Bioactivity of Grape Skin from Small-Berry Muscat and Augustiatis of Samos: A Circular Economy Perspective for Sustainability

Round 1

Reviewer 1 Report

1. The manuscript lacks novelty, the authors should point out and focus on the novelty side of the work, The work is simple and is not so much original. Authors should check the spelling. Several phrases and words throughout the test need editing

2. Abstract lacks data values based on the study's findings relating to different parameters.

3. The content of this paper is not technically accurate and sound.

4. The method should be summarized and made it more clear.

5. Lack of clear message in the sentences. Some sentences were poorly constructed. I am suggesting author to use short sentences to make his message clear.

6. Author should stick to one point per paragraph. There is a mix-up of points in one paragraph.

7. Results of the study have not been compared with the findings of earlier scientists.

8. The quality of the figures must be improved

9. Some paragraphs need to be broken for easy understanding.

10. Avoid redundant text.

11. Why is GC-MS not used for all analyses?

12. The "Conclusion" section should be enlarged by including specific results and conclusions drawn from them, not only the general conclusion of the manuscript.

Author Response

Response to Reviewer 1 Comments

Point 1: The manuscript lacks novelty, the authors should point out and focus on the novelty side of the work, The work is simple and is not so much original. Authors should check the spelling. Several phrases and words throughout the test need editing

Response 1: We thank the reviewer for pointing this out that helps make clear the concept of this work. Appropriate changes were made according to the reviewer’s comment and since small-berry Muscat and Augustiatis are two Greek unexplored grape varieties we highlight this as the novelty of the work in the rephrased last paragraph of the introduction “The aim of this study was to highlight bioactivities of grape skins from two unexplored winemaking grape varieties that are cultivated in the Greek Island of Samos in Northern Aegean from the perspective of the nutraceutical value related to antiatherogenic activities such as free radical scavenging, and inhibition of plasma oxidation and PAF-induced platelet aggregation. Total phenolics content (TPC), radical scavenging, inhibition of platelet aggregation, and of plasma oxidation were evaluated in grape skin methanolic extracts.” (lines 94-100 in the revised manuscript).

A new paragraph was also inserted that highlights the significance of the assays used for the evaluation of the grape skin bioactivities in terms of in vitro antiatherogenic activities (lines 84-93 in the revised manuscript).

spelling and editing throughout the text were also performed according to the reviewer’s advice.

 

Point 2: Abstract lacks data values based on the study's findings relating to different parameters.

Response 2: We agree with the reviewer’s notification. Data values of HPLC analysis were inserted in the abstract according to the reviewer's request.

 

Point 3: The content of this paper is not technically accurate and sound.

Response 3: By improving the text and by highlighting the innovation concerning unexplored local varieties and the use of assays aimed at investigating anti-oxidation and anti-thrombotic actions that are two key mechanisms of atherogenesis, underlying the development of cardiovascular diseases, we believe that the content of the paper is now technically accurate and sound.

Point 4: The method should be summarized and made it more clear.

Response 4: The methodology was revised according to the reviewer advice, and where possible, changes were made to make it clearer.

 

Point 5: Lack of clear message in the sentences. Some sentences were poorly constructed. I am suggesting author to use short sentences to make his message clear.

Response 5: We agree with the reviewer on this point. All paragraphs were checked, and shorter sentences were used to make the content clear.

 

Point 6: Author should stick to one point per paragraph. There is a mix-up of points in one paragraph.

Response 6: We agree with the reviewer’s comment. Paragraphs throughout the text, were separated to present one point per paragraph.

 

Point 7: Results of the study have not been compared with the findings of earlier scientists.

Response 7: We agree with the reviewer’s comment. Results have now been discussed and compared with findings of earlier studies in the expanded discussion section (lines 327-331; 335-341; 349-354; 356-360 in the revised manuscript) and the relative works were inserted in the references section.

 

Point 8: The quality of the figures must be improved

Response 8: We thank the reviewer for pointing this out and the Figures were replaced.

 

Point 9: Some paragraphs need to be broken for easy understanding.

Response 9: We understand the reviewer’s point and the paragraphs were broken in order to be easier understandable.

 

Point 10: Avoid redundant text.

Response 10: We thank the reviewer for this point. The text was revised and redundant text was omitted, taking care not to affect the meaning.

Changes led to the omission of the following references: Li et al., 2022;  Manjón et al., 2022; You et al., 2022; Constantin et al., 2021, de Alencar et al., 2022; Pavić et al., 2019; and Baron et al., 2021.

 

Point 11:  Why is GC-MS not used for all analyses?

Response 11: We used HPLC-DAD analysis as an appropriate technique for phenolic analysis. GC-MS is more suitable for fatty acids or volatile compounds.

 

Point 12: The "Conclusion" section should be enlarged by including specific results and conclusions drawn from them, not only the general conclusion of the manuscript.

Response 12: We agree with this point. The "Conclusion" section was enlarged by including the main results and conclusions drawn from them.

Reviewer 2 Report

The aim of the study was “to highlight the bioactivities of the grape skins from a white and a red winemaking grape variety that are cultivated in the Greek islands” “from the perspective of both the nutraceutical value and circular economy”. This aim is formulated too broadly since the study is limited to evaluation of radical scavenging, inhibition of platelet aggregation and of plasma oxidation were evaluated in grape skin methanolic extracts.

The study is not innovative; these problems have been studied previously by many authors. This knowledge concerning the antioxidant and anti-platelet activities of grapeskin extracts should be briefly mentioned under Introduction or in the Discussion and on this background, the novel aspects of the present study should be highlighted.

Suggestions concerning possibilities of applications of the grapeskins/grapeskin extracts resulting from the study would be valuable.

Line 72: “dehydrate”, dihydrate?

