Repurposing Hazelnut Waste Products for a Sustainable Economy: A Metabolomic Analysis of Cuticles and Shells to Highlight Their Antioxidant Potential and Inhibitory Activity against Verocytotoxic Escherichia coli

Round 1

Reviewer 1 Report

-The extraction process has not followed correctly.

-Antimicrobial potentials were not evaluated correctly.

-No preliminary antimicrobial activity tests, such as disc diffusion or well diffusion method, were done; this is crucial.

-Neither MIC nor MBC were performed.

-Antimicrobial section is very poorly performed.

-It is useless to assess antimicrobial activity against a single test organism. Minimum of 10 to 20 test organisms must be used.

-Without antimicrobial activity photographs, it is difficult to determine whether or not these substances possess antimicrobial activity.

-This section is rather lengthy; please condense it. It must be constrained and result oriented.

Author Response

Thank you for all your observation.

Firstly, as you suggested, we had the article revised for the English language.

Then, in order to satisfy your main requests regarding the evaluation of antimicrobial activity, we decided to change the title and better specify the approach used, highlighting that our work involved the evaluation of growth inhibition of a verocytotoxic strain of Escherichia coli. In any case, the evaluation of growth inhibition is only part of the work in the manuscript, which focuses on the evaluation of food industry waste products in accordance with circular economy principles. In particular, attention has been focused on the important role of bioactive compounds in cuticles and shells of hazelnuts that give them important functional properties. Due to these, the use of these waste products could be of strong interest in both animal and human nutrition where new natural foods are needed in order to confer food more functional properties and also able to increase product shelf life.

Please see the attachment for the point-by-point response 

Author Response File: Author Response.pdf

Reviewer 2 Report

Manuscript ID: sustainability-2147525

Type of manuscript: Article

Title: Antioxidant and antimicrobial potential of hazelnut waste

Authors: Sara Frazzini, Antonio Zuorro, Sara Panseri, Radmila Pavlovic,

Carlo Angelo Sgoifo Rossi, Luciana Rossi

This article focused on evaluating the functional properties, such as antioxidant and antibacterial capacities of the components of waste products obtained from hazelnuts, especially the cuticle and shell. The results obtained in this article demonstrate the high potential of hazelnut-derived waste products, particularly cuticles, highlighting the importance of their possible use in a circular and sustainable economy.

The article is well-organized, interesting, and clearly written. Considering the growing need to maximize the use of natural resources, this article has a significant benefit because it emphasizes the importance of waste products from hazelnuts. I suggest its publication in its present form. Replace only chapter 3.1. in 3.2., line 263.

Author Response

Thank you for your positive consideration of our work. Concerning your suggestion, we have provided to replace chapter 3.1 in 3.2 as suggested

Reviewer 3 Report

Dear author,

Congratulations on the idea, methods used, sound design, strong statistics, proper English and structure, interesting results in connection with the aim and test presented in detail, good discussion groups, recent literature cited, and the opportunity for future studies to be made in this area of work.

Author Response

Thank you for your positive consideration of our work

Reviewer 4 Report

The manuscript is connected with one of the preliminary concepts connected with the growing importance of agri-food industry waste products in the sustainable circular economy. The focus of the study is on evaluating the functional components of waste products derived from hazelnuts, particularly cuticles and shells. The applied methods are properly chosen and used. The results obtained in this study demonstrated the high potential of hazelnut-derived waste products, highlighting the importance of their possible use in a circular economy.

But where exactly is not clear? It will be interesting the authors to add some examples showing the use of the products

Author Response

Thank you for the suggestion, we have added some examples of the possible use of waste products within the conclusion section (line 383)

Round 2

Reviewer 1 Report

1. The antimicrobial test was not conducted using a standard procedure. 

2. You must dry the extracts and then dilute them to different concentrations, such as 100 mg/ml, 50 mg/ml, and 25 mg/ml, or you must utilize at least one fixed concentration, such as 100 mg/ml.

3. Antimicrobial activity of diluted samples must be evaluated using the disc-diffusion technique or well-diffusion method, or tube method.

4. All the results must be compared with a negative control.

5. Utilizing a single test organism is not problematic. However, the method and results must be standardized.

6. The used methodology is inadequate. It does not properly represent the antibacterial activity of the extracts.

7. Your antimicrobial findings will only be valid if you utilize MIC and MBC.

8. All findings must be repeated thrice.

9. Statistical analysis must be done through ANOVA or independent samples T-test to show the significance of the result. 

10. Images of the zone of inhibition must be provided for antibacterial activity.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 3

Reviewer 1 Report

The manuscript has substantially improved, although extensive English editing is still required.

Author Response

Dear review,

As you suggested, we had the manuscript revised for the English language.

Please find attached a certificate that confirms that the paper has been edited by a professional English language editing agency. Adrian Wallwork, who edited the paper for us, is happy for you to contact him via email if you need any further verification that from a language point of view the paper is ready for publication.

Author Response File: Author Response.pdf

Round 4

Reviewer 1 Report

The manuscript has substantially improved, although extensive English editing is still required.

Paper can be accepted after english editing.

Author Response

Dear review,

As you suggested, we had the manuscript revised for the English language. 

Please find attached a certificate that confirms that the paper has been edited by a professional English language editing agency. Adrian Wallwork, who edited the paper for us, is happy for you to contact him via email if you need any further verification that from a language point of view the paper is ready for publication.

Author Response File: Author Response.pdf