Innovation and Winemaking By-Product Valorization: An Ohmic Heating Approach

Round 1

Reviewer 1 Report

It is undeniable that the authors did some meaningful and practical work to evaluate the possibility of the OH approach as an alternative method to reuse the by-products of winemaking. However, I have to say the text and details, especially the tables and figures, need a major revision. Specifically as follows:

1. The citation format of references in this manuscript is not uniform, such as line 58 and line 75. And this error runs throughout the manuscript.

2. The introduction should focus on the application and potential of the Ohmic heating approach in the field of the food industry or other fields, rather than the background and reuse of grape and wine by-products.

3. The title of Table 1 seems to be wrong.

4. The footnote in Table 1 does not indicate the level of significant difference between the superscript "*" and "**”.

5. There are two confusing names and their abbreviations for fruit dregs, including bagasse and pomace, see line 158, line 350, and Table 1. And this error runs throughout the manuscript.

6. The three tables have three formats. And there are unaligned data forms in Table 1. Table 2 has a background color, and the fonts in Table 3 are not consistent with the other two tables.

7. There are no significant difference markers corresponding to footnotes in Table 2.

8. It would be better if the results in 3.4.1 and 3.4.2 could also be presented in a table.

9. The border color in Figure 1 and Figure 2 is not consistent, and the font in the figure is not uniform.

10. Figure 1 in line 494 should be Table 2.

11. The vertical titles in Figures 1 and 2 do not match the figures' captions.

12. Regarding line 555, Figures 1 and 2 do not give information about SF.

13. The analysis and discussion of the results in 3.5.2 should be more adequate and logical.

Author Response

Dear Reviewer,

First, the authors sincerely acknowledge the interest demonstrated in our work and the availability to reconsider a revised version of this manuscript. 

We want to thank all the positive inputs and suggestions given by the reviewers, which will contribute to improving and enriching this manuscript.

The answers are given just after the transcription of reviewers’ comments, and new information added to the article is with track changes as requested in the revised version.

Reviwer 1

It is undeniable that the authors did some meaningful and practical work to evaluate the possibility of the OH approach as an alternative method to reuse the by-products of winemaking. However, I have to say the text and details, especially the tables and figures, need a major revision. Specifically as follows:

The citation format of references in this manuscript is not uniform, such as line 58 and line 75. And this error runs throughout the manuscript.

1. The references were made consistent.

2. The introduction should focus on the application and potential of the Ohmic heating approach in the field of the food industry or other fields, rather than the background and reuse of grape and wine by-products.
3. As we have already did a significant revision on OH in 101-125 application in particular in wine industry we considered that is enoughto frame the innovation of the study. We have maintained the initial context about the byproducts since it is one of the main topics is the valorization, and because reviewer 2 also asked to emphasize this topic.

3. The title of Table 1 seems to be wrong.
4. The title was changed accordingly.

4. The footnote in Table 1 does not indicate the level of significant difference between the superscript "*" and "**”.
5. The differences were indicated accordingly.

5. There are two confusing names and their abbreviations for fruit dregs, including bagasse and pomace, see line 158, line 350, and Table 1. And this error runs throughout the manuscript.
6. The substitution was performed.

6. The three tables have three formats. And there are unaligned data forms in Table 1. Table 2 has a background color, and the fonts in Table 3 are not consistent with the other two tables.
7. The tables were changes accordingly.

7. There are no significant difference markers corresponding to footnotes in Table 2.
8. The significant differences were indicated in table 2.

8. It would be better if the results in 3.4.1 and 3.4.2 could also be presented in a table.

The results are in table 1 and were indicated in each section.

9. The border color in Figure 1 and Figure 2 is not consistent, and the font in the figure is not uniform.
10. The borders were altered.

10. Figure 1 in line 494 should be Table 2.
11. The indication was changed accordingly.

11. The vertical titles in Figures 1 and 2 do not match the figures' captions.
12. The legends were modified accordingly.

12. Regarding line 555, Figures 1 and 2 do not give information about SF.
13. The information is given in table 2, and the alteration in the text was performed accordingly.

13. The analysis and discussion of the results in 3.5.2 should be more adequate and logical.
14. The results and discussion was improved accordingly.

Author Response File: Author Response.pdf

Reviewer 2 Report

This work presents interesting results of winemaking’s by-product valorization. The new approaches to revalorising the enological waste are in the new research tendencies. The research group used an extraction method that could improve the by-product extraction. However, the research paper should be improved.

Abstract

Line 33: cite correctly the anthocyanins…delphinidin-3-o-glucoside

Introduction

Lines 58, 62, 69: references in numbers

Lines 71-88: Research on bagasse and grape skin is quite abundant and it’s not reflected in the text. Please look closely at this part to improve it.

Materials and Methods

Line 161: please provide the maximum particle size of the stems.

Lines 166-173: I think it is not necessary to write this paragraph here.

Line 179: Instead of the oven method….very generic…please provide the number of the AOAC method.

Line 184: Please provide a method or have you measured that 3 hours were enough time to ignite?

Line 187: Why 6.25 kjeldahl factor? Why not different for bagasse than for stems?

Lines 187-193: Please provide the references of AOAC methods…and eliminate line 194 concerning AOAC.

Line 214: Please put HPLC after high-performance liquid chromatography

Line 261: space before Pereira

Line 270: “as mentioned before” not enough, could you give again the centrifugation conditions?

Line 294: “A mixture of the sample” of all?

Line 295: sodium carbonate 75 g/L??? it is not 7.5 g/L??

