Browning Development and Antioxidant Compounds in White Wines after Selenium, Iron, and Peroxide Addition

Round 1

Reviewer 1 Report

This is a report about the effect of oxidants, such as Fe²⁺ and H₂O₂ and antioxidant (Se) on browning rate oxidation of white wines. Browning is related with polyphenol oxidation and leads to a decrease of organoleptic properties of white wines.

The introduction is comprehensive and well stated but some bibliographic references should be added to complete the state of art.

Is a simple experimental design, but adequate methodology allowing to obtain results according to the main objective of the study.

In general the authors tried to explain correctly the results, and compare it with other data available. However a paper about Greek wines should be used for results comparation. The conclusions are supported by the data obtained.

Author Response

RESPONSE TO REVIEWERS

 

On behalf of all the authors, we would like to thank the reviewers for improving our initially submitted manuscript.

Reviewer 1

This is a report about the effect of oxidants, such as Fe²⁺ and H₂O₂ and antioxidant (Se) on browning rate oxidation of white wines. Browning is related with polyphenol oxidation and leads to a decrease of organoleptic properties of white wines.

The introduction is comprehensive and well stated but some bibliographic references should be added to complete the state of art.

• More references were added (21,22,23,28,29)

Is a simple experimental design, but adequate methodology allowing to obtain results according to the main objective of the study.

In general the authors tried to explain correctly the results, and compare it with other data available. However a paper about Greek wines should be used for results comparation. The conclusions are supported by the data obtained.

• Papers about Greek wines are mentioned (14,26,27) and results are compared with previously obtained results concerning Greek wines (lines 192-193)

 

Reviewer 2 Report

The manuscript “Browing development and antioxidant compound in white wines after selenium, iron, and peroxide addition” explore the oxidability of wines exposed to high temperature mostly during storage and shipping.

The author said that they were the first exploring the effect of of selenium. However there are in literature some research about winemaking with selenium-enriched yeast that can be reported in the introduction section.

 

The paper is well structured, the chemical analysis supported all the aspect of wine detrimental. However I would have applied the DoE (Design of Experiment) to set the real experiments to carried on in the lab. The results would be more interesting and with the prediction of the data not tested. I would ask the authors if they have explored this possibility and why they didn’t use it.

 

The manuscript is suitable for publication in Applied Science but I would suggest a minor revision before the publication.

 

Here below some comments.

 

Please, correct as follow:

 

Line 12: please write “Selenium (Se)” because it is the first time that it is written along all the manuscript.

Line 12 and 15: SO2 please write correctly and check for it along all the manuscript

Line 13 and 16: H2O2 please write correctly and check for it along all the manuscript

Line 16: Fe2+ please write correctly and check for it along all the manuscript

Line 27: please change “promoted” with “promote”

Line 39: “bottled wines” instead of “bottle wines”

Line 42: I do not understand the meaning of “bottle bouquet”, please explain it

Line 78: please write “mole-1” correctly

Line 100: please add references for temperature. See for example:

 

Robinson AL, Mueller M, Heymann H, Ebeler SE, Boss PK, Solomon PS and Trengove RD. 2010. Effect of simulated shipping conditions on sensory attributes and volatile composition of commercial white and red wines. Am J Enol Vitic 61:337-347.

Walther AK, Durner D and Fischer U. 2018. Impact of temperature during bulk shipping on the chemical composition and sensory profile of a Chardonnay wine. Am J Enol Vitic 69:247-257.

 

Line 109: please write V.vinifera sp in italics

Table 1: I think that table 1 needs a revision. The sample “Control” in all the figures is named as “M”, so please, uniform that!  The concentration of Fe and H2O2 are not the same of the text at line 116-117. Please check that and uniform it with table 1.

