO2) could be promising to counter those limitations and to be used as a proxy for energy expenditure in the aquaculture environments. In this study, we investigated the swimming performance (Ucrit) and the swimming efficiency (Uopt, COTmin), and we estimated the metabolic traits (standard and maximum metabolic rates, SMR and MMR, as well the absolute aerobic scope, AS) of European sea bass (Dicentrarchus labrax; n = 90) in swimming tunnel. Among all tested fish, 40 fishes were implanted with an acoustic transmitter to correlate the acceleration recorded by the sensor with the MO2. In this study, the mean SMR, MMR, and AS values displayed by sea bass were 89.8, 579.2, and 489.4 mgO2 kg−1 h−1, respectively. The Uopt and COTmin estimated for sea bass were on average 1.94 km h−1 and 113.91 mgO2 kg−1 h−1, respectively. Overall, implantation of the sensor did not alter fish swimming performance or induced particular stress, able to increase MO2 or decrease swimming efficiency in tagged fish. Finally, acceleration recorded by tag has been successfully correlated with MO2 and fish mass using a sigmoid function (R2 = 0.88). Overall, such results would help for real-time monitoring of European sea bass health or welfare in the aquaculture environment in a framework of precision livestock farming.
Published in: Frontiers in Animal Science, ISSN 2673-6225
Volume 3, 2022
Publisher: Frontiers Media S.A.
The Role of Eco-Labels in Making Environmentally Friendly Choices: An Eye-Tracking Study on Aquaculture Products with Italian Consumers
Authors: Migena Proi, Emilia Cubero Dudinskaya, Simona Naspetti, Emel Ozturk Raffaele Zanoli
Abstract
Eco-labels are crucial in helping consumers make sustainable food choices. However, previous literature has shown that eco-labels lack visibility and, frequently, are not easy for consumers to see. The main goal of the present study was to analyse the influence of aquaculture eco-labels’ visual elements—size and saliency—on consumers’ visual attention and choice. The study uses an eye-tracking methodology, together with a choice experiment and a semiotic analysis. A word association (WA) task was used to explore how each eco-label’s graphic design influenced consumers’ perceptions. Sixty-one consumers’ eye movements were tracked while choosing smoked salmon and seabass products carrying different eco-labels. The results showed that size and saliency largely influence visual attention. The choice of aquaculture products was influenced only by the size of the eco-labels. According to the WA task, the shape, the symbols and the language in which the claim was written influenced consumers’ preferences. The findings contribute to marketing and food research, suggesting which visual elements should be considered to increase consumers’ interest in eco-labels.
Published in: Sustainability
Volume 15, Issue 5, 2023, Page 4659
Publisher: MDPI
The Environmental Impact of Partial Substitution of Fish-Based Feed with Algae- and Insect-Based Feed in Salmon
Authors: Pietro Goglio,Sander Van Den Burg,Katerina Kousoulaki,Maggie Skirtun,Åsa Maria Espmark, Anne Helena Kettunen and Wout Abbink
Abstract
One of the key challenges for aquaculture is to reduce “fishing-for-feed”. Alternative fish feeds need to be environmentally assessed to ensure they are sustainable. The present research consisted of an attributional LCA to (i) estimate the impact on salmon farming of a partially algal–insect-based diet vs a conventional fish meal/fish oil-based diet, (ii) identify the contribution of each process to the environmental impacts of the whole fish farming system, and (iii) identify potential improvements in the algal–insect value chain through sensitivity analysis of various algal–insect production pathways. The study shows that use of algal–insect-based feed resulted in a higher impact for most of the environmental impact categories due to fish feed production, particularly for soybean, insect, and algal meal. This points to the need to optimise production chains for new fish feed ingredients. Algal meal production using sugarcane sugar and optimised technology and insect meal using exhaust heat and renewable electricity would improve the environmental performance of salmon farming systems using insect- and algal-based fish feed. Methodological improvements with regard to system C and N cycle, biodiversity, and plastic use should be explored to inform policy making and support the implementation of sustainable future salmon farming innovations.
Published in: Sustainability
Volume 14, Issue 19, 2022, 12650
Direct Expression of Fluorinated Proteins in Human Cells for 19F In-Cell NMR Spectroscopy
Authors: Lan B. T. Pham, Azzurra Costantino, Letizia Barbieri, Vito Calderone, Enrico Luchinat, and Lucia Banci
Abstract
In-cell NMR spectroscopy is a powerful approach to study protein structure and function in the native cellular environment. It provides precious insights into the folding, maturation, interactions, and ligand binding of important pharmacological targets directly in human cells. However, its widespread application is hampered by the fact that soluble globular proteins often interact with large cellular components, causing severe line broadening in conventional heteronuclear NMR experiments. 19F NMR can overcome this issue, as fluorine atoms incorporated in proteins can be detected by simple background-free 1D NMR spectra. Here, we show that fluorinated amino acids can be easily incorporated in proteins expressed in human cells by employing a medium switch strategy. This straightforward approach allows the incorporation of different fluorinated amino acids in the protein of interest, reaching fluorination efficiencies up to 60%, as confirmed by mass spectrometry and X-ray crystallography. The versatility of the approach is shown by performing 19F in-cell NMR on several proteins, including those that would otherwise be invisible by 1H-15N in-cell NMR. We apply the approach to observe the interaction between an intracellular target, carbonic anhydrase 2, and its inhibitors, and to investigate how the formation of a complex between superoxide dismutase 1 and its chaperone CCS modulates the interaction of the chaperone subunit with the cellular environment.
J. Am. Chem. Soc. 2023, 145, 2, 1389–1399
Publisher: American Chemical Society
Workshop: How outputs from EU projects can upgrade health management in Mediterranean aquaculture
S. Zrnčić, F. Padros, S. Tavornapanich, N. Lorenzen, D. Volpai, I. Mladineo, A.Manfrin, A. Sitjà-Bobadilla, E. Brun
Abstract
Aquaculture of European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata) is an essential activity in the Mediterranean basin. Several EU Horizon 2020 and regional projects are focusing on the improvement of their farming performance. This workshop aimed at displaying, sharing and discussing projects’ achievements among interested colleagues engaged to work with fish diseases. The most innovative research outputs aiming to improve the European mariculture were presented during this workshop, including updates from EU Horizon 2020 projects MedAID, PerformFISH, ParaFishControl, FutureEUAqua and the Italy-Croatia Interreg project AdriAquaNet.
Published in: Bulletin- European Association of Fish Pathologists, ISSN 0108-0288
Volume 41, Issue 5, 2022, Pages: 178–87
Publisher: FRS Marine Lab.
Funded by:
This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 817737