Line 313: HPLC-DAD

Line 318: Please provide the reference of the guard column

Lines 319-321: Pleas, TFA % must be included in the percentages of solvents.

Line 333: Please rewrite the sentence.

In Results and Discussion

References are shown with names and not with numbers as the guide of authors indicates.

Tables:

Table 1, the statistical analysis is correct? Some numbers have moved in the table (lignin content of WGS and RGS)

Table 2: I think it would be better one decimal in total antioxidant activity.

Table 3: Please correct the decimal adjust of ferulic acid, coumaric acid, caffeic acid and others.

Discussion:

Lines 364-373: Only one reference? There are so many references about ultrasounds to valorize grape pomace.

Line 394: Please provide any justification.

Lines 425-432: Is it similar to your results? The last sentence (429-432) could be sum up with other applications of dietary fibre that you cited before (lines 411-416).

Lines 441-442: This sentence again is repetitive.

Lines 525-526: like other technologies or not?... the OH temperature does not affect?

Conclusion:

I think that the conclusion must focus on the results of the paper (data) and at the end, give some perspectives.

Author Response

Dear Reviewer,

First, the authors sincerely acknowledge the interest demonstrated in our work and the availability to reconsider a revised version of this manuscript. 

We want to thank all the positive inputs and suggestions given by the reviewers, which will contribute to improving and enriching this manuscript.

The answers are given just after the transcription of reviewers’ comments, and new information added to the article is with track changes as requested in the revised version.

Reviewer 2

Abstract

Line 33: cite correctly the anthocyanins…delphinidin-3-o-glucoside

1. The names were improved accordingly in all paper.

Introduction

Lines 58, 62, 69: references in numbers

1. The references were improved accordingly.

Lines 71-88: Research on bagasse and grape skin is quite abundant and it’s not reflected in the text. Please look closely at this part to improve it.

1. The introduction was improved.

Materials and Methods

Line 161: please provide the maximum particle size of the stems.

1. The particle size of the stems was indicated in methods (<1.5 mm).

Lines 166-173: I think it is not necessary to write this paragraph here.

1. The authors wrote a paragraph to explain the need to characterize samples.

Line 179: Instead of the oven method….very generic…please provide the number of the AOAC method.

1. The information was improved.

Line 184: Please provide a method or have you measured that 3 hours were enough time to ignite?

1. Yes, the total time of methodology is more. Samples are overnighted in the oven but are 3 hours at 550 ºC.

Line 187: Why 6.25 kjeldahl factor? Why not different for bagasse than for stems?

6. the authors used the same, based on Kjeldahl method AOAC 2000 and other studies. A conversion factor of 6.25 (equivalent to 0.16 g nitrogen per gram of protein) was used to convert the measured nitrogen content to protein content.

Lines 187-193: Please provide the references of AOAC methods…and eliminate line 194 concerning AOAC.

1. The line was improved accordingly.

Line 214: Please put HPLC after high-performance liquid chromatography

1. The sentence was improved.

Line 261: space before Pereira
R. The space was eliminated.

Line 270: “as mentioned before” not enough, could you give again the centrifugation conditions?

1. The conditions was gived again.

Line 294: “A mixture of the sample” of all?

1. The english was improved, is not a a mixture of samples, but a reaction between sample and reagents.

Line 295: sodium carbonate 75 g/L??? it is not 7.5 g/L??

7. 7.5 g/L

Line 313: HPLC-DAD

1. It was uniform in all text.

Line 318: Please provide the reference of the guard column

1. The references were included.

Lines 319-321: Pleas, TFA % must be included in the percentages of solvents.

1. The percentage was included.

Line 333: Please rewrite the sentence.

The sentence was rewrited.

In Results and Discussion

References are shown with names and not with numbers as the guide of authors indicates.

1. the references were improved.

Tables:

Table 1, the statistical analysis is correct? Some numbers have moved in the table (lignin content of WGS and RGS)

1. yes, the table was improved.

Table 2: I think it would be better one decimal in total antioxidant activity.

1. the table was improved.

Table 3: Please correct the decimal adjust of ferulic acid, coumaric acid, caffeic acid and others.

1. The table was improved.

Discussion:

Lines 364-373: Only one reference? There are so many references about ultrasounds to valorize grape pomace.

1. The references were improved.

Line 394: Please provide any justification.

1. The justification was provided, the winemaking process of cultivars is different which influences the minerals content.

Lines 425-432: Is it similar to your results? The last sentence (429-432) could be sum up with other applications of dietary fibre that you cited before (lines 411-416).

1. Yes, the authors found that different cultivars present different fibre content ranging from 50% to 90%.

Lines 441-442: This sentence again is repetitive.

1. The sentence was eliminated.

Lines 525-526: like other technologies or not?... the OH temperature does not affect?

1. the sentence was improved. The OH temperature did not affect the protein in this case, because the temperature is not higher and the heating process is very fast, only causing electroporation cells.

Conclusion:

I think that the conclusion must focus on the results of the paper (data) and at the end, give some perspectives.

1. The conclusion was improved.

Round 2

Reviewer 1 Report

The issues mentioned in the previous comments have been revised. It is recommended to be accepted in its current form.

Author Response

Dear Reviewer,

First, the authors sincerely acknowledge the interest demonstrated in our work and the availability to reconsider a revised version of this manuscript. 

We want to thank all the positive inputs and suggestions given by the reviewers, which will contribute to improving and enriching this manuscript.

Kind regards,

Manuela Pintado