The Value of Using Green Extraction Techniques to Enhance Polyphenol Content and Antioxidant Activity in Nasturtium officinale Leaves

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The topic is interesting, and the introduction well informs the reader about the purpose of the research conducted.

The extraction process is the main topic of the paper. The extraction procedure should be described in the main document.

Please describe in more detail the individual research procedures. It should also be specified to what equivalents and specifically to what units the results were converted. The HPLC determination procedure should be described in detail - what apparatus, detector, column, flow, gradient injection, standard curves were used.

The statistical analysis in this article is very important. Please describe it in the main document.

Was statistical significance between results calculated in the paper? It is not indicated in the tables.

The conclusions are too general and are just a summary. They should be more specific.

Author Response

The topic is interesting, and the introduction well informs the reader about the purpose of the research conducted.

We would like to thank the reviewer for his/her comments.

The extraction process is the main topic of the paper. The extraction procedure should be described in the main document.

The extraction procedure is now presented in the main document, as suggested.

Please describe in more detail the individual research procedures. It should also be specified to what equivalents and specifically to what units the results were converted. The HPLC determination procedure should be described in detail - what apparatus, detector, column, flow, gradient injection, standard curves were used.

All the individual research procedures are described in more detail in the main document, as recommended.

The statistical analysis in this article is very important. Please describe it in the main document.

The statistical analysis is described in the main document, as suggested.

Was statistical significance between results calculated in the paper? It is not indicated in the tables.

The conclusions are too general and are just a summary. They should be more specific.

The Conclusions section was made more precise, as suggested.

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript assesses the value of using green extraction techniques to enhance polyphenol content and antioxidant activity in Nasturtium officinale leaves.

Please consider the following suggestion:

Please insert a clear aim of the study at the end of the Introduction.

Please insert the Materials and Methods in the main article. I suggest you leave only the figures in the supplementary material.

 

Comments on the Quality of English Language

Minor editing of English language required.

Author Response

This manuscript assesses the value of using green extraction techniques to enhance polyphenol content and antioxidant activity in Nasturtium officinale leaves.

We would like to thank the reviewer for the following suggestions.

Please consider the following suggestion:

Please insert a clear aim of the study at the end of the Introduction.

A clearer aim of the study has been added, as recommended.

Please insert the Materials and Methods in the main article. I suggest you leave only the figures in the supplementary material.

The Materials and Methods are presented in the main article, as suggested.

Comments on the Quality of English Language

Minor editing of English language required.

Our manuscript has been checked by a native English-speaking colleague.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript describes the influence of different extraction processes on composition and antioxidant activity of watercress ethanolic extract. The manuscript is not well organized and needs significant improvement in discussion and scientific soundness. The major issues are:

a) english needs extensive revision

b) introduction is too short and does not provide sufficient data regarding the background,aim and novelty. Include more data relating the different extraction processes, their benefits and disadvantages when they were used for other plant extracts.  What is conventional method for extraction of polyphenols, venefits and disadvantages,and what US and  PEF method offers better, why they are assumed as green merhod for extraction-clarify more

c) line 59-60, the sentence is confusing. Does watercress have polyphenols or no? Why do authors perform extraction of polyphenols from watercress,if they say the absence of polyphenols...

d) materials and method section:

All used cgemicals need to be places in this section,not in supplementary material

Detailled extraction process needs to be written here,not in supplementary material

Detailled process of TPC and antioxidant activities need to be written in experimental part, it is not sufficient to just put a reference.

e) table 1: include variables, i.e extractive parameters for every code sample to be able to follow results

f) discussion related to the influence of different extractive merhods and extraction parameters on watercress extract quality needs to be improved. For example, add more data from literature related to plant extracts and optimal extractive conditions. How much US, ST and PEF single and in combination had efficiency in extraction of polyphenols from plants in literature? Is your proposed extractive merhod better, the same or worse when compare with the literature? How US and PEF are green extraction methods and why, in comparison to conventional extraction method?

g) there is no discussion related to figure 1. 

h) conclusion and abstract should contain information what was the best extraction method, not only extraction condition.

Comments on the Quality of English Language

Extensive english editing required.

Author Response

The manuscript describes the influence of different extraction processes on composition and antioxidant activity of watercress ethanolic extract. The manuscript is not well organized and needs significant improvement in discussion and scientific soundness. The major issues are:

We would like to thank the reviewer for his/her comments in order to improve our manuscript.

1. a) english needs extensive revision

Our manuscript has been checked by a native English-speaking colleague.

1. b) introduction is too short and does not provide sufficient data regarding the background,aim and novelty. Include more data relating the different extraction processes, their benefits and disadvantages when they were used for other plant extracts.  What is conventional method for extraction of polyphenols, venefits and disadvantages,and what US and  PEF method offers better, why they are assumed as green merhod for extraction-clarify more

All suggested changes have been made to the introduction section.

1. c) line 59-60, the sentence is confusing. Does watercress have polyphenols or no? Why do authors perform extraction of polyphenols from watercress,if they say the absence of polyphenols...

As mentioned in lines 47 and 48, watercress contains a small amount of polyphenols. In order to be more precise, the sentence in line 80 has been changed.

1. d) materials and method section:

All used cgemicals need to be places in this section, not in supplementary material

All used chemicals have been placed in the Materials and Method section, as suggested.

Detailled extraction process needs to be written here, not in supplementary material

Detailed extraction methods have been written in the suggested section.

Detailled process of TPC and antioxidant activities need to be written in experimental part, it is not sufficient to just put a reference.

Detailed information about the process of TPC and antioxidant activities has been written in the experimental part.

1. e) table 1: include variables, i.e extractive parameters for every code sample to be able to follow results

The actual and coded levels of the independent variables are included in Table 1.

