Comparative Assessment of Insect Processing Technologies for Sustainable Insect Protein Production

Round 1

Reviewer 1 Report

The work proposes the study of LCA for various technologies and processes for insect production.

The paper is well organised and has no major weaknesses, the wording is clear and precise.

Check in l58 the word is freezing or freezedrying?

Check the scale of the graphs in figures 3 and 4, is a maximum of 110 and a minimum of -10 really relevant or is it just the effect of autoscaling?

In l308 use subindices in CO₂

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Title:

ok.

Abstract:

·         Consider briefly discussing the significance of the findings in relation to the insect protein production industry or the broader field of sustainable protein sources.

·         Conclude the abstract with a strong statement summarizing the key implications of the study and the potential impact of the research findings

Introduction

Clarification and Expansion:

In lines 26-27, specify the specific reasons why insects are considered promising, such as their nutritional value, growth efficiency, and potential to alleviate food insecurity.

When mentioning traditional livestock farming practices involving vertebrates (lines 29-30), briefly mention the environmental concerns associated with these practices to highlight the need for more sustainable alternatives.

Clarity:

In lines 31-33, clarify what aspects of the European and North American markets have led to increased demand for insect-based products. Is it due to sustainability concerns, changing dietary preferences, or other factors?

Specify the significance of the increase in demand for products based on insects (line 33), either in terms of market size or environmental impact.

Specificity:

When introducing insect species (lines 35-37), briefly explain why these particular species have been chosen and how their characteristics relate to their use as protein sources.

Process Details:

Provide more details about why defatting is important due to the high-fat content of insects (lines 59-60). Explain how high-fat content might impact the usability of insect-derived ingredients in various applications.

Justification for Inclusion:

 

In lines 76-80, explain why it's important to explore the collective application of sacrifice, drying, and defatting processes as successive operations in the production process. Why does this gap in research matter, and how might it impact the insect protein industry?

Research Gap and Contribution:

Emphasize more explicitly how your study fills the gap mentioned in lines 77-80. Explain how your research is unique in considering the interconnectedness of these processes and how it contributes to the field.

Clear Objectives:

Clearly state the main goals of the study in a separate sentence (lines 89-92) to ensure readers fully understand what the study aims to achieve. Specify that the comparison includes freezing, lyophilization, and SFE with CO2.

Materials and Methods

Processing Treatments:

·         Provide a clearer transition between the introductory sentences and the specific details of the processing treatments. Start by explaining the importance of investigating these treatments.

·         Consider using bullet points or a numbered list to present the various processing technologies for sacrifice, drying, and defatting.

·         Use subheadings for each technology (e.g., "Sacrifice Methods," "Drying Methods," "Defatting Methods") to further organize the content.

Goal and Scope:

In lines 121-125, provide a stronger rationale for why this particular goal was chosen. Explain why quantifying environmental impacts and comparing traditional and alternative processing methods is crucial for the industry.

Functional Unit and System Boundaries:

Clarify the choice of 1 kg of insect protein as the functional unit (FU) and its significance in making comparisons. Explain why it's representative of the study's objectives.

In lines 134-156, consider using bullet points or a numbered list to clearly present the different stages and processes included in the "cradle-to-gate" LCA scope.

Elaborate briefly on why these stages were included and why others were excluded from the analysis.

Allocation:

Explain in more detail the basis for the allocation factors used in the study (lines 158-163). Clarify how these factors were determined and their implications for the results.

Software and Methodology:

- Provide a brief overview of the Sphera LCA software and the Environmental Footprint (EF) methodology in terms of their role in the analysis and their relevance to the study's objectives.

Results:

Clarification of Objectives:

·         In the introductory sentence, clarify what kind of results are being presented. Are these results focused on the environmental impact assessment of the different processing methods?

 Impact Categories Contribution Analysis:

In lines 213-215, consider rephrasing for clarity: "Based on the normalized and weighted results, the most relevant impact category was identified as land use, contributing..."