Lines 90, 91 and next: “oC”, please use “°C”

Lines 99: “equal to 100”, was it v/w ratio?

Line 148 and next: Please use µL instead of uL

Table 2. The title should be modified: “determination” is a procedure, the table presents results of this procedure

Author Response

Response to Reviewer 2 Comments

Point 1: The aim of the study was “to highlight the bioactivities of the grape skins from a white and a red winemaking grape variety that are cultivated in the Greek islands” “from the perspective of both the nutraceutical value and circular economy”. This aim is formulated too broadly since the study is limited to evaluation of radical scavenging, inhibition of platelet aggregation and of plasma oxidation were evaluated in grape skin methanolic extracts.

Response 1: We understand the reviewer’s comment and the aim of the study was rephrased as “The aim of this study was to highlight bioactivities of grape skins from two unexplored winemaking grape varieties that are cultivated in the Greek Island of Samos in Northern Aegean from the perspective of the nutraceutical value related to antiatherogenic activities such as free radical scavenging, and inhibition of plasma oxidation and PAF-induced platelet aggregation. Total phenolics content (TPC), radical scavenging, inhibition of platelet aggregation and of plasma oxidation were evaluated in grape skin methanolic extracts.” (lines 94-100 in the revised manuscript).

 

Point 2: The study is not innovative; these problems have been studied previously by many authors. This knowledge concerning the antioxidant and anti-platelet activities of grape skin extracts should be briefly mentioned in Introduction or in the Discussion and on this background, the novel aspects of the present study should be highlighted.

Response 2: We appreciate the reviewer bringing this to our attention since it clarifies the meaning of this work. Appropriate changes were made according to the reviewer’s comment and since small-berry Muscat and Augustiatis are two Greek unexplored grape varieties we highlight this as the novelty of the work in the rephrased last paragraph of the introduction “The aim of this study was to highlight bioactivities of grape skins from two unexplored winemaking grape varieties that are cultivated in the Greek Island of Samos in Northern Aegean from the perspective of the nutraceutical value related to antiatherogenic activities such as free radical scavenging and inhibition of plasma oxidation and PAF-induced platelet aggregation. Total phenolics content (TPC), radical scavenging, inhibition of platelet aggregation, and of plasma oxidation were evaluated in grape skin methanolic extracts.” (lines 94-100 in the revised manuscript).

Information on the bioactivities of grape skin extracts was added in the Introduction (lines 75-93) and innovative characteristics of the current investigation is emphasized by highlighting the significance of the assays used for the evaluation of the grape skin bioactivities in terms of in vitro antiatherogenic activities (lines 75-93 in the revised manuscript): “Grape skin has been recognized for its large quantities of bioactive compounds (de Andrade et al., 2021; Serea et al., 2021), that adds value to these byproducts owing to the possibility for various applications in the food and pharmaceutical sectors (Felice et al., 2012; Soares De Moura et al., 2012; Constantin et al., 2021). Previous studies have referred to antioxidant, antibacterial, anti-inflammatory, anti-obesity, and anticancer properties of the biomolecules that are obtained from grape skin(Morré and Morré, 2006; Oueslati et al., 2016; Bomfim et al., 2019; Pavić et al., 2019; Sochorova et al., 2020; De Costa et al., 2020; Baron et al., 2021; de Alencar et al., 2022; Fernández-Fernández et al., 2022; Gorrasi et al., 2022; Mokrani et al., 2022).

Other studies have shown that oxidation of plasma lipoproteins has been demonstrated to initiate atherosclerosis at the molecular level. This oxidation procedure results in the production of thrombotic and inflammatory lipid mediators such as plate-let-activating factor (PAF) and PAF-like oxidized phospholipids, which mediate the early stages of inflammation on the aortic endothelium as well as thrombosis and free radical production(Demopoulos, Karantonis and Antonopoulou, 2003; Pégorier et al., 2006; Boffa and Koschinsky, 2019). In addition, minor bioactive substances in plant-origin foods that exhibit antioxidant and/or PAF inhibitory effects have been shown in studies to be important in the prevention of cardiovascular disease (Demopoulos, Karantonis and Antonopoulou, 2003; Nomikos, Fragopoulou, and Antonopoulou, 2007).

 

Point 3: Suggestions concerning the possibilities of applications of the grapeskins/grapeskin extracts resulting from the study would be valuable.

Response 3: We thank the reviewer for this advice. In the conclusion section, the following text was introduced: “The results indicate that grape skins of small berry muscat and Augustiatis could be the subject of a mixture design for the formulation of new enriched healthy animal or plant food products such as meat products, dairy products, bakery snacks, traditional pasta, spread products, beverages or even wine with increased antioxidant and antiplatelet activities.” (lines 405-409 in the revised manuscript).

 

Point 4: Line 72: “dehydrate”, dihydrate?

Response 4: We thank the reviewer for pointing this out. dehydrate was corrected to dihydrate

 

Point 5: Lines 90, 91, and next: “oC”, please use “°C”

Response 5: We appreciate the reviewer pointing this up. “oC” was corrected to “°C”

 

Point 6: Lines 99: “equal to 100”, was it v/w ratio?

Response 6: We understand the reviewer’s point. v/w was added in the text

 

Point 7: Line 148 and next: Please use µL instead of uL

Response 7: We agree with the reviewer on this point. uL was replace by μL throughout the text

 

Point 8: Table 2. The title should be modified: “determination” is a procedure, the table presents results of this procedure

Response 8: We recognize the reviewer's position. The title of table 2 was modified from “Total phenolic and radical scavenging activity determination.” to “Total phenolic content and radical scavenging activities.”

Round 2

Reviewer 1 Report

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Reviewer 2 Report

I am satisfied with the authors' reply and amendments