 

Line 123: I would suggest to add a paragraph where report all the chemicals, reagents and instruments used for the analysis

Line 128: please add “12 days” somewhere in this part of the text explaining that the wines were kept for 12 days

Line 147: catechin is (+)-catechin? Please verify it

Line 153: The method for AR antioxidant activity is missing. Please verify it and add the method used

Line 166: please correct A420

Figure 1: correct SO2 and °C in the legend, it must be written correctly

Figure 3: in the first plot “a)” is missing, please add it; in plot c) and d) please change gallic acid with GAE like in the text of the manuscript and do the same in the figure legend

Figure 4: check if catechin is (+)-catechin and correct it in the figures and in the figure legend

Table 3 and 4: change “control” with “M”

 

 

 

Author Response

RESPONSE TO REVIEWERS

 

On behalf of all the authors, we would like to thank the reviewers for improving our initially submitted manuscript. All changes are marked with yellow for your convenience.

 

Reviewer 2

The manuscript “Browning development and antioxidant compound in white wines after selenium, iron, and peroxide addition” explore the oxidability of wines exposed to high temperature mostly during storage and shipping.

The author said that they were the first exploring the effect of selenium. However there are in literature some research about winemaking with selenium-enriched yeast that can be reported in the introduction section.

• A paragraph was added about selenium-enriched yeasts (lines 87-96)

The paper is well structured, the chemical analysis supported all the aspect of wine detrimental. However I would have applied the DoE (Design of Experiment) to set the real experiments to carried on in the lab. The results would be more interesting and with the prediction of the data not tested. I would ask the authors if they have explored this possibility and why they didn’t use it.

• We would like to thank the reviewer for this comment. Indeed, it would be the best option. However, we did not consider this at the beginning while setting up the experiment. Given the situation, we tried our best to interpret the results and to arrive to conclusions supported by our findings.

Line 12: please write “Selenium (Se)” because it is the first time that it is written along all the manuscript.

• Corrected

Line 12 and 15: SO2 please write correctly and check for it along all the manuscript

• Corrected

Line 13 and 16: H2O2 please write correctly and check for it along all the manuscript

• Corrected

Line 16: Fe2+ please write correctly and check for it along all the manuscript

• Corrected

Line 27: please change “promoted” with “promote”

• Corrected

Line 39: “bottled wines” instead of “bottle wines”

• Corrected

Line 42: I do not understand the meaning of “bottle bouquet”, please explain it

• Corrected

Line 78: please write “mole-1” correctly

• Corrected

Line 100: please add references for temperature. See for example:

Robinson AL, Mueller M, Heymann H, Ebeler SE, Boss PK, Solomon PS and Trengove RD. 2010. Effect of simulated shipping conditions on sensory attributes and volatile composition of commercial white and red wines. Am J Enol Vitic 61:337-347.

Walther AK, Durner D and Fischer U. 2018. Impact of temperature during bulk shipping on the chemical composition and sensory profile of a Chardonnay wine. Am J Enol Vitic 69:247-257.

• The two refs were included in the text (28,29)

Line 109: please write V.vinifera sp in italics

• Corrected

Table 1: I think that table 1 needs a revision. The sample “Control” in all the figures is named as “M”, so please, uniform that!  The concentration of Fe and H2O2 are not the same of the text at line 116-117. Please check that and uniform it with table 1.

• Corrected

Line 123: I would suggest to add a paragraph where report all the chemicals, reagents and instruments used fo SO₂ the analysis

• Lines 134-136 were added

Line 128: please add “12 days” somewhere in this part of the text explaining that the wines were kept for 12 days

• Added

Line 147: catechin is (+)-catechin? Please verify it

• Corrected

Line 153: The method for AR antioxidant activity is missing. Please verify it and add the method used

• Method description was added (lines 174-176)

Line 166: please correct A420

• Corrected

Figure 1: correct SO2 and °C in the legend, it must be written correctly

• Corrected

Figure 3: in the first plot “a)” is missing, please add it; in plot c) and d) please change gallic acid with GAE like in the text of the manuscript and do the same in the figure legend

• Corrected