The Phytochemical Profile and Antioxidant Activity of Thermally Processed Colorful Sweet Potatoes

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Manuscript title: Phytochemical profile and antioxidant activity of thermally 2 processed colorful sweet potatoes

Manuscript IS: horticulturae-2749049

The qualitative determination of various bioactive compounds due different types of coking is not a new concept as the literature already contains many similar studies. The interesting part of this particular manuscript however was the attempt done to correlate the different factors with the respective bioactive compounds, yet the authors failed to do so.

I suggest reconsidering this paper only looking at the amount work done and considering how good the information it could provide to the literature. Though, the authors need to revise the data presentation to a very clear, concise manner and present it in a standard scientific format.

 

See some of my feedback

Line 56-57: Studies showing the content of phenolic compounds after cooking foods are common, including sweet potatoes. It is not clear what the authors meant to say.

The fundamental issue regarding to data presentation as follows

Figures 2, and  figure 3, even though it is acceptable to  present results in one figure as plot primary and secondary axis, the authors attempted to present  five parameters in one figure for the six sample conditions per sample. For the starter, these six parameters include phenolic compounds, flavonoids, anthocyanins and antioxidant activity (TBARS and DPPH) have different units and different

 

 however, the axis’s represented only two parameters, mg 100 mg^-1 (anthocyanins) as y-axis and nmol TBARS g ^-1 in y-axis.

Same as above figure 6 and 7, is it scientifically acceptable to plot two different variables with different measurement criteria in one axis (phenolic compounds (mg GEA 100 mg^-1), and flavonoids (mg RE 100 mg^-1)

There is similar problem on figure 10, figure 11

Figure 8, figure 9, figure 12 only presented the correlation between PC1 & PC2, yet line 340, 358, 489the data variance presented including PC3. Ideally there was no comparison of any of the first and second components with the third component. Such presentation needs to be corrected.

 

If the authors managed to get these issues right, I believe it will be a good input for the industry or consumers who are actually aware of their nutrition and effect of processing.

Comments on the Quality of English Language

The English language is generally acceptable but it needs through reading.

Author Response

Dear Sir,

We would like to thank you for the review. Certainly, it was very important to improve the quality of our article.

We respond to the reviewer' remarks and we described the changes which have been made in the manuscript in the point-by-point reply. In the manuscript, changes are highlighted by red color.

 

Replies to referee’s comments

Reviewer #1: The qualitative determination of various bioactive compounds due different types of coking is not a new concept as the literature already contains many similar studies. The interesting part of this particular manuscript however was the attempt done to correlate the different factors with the respective bioactive compounds, yet the authors failed to do so.

I suggest reconsidering this paper only looking at the amount work done and considering how good the information it could provide to the literature. Though, the authors need to revise the data presentation to a very clear, concise manner and present it in a standard scientific format.

R: We appreciate the comments made by the reviewer for the improvement of the manuscript. The article has been adjusted in its entirety, where the graphs have been removed and replaced with tables, following the comments provided below. Furthermore, we have reviewed the written part, aiming to make the article clearer and more concise.

 

Reviewer #1: Line 56-57: Studies showing the content of phenolic compounds after cooking foods are common, including sweet potatoes. It is not clear what the authors meant to say.

R: The mentioned description has been removed from the manuscript as it was confusing.

 

Reviewer #1: The fundamental issue regarding to data presentation as follows.

Figures 2, and figure 3, even though it is acceptable to present results in one figure as plot primary and secondary axis, the authors attempted to present five parameters in one figure for the six sample conditions per sample. For the starter, these six parameters include phenolic compounds, flavonoids, anthocyanins and antioxidant activity (TBARS and DPPH) have different units and different. However, the axis’s represented only two parameters, mg 100 mg_-1 (anthocyanins) as y-axis and nmol TBARS g^-1 in y-axis.

R: All figures have been removed from the manuscript and replaced with tables that were previously in the supplementary material. We had included figures due to the large amount of data present in them. However, the figures indeed became confusing and did not represent the data in the best way.

 

Reviewer #1: Same as above figure 6 and 7, is it scientifically acceptable to plot two different variables with different measurement criteria in one axis (phenolic compounds (mg GEA 100 mg-1), and flavonoids (mg RE 100 mg-1).

R: As mentioned above, the figures have been removed from the manuscript and replaced by tables.

 

Reviewer #1: There is similar problem on figure 10, figure 11.

R: As mentioned above, the figures have been removed from the manuscript and replaced by tables.

 

Reviewer #1: Figure 8, figure 9, figure 12 only presented the correlation between PC1 & PC2, yet line 340, 358, 489the data variance presented including PC3. Ideally there was no comparison of any of the first and second components with the third component. Such presentation needs to be corrected. If the authors managed to get these issues right, I believe it will be a good input for the industry or consumers who are actually aware of their nutrition and effect of processing.

R: As mentioned above, the figures have been removed from the manuscript and replaced by tables.

 

 

Reviewer #1: The English language is generally acceptable but it needs through reading.

R: The text has been thoroughly reviewed.

 

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript refers to the study of bioactive compounds content and antioxidant capacity of different colorful sweet potatoes. Besides changes ocurred during different cooking methods were also asseed. The aim of the study is interesting and methods used are appropiate. However, manuscript must be modified before publishing.

Abstract is difficult to read, maybe because authors started writing all different compunds measured without other explanation or mentioning samples.

Keywords are not representative. Please choose other keywords to improve article difussion.

Introduction is too short and has not the sufficient information to understand the importance of the study. There is no need to make really long introductions but at least this must justify the study.