Instead of saying "the most relevant impact category," you could specify the category that was most prominent in each treatment.

Provide a brief explanation of what each impact category represents (e.g., land use, energy use) to help readers understand their significance.

In lines 222-245, the discussion of processes contribution is comprehensive, but it could be more reader-friendly. You could break down the paragraph into smaller, focused paragraphs that discuss each impact category separately for better clarity.

 Results Comparison:

Provide a brief summary at the end of this section that outlines the overarching findings of the comparison. For instance, which processing treatment demonstrated the best environmental performance overall, and which one showed the least favorable results.

Discussion:

·         Add more recent references to defend or to show opposite results.

·         In the opening sentences, provide a concise summary of the objectives of the study and the main findings.

·         In the discussion of process contributions (lines 292-302), emphasize why corn and wheat cultivation, collection, and processing emerged as significant processes, especially in relation to the observed impact categories. For instance, how do these processes contribute to land use and other categories?

·         In lines 300-302, when discussing the importance of transitioning to renewable energy sources, elaborate on the potential benefits and challenges associated with this transition in the context of insect protein production. Discuss how such a transition could lead to reduced environmental burdens and offer long-term sustainability benefits.

·         In the discussion of the comparison results (lines 304-318), provide more detailed insights into the factors that led to the varying environmental impacts among the processing treatments. For instance, why does the BOS treatment show higher impacts? What aspects of the SFE extraction process contribute to its high energy demand?

·         Further elaborate on the implications of the study's findings for the development of sustainable insect value chains. How can these findings guide decision-makers, stakeholders, and researchers in choosing environmentally friendly processing methods and optimizing the overall insect production process?

·         In your concluding sentences (lines 320-323), summarize the key takeaways from the study. Emphasize the contribution of this research to the understanding of environmental impacts in insect protein production and processing. Consider mentioning future research directions or potential implications for the broader field of sustainable protein production.

General comments

 After carefully reviewing the manuscript, I must commend the author for their skillful writing and overall presentation. However, I have identified several areas where the manuscript could be improved. These suggestions are intended to help the author further enhance the manuscript's readability, structure, and impact.

Maintain a consistent tense throughout the introduction to improve readability.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The work is interesting, because the aim of the work is to reduce the environmental impact. However, the consumption of insects as an alternative source of protein is of great importance and biotechnological interest. Therefore, the sustainable production of insect protein is emerging from a nutritional and environmental demand, due to the fact that sometimes some insects tend to emerge as pests and impact on various crops.

The following questions arise:

What impact does the type of processing and slaughtering present on protein content and quality?

Is protein digestibility modified during processing?

Is there evidence of amino acid profile in the sample under study?

In some insects, 8 of the essential amino acids are present. In the case of the study sample, is there any change?

The decrease of environmental impact and the increase of protein content play an important role as an alternative for obtaining protein.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

 

The manuscript entitled “Comparative Assessment of Insect Processing Technologies for Sustainable Insect Protein Production” brings some interesting information about the environmental impacts of different processing strategies for the production of insect-derived protein using life cycle assessment.

 

Minor comments:

In the Introduction section (lines 81-82): “In short, there are diverse main challenges of insect processing to be addressed: i) the development of efficient, ii) environmentally friendly and iii) cost-competitive” processes? The phrase above is incomplete. Please revise it.

Figure 3 should have A and B in each part of the figure to improve clarity. The y axys should not displace negative values. Please revise it. Same for Figure 4.

 

Major comments:

Since hexane is the most cost-effective method, why did the authors not use this method as a reference? instead of hot pressing for comparison with SFE extraction using CO2? Please explain.

 

A comparison of the environmental impact of plant-based protein production vs insect-based is critical to consolidate the information stated by the authors in the introduction regarding the enrimental friendliness of insect proteins.

 

 

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

All the suggestions are accepted by the authors. 

Careful proofreading is required. 

Reviewer 3 Report

No comments