1. f) discussion related to the influence of different extractive merhods and extraction parameters on watercress extract quality needs to be improved. For example, add more data from literature related to plant extracts and optimal extractive conditions. How much US, ST and PEF single and in combination had efficiency in extraction of polyphenols from plants in literature? Is your proposed extractive merhod better, the same or worse when compare with the literature? How US and PEF are green extraction methods and why, in comparison to conventional extraction method?

More discussion has been done in the manuscript, as suggested.

1. g) there is no discussion related to figure 1. 

The discussion related to Figure 1 has been added, as suggested.

1. h) conclusion and abstract should contain information what was the best extraction method, not only extraction condition.

The best extraction method is referred to in line 19 in the abstract section and 412 in the conclusion section, as suggested.

Comments on the Quality of English Language

Extensive english editing required.

Our manuscript has been checked by a native English-speaking colleague.

Reviewer 4 Report

Comments and Suggestions for Authors

Using a main effect screening design (20 design points, 4 factors x 5 levels each) was used to optimize the process, the authors optimized a green extraction technique to maximize the recovery of antioxidant phenolics from watercress (Nasturtium officinale) leaves. A quite detailed and reproducible statistical analyses was applied. Point 13 exhibited the highest PC recovery while points 2 and 11 the maximum antioxidant capacity. The extraction technique seemed to play the most decisive role on PC recovery while concentration and temperature did on antioxidant capacity. Authors are advised to consider the following when preparing manuscript-v2 to improve its scientific soundness and uniqueness:

General. A) Please be consistent with all abbreviations throughout the manuscript, including their meanings the first time they are mentioned and, if possible, reduce their use. B) The comprehension of the manuscript could be improved if it is proofread by a native English-spoken colleague or if it is sent to a formal translation agency. C) Text plagiarism seems to be high (iThethicate report= 36%), please check an rephrase.

·       Title. OK.  

·       Abstract. This section should be succinct without sacrificing important experimental data (including p-values).

·       Introduction. A) It is suggested to construct paragraphs of 10-15 lines described in a more "effective" way (see: https://purdueglobalwriting.center/how-to-write-an-effective-paragraph/). B) Special emphasis should be placed on the uniqueness and scientific contribution of this new report compared to previous studies in the last paragraph.

·       Results/Discussion. A) Change the narrative of this section by eliminating unnecessary explanations and leaving only the description/induction of what was observed in graphs and tables. B) Both graphs and tables should comply with the minimum requirements of form and style of this journal. C) Figures should be improved (30o dpi or more). D) Since the surface graphs (Figure 1) support what is reported in Tables 1 and 2, it is advisable to send the graphs to the supplementary material. D) The discussion should be more inductive/comparative than descriptive, comparing results with previously reported on the same topic or near to it.

·       References. Double check for references not properly annotated.

 

Comments on the Quality of English Language

Moderate editing is needed

Author Response

Using a main effect screening design (20 design points, 4 factors x 5 levels each) was used to optimize the process, the authors optimized a green extraction technique to maximize the recovery of antioxidant phenolics from watercress (Nasturtium officinale) leaves. A quite detailed and reproducible statistical analyses was applied. Point 13 exhibited the highest PC recovery while points 2 and 11 the maximum antioxidant capacity. The extraction technique seemed to play the most decisive role on PC recovery while concentration and temperature did on antioxidant capacity. Authors are advised to consider the following when preparing manuscript-v2 to improve its scientific soundness and uniqueness:

We would like to thank the reviewer for his/her comments in order to improve our manuscript.

General. A) Please be consistent with all abbreviations throughout the manuscript, including their meanings the first time they are mentioned and, if possible, reduce their use. B) The comprehension of the manuscript could be improved if it is proofread by a native English-spoken colleague or if it is sent to a formal translation agency. C) Text plagiarism seems to be high (iThethicate report= 36%), please check an rephrase.

1. A) We have ensured that all abbreviations are consistent throughout the manuscript.
2. B) The manuscript has been revised following a proofread by a native English-speaking colleague to improve clarity.
3. C) The manuscript has been reviewed, and sections have been reworded as needed to guarantee originality and lower the similarity index.

• Title. OK.

Thank you.

• Abstract. This section should be succinct without sacrificing important experimental data (including p-values).

Done.

• Introduction. A) It is suggested to construct paragraphs of 10-15 lines described in a more "effective" way (see: https://purdueglobalwriting.center/how-to-write-an-effective-paragraph/). B) Special emphasis should be placed on the uniqueness and scientific contribution of this new report compared to previous studies in the last paragraph.

A great deal of effort has been made to improve the introduction and to emphasize the purpose and value of this experimental research, as proposed.

• Results/Discussion. A) Change the narrative of this section by eliminating unnecessary explanations and leaving only the description/induction of what was observed in graphs and tables. B) Both graphs and tables should comply with the minimum requirements of form and style of this journal. C) Figures should be improved (30o dpi or more). D) Since the surface graphs (Figure 1) support what is reported in Tables 1 and 2, it is advisable to send the graphs to the supplementary material. D) The discussion should be more inductive/comparative than descriptive, comparing results with previously reported on the same topic or near to it.

1. A) Done.
2. B) Compliance with journal requirements.
3. C) Figures are at 300 dpi resolution.
4. D) Moved Figure 1 to the supplementary material section.
5. E) Done.

• References. Double check for references not properly annotated.

Done.

Comments on the Quality of English Language

Moderate editing is needed

Our manuscript has been checked by a native English-speaking colleague.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have made the recommended changes. I recommend the article for publication.

Reviewer 3 Report

Comments and Suggestions for Authors

Authors sufficiently improved the manuscript,and I reccommend it for the publication.