Section 2.1 has a wrong tittle

Line 89: Steaming is identified with letter "V", but in the results this is identified with "S"

Section 2.4: Which detector was used during HPLC? How did the authors identified the different compunds? Did they used standard or mass spectometry?

Section 2.6: I strongly believe that n=2 is not sufficient

The amount of results is so large that it makes it difficult to present them in a simple way. Although I understand that figures summarize the information of tables in the supplementary, some important information such as the stadard deviation or significant differences are omitted. Besides, colors used in figures are not different enough for different parameters.

Figure 5: Not all samples of 5623 are grouped in PC1+, nor Beauregard in PC1+ and PC2-.

 

Conclusion are not supported by the study. From line 539 to 542, authors stated that consumption of sweet potatoes studied is beneficial to human health, but the only performed quantification of bioactive compounds and in vitro techniques.

 

 

Comments on the Quality of English Language

English should be revised by someone who is native or has a real high level of knowledge of the lenguage

Author Response

Dear Sir,

We would like to thank you for the review. Certainly, it was very important to improve the quality of our article.

We respond to the reviewer' remarks and we described the changes which have been made in the manuscript in the point-by-point reply. In the manuscript, changes are highlighted by red color.

 

Replies to referee’s comments

 

 

Reviewer #2: The manuscript refers to the study of bioactive compounds content and antioxidant capacity of different colorful sweet potatoes. Besides changes ocurred during different cooking methods were also asseed. The aim of the study is interesting and methods used are appropiate. However, manuscript must be modified before publishing.

R: We appreciate the reviewer's comments, and the suggestions made below were essential for improving the manuscript.

 

Reviewer #2: Abstract is difficult to read, maybe because authors started writing all different compunds measured without other explanation or mentioning samples.

R: The abstract has been modified as suggested.

 

Reviewer #2: Keywords are not representative. Please choose other keywords to improve article difussion.

R: The keywords have been adjusted as suggested. Keywords: Ipomoea batatas; biogenic amines; polyphenolic compound; natural pigments.

 

Reviewer #2: Introduction is too short and has not the sufficient information to understand the importance of the study. There is no need to make really long introductions but at least this must justify the study.

R: The introduction has been completely revised to clarify the objective and justification.

 

Reviewer #2: Section 2.1 has a wrong tittle

R: We modified the section 2.1.

 

Reviewer #2: Line 89: Steaming is identified with letter "V", but in the results this is identified with "S"

R: We changed the letter.

 

Reviewer #2: Section 2.4: Which detector was used during HPLC? How did the authors identified the different compunds? Did they used standard or mass spectometry?

R: The information was added in Section 2.4. Lines 147-152: For that, the samples were extracted in mobile phase (50% solvent A: acidified water:  trifluoroacetic acid (99.9:  0.1, v/v) and 50% solvent B (100% acetonitrile) and centrifuged (5 min, 5000 × g). The supernatant was recovered, and an aliquot (20 µL) was injected into the HPLC system (Ultimate 3000, Thermo Scientific, Bremen, Germany) coupled to a DAD and C18 column (150 × 4.6 mm, Kinetex® 2.6 µm F5 100 Å; Phenomenex, USA). Linhas 158-160: Calibration curves were built using known amounts of analytical standards (99.98% pu-rity; Sigma–Aldrich Co., St. Louis, MO, USA).

 

Reviewer #2: Section 2.6: I strongly believe that n = 2 is not sufficient

R: Indeed, we had made a mistake in the wording, so the sentence has been revised. Lines 179-181: The HPLC analysis of the ten samples (5 purple-fleshed sweet potatoes and 5 or-ange-fleshed ones) was performed in duplicate for each of the three replications (n = 6).

 

Reviewer #2: The amount of results is so large that it makes it difficult to present them in a simple way. Although I understand that figures summarize the information of tables in the supplementary, some important information such as the stadard deviation or significant differences are omitted. Besides, colors used in figures are not different enough for different parameters.

R: In order to improve the presentation of the data, as also suggested by reviewer #1, we chose to keep the tables throughout the manuscript, as they indeed better represent the data than the previously presented figures.

 

Reviewer #2: Figure 5: Not all samples of 5623 are grouped in PC1+, nor Beauregard in PC1+ and PC2-.

R: The textual adjustment was made as suggested.

 

Reviewer #2: Conclusion are not supported by the study. From line 539 to 542, authors stated that consumption of sweet potatoes studied is beneficial to human health, but the only performed quantification of bioactive compounds and in vitro techniques.

R: We agree with the point raised by the reviewer, and we have adjusted the text by removing the information that was previously under discussion.

 

Reviewer #2: English should be revised by someone who is native or has a real high level of knowledge of the language.

R: The text has been reviewed in its entirety.

 

 

Reviewer 3 Report

Comments and Suggestions for Authors

First of all, I would say thanks to the editor for allowing me to review this research.

The work done by Basilio and the group has been very interesting and I can say that out of a box approach.     The whole MS is well-written and well-supported statistically.   There is only a minor concern about the latest references, in the whole MS no reference to the year 2023, and only 1 reference to the year 2022. So I must say authors try to add the latest references.   

Author Response

Dear Sir,

 

We would like to thank you for the review. Certainly, it was very important to improve the quality of our article.

 

Reviewer #3: First of all, I would say thanks to the editor for allowing me to review this research. The work done by Basilio and the group has been very interesting and I can say that out of a box approach. The whole MS is well-written and well-supported statistically. There is only a minor concern about the latest references, in the whole MS no reference to the year 2023, and only 1 reference to the year 2022. So I must say authors try to add the latest references.

R: Thank you for the reviewer's comment. The references have been reviewed and updated as suggested. References from 2022 and 2023 were added throughout the manuscript.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Authors have modified all the comments made in the first review and improved the manuscript.