Valorisation of Seafood Side-Streams through the Design of New Holistic Value Chains: WaSeaBi Project

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript presents a nice report containing relevant information about the WaSeaBi project. The article addresses a relevant subject and shade light on important aspects of side-streams from fisheries and aquaculture industries. Some points should be revised before publication.

Lines 73-75. Please revise. Composition of some side-streams (e.g. bones, scales) are not necessarily similar to the fillet.

Lines 105-108. Selection criteria for side-streams is unclear. The term “comprehensive analysis” is too broad and unspecific. Criteria are not detailed in Title 2 (Description) or Title 3 (Project).

Line 122. It is unclear if animal feed mentioned here would include ingredients/supplements for aquaculture as well.

Line 173. The number of responding companies for each case is missing. This relevant information should be included in the manuscript.

Lines 203 and 217. Microbial load is not provided in either Table 1 or Table 2 as mentioned in the text.

Lines 225-231. A large variation in composition is quite expected for this type of raw materials. Thus, the number of samples/batches evaluated should be indicated in Tables 1 and 2.

Tables 1 and 2. More than “composition” these tables present a “chemical characterization”.

Title 4.1. Optimizing by cooling is not addressed under this title. Please check.

Title 4.2.1. The pH-shift process has been extensively investigated for protein extraction from different sources, including by-products from fisheries and aquaculture industries. The literature is plenty of information. A clear description of how this project provides an advance in this topic is missing.

Lines 340-344. Processing conditions should be adapted depending on season and species/type of side-stream. This result seems a drawback and therefore an insight about how difficult are the adjustments needed should be provided.

Title 4.2.2. The importance of choosing flocculants to control processing costs is duly mentioned. In this case, would not isoelectric protein precipitation provide better recovery than Levasil (51-51% recovery)?

Title 4.2.3. Would process waters from production of salted cod be a good side-stream for membranes processing? Suitable membranes could selectively retain proteins and peptides.

Title 4.2.4. Enzymatic hydrolysis of fish by-products has been extensively investigated and obtaining bioactive hydrolysates is a quite expected result. Antioxidant and antihypertensive (ACE-inhibitory) activities have been observed in countless studies. The results described in the manuscript (lines 431-459) are not impressive, as biological activities were observed at relatively high concentrations, as previously described in many studies. The lack of significant advances in obtaining bioactive hydrolysates should be mentioned and this part can be significantly reduced. Focus should be done on how the hydrolysis process could be improved for major side-streams.

Title 4.3. Drawbacks and limitations/difficulties to scale up were not pointed out. Moreover, some metrics about technical performance are missing in Table 3, as only generic descriptions are presented.

Table 4. When mentioning the challenges of enzymatic hydrolysis, it should read “enzyme production has a high environmental impact”.

Lines 526-538. Emphasize the problem of fossil fuel-based electricity. As green alternatives to generate electricity are already available, space for fossil fuels should be restricted when pursuing true sustainability.

 

Comments on the Quality of English Language

The manuscript is generally well written.

Author Response

Thanks for the constructive comments we have responded to them in the attached file. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The increasing demand for seafood has led to the generation of significant amounts of side-streams, which are often considered waste despite their potential value in terms of protein, fatty acids, and minerals. The WaSeaBi project, which is supported by the European Union under the Horizon 2020 BBI JU initiative, aims to tackle this issue by promoting the sustainable and economically viable utilization of these side-streams. This effort not only contributes to improved food security but also plays a role in environmental conservation. This project focuses on developing innovative technologies and methodologies to efficiently convert seafood side-streams into marketable products, such as protein-based food ingredients, bioactive peptides, and mineral supplements. The goal is to turn what is currently perceived as waste into valuable resources. The WaSeaBi project began with a comprehensive analysis to identify the challenges hindering the efficient utilization of side-streams. This involved conducting a thorough study of the European seafood industry to gain insights into the existing obstacles. The primary issues identified included technological limitations, lack of space and personnel, and a limited market for the resulting products. The WaSeaBi project aims to transform the way side-streams from the fisheries sector are viewed and utilized, with the ultimate goal of creating a more sustainable and efficient seafood industry that minimizes waste and maximizes the value of its by-products. This project explored a range of laboratory-scale technologies, including pH-shift, enzymatic hydrolysis, membrane concentration, and flocculation with centrifugation, with the aim of extracting valuable components from the side-streams. Subsequently, this project scaled up and tested these technologies on a pilot scale to assess their potential for industrial application. For instance, the membrane concentration technology proved to be effective in recovering valuable molecules from mussel cooking side-streams, simultaneously reducing the environmental impact of the extraction process. Flocculation was instrumental in recovering proteins and phosphates from process waters, playing a crucial role in reducing the organic load of effluents. Furthermore, this project developed decision-making tools to aid in selecting and implementing the most appropriate valorization strategies, considering technical, legal, economic, and environmental aspects. To evaluate environmental sustainability, this project conducted a Life Cycle Assessment, which identified the key factors contributing to the environmental impact of each technology. The findings underscored the importance of reducing chemical consumption and improving energy efficiency for optimizing the environmental performance of the valorization technologies.

The WaSeaBi project charts a promising course toward the sustainable and economically advantageous utilization of seafood side-streams. Using innovative technologies, the project not only helps to diminish waste and environmental impact but also enables the conversion of low-value side-streams into high-value products. Furthermore, it offers a structured framework to assist industry stakeholders in making well-informed decisions regarding the valorization of secondary streams. This initiative represents a significant stride toward a more sustainable and economically viable fisheries and aquaculture industry, establishing a precedent for future projects aimed at surmounting technological and infrastructural barriers to the valorization of seafood side-streams.

While the report primarily focuses on researching and analyzing the industrial situation in Europe, the research methods and content hold significant reference value for other regions across the globe. It is recommended to publish the report in its current state to benefit a wider audience beyond the European context.

Author Response

We thank the reviewer for the nice comments, which are highly appreciated. Since there were no wishes for changes we have not uploaded any file with detailed responses. 

Reviewer 3 Report

Comments and Suggestions for Authors

 

The study assumes a growing demand in the fisheries sector, which leads to the generation of by-products that are transformed into waste, which, due to their composition, represent a potential protein value. The EU-funded WaSeaBi project addresses this and proposes sustainable utilization on the basis of an economically viable approach, which is conducive to improving food safety and environmental conservation. The objective was to study the development of innovative technologies and methodologies and to achieve an efficient valorization of this type of seafood waste into products that can be marketed as food ingredients based on their properties. The project focused on analyzing the obstacles in the utilization of these wastes. The European seafood industry was included in the study, which incorporated challenges like technological, personnel and space deficiencies and a limited market for seafood products. Technologies were examined in the laboratory in order to extract value components from the waste and then tested at a pilot scale. They propose tools for better decision-making in the selection and construction of value strategies under technical, legal, economic and environmental aspects. The results regarding environmental sustainability indicate a significant reduction in chemicals and improvement in energy efficiency. The study presents a promising pathway for the sustainable and economically profitable utilization of these seafood by-products. It means a reduction of waste and environmental impact, together with the generation of high-value products. They propose an information platform for stakeholders in the sector, an economically viable and sustainable alternative, and submit to continue with this type of study in the future in order to overcome all kinds of barriers. In the introduction, the importance of these wastes in seafood production and the great usefulness of these wastes for food production and the environment are discussed. A description of the project, the objectives and the characterization of selected seafood side-streams are presented. The results are integrated with existing optimization to utilize fish side streams, detailing the valorization technologies used and the technologies used at the pilot scale. Finally, it points strongly to the benefit of improving the sustainability and profitability of the fish industry by valuing these side streams of these products. In particular, they highlight the importance of the process species and the selection of side stream fractions aimed at optimizing the pH change method. The 646 WaSeaBi project focuses on the valorization of side streams and, at the same time, offers a structural framework to all interested parties. This paper is very precisely formulated, analyzed and developed. Furthermore, the objectives and analysis are supported by recent and essential literature. Therefore, it is recommended for publication.

Author Response

We thank the reviewer for the nice comments, which are highly appreciated. Since there were no wishes for changes we have not uploaded any file with detailed responses. 

Reviewer 4 Report

Comments and Suggestions for Authors

The authors reported that the valorization of seafood side-streams may improve the sustainability and profitability of the global fisheries and aquaculture industry. As a project report, this paper provided enough information of their findings, which have the potential to influence the proceeding of the related areas. Before consideration for publication, some issues should be conducted.

1. Too many sentences were applied in the abstract section. Only the crucial and important findings and the effects should be presented. Please shorten the abstract section.

2. I suggested that the presentation of “2. Project Overview” can be shown in a figure or scheme, which made this part more understandable and clearer.

3. Table 3 and Table 4 contained a lot of sentences to describe the findings, however, this kind of presentation is not very helpful for the readers to understand the authors’ findings and intentions. Please reorganize this part.

4. Please check and unify the format of references based on the journal guidelines.

Author Response

We thank the reviewer for the constructive comments, which we have addressed in the attached file. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The major points raised in the first round of review were properly addressed. The manuscript was improved and merits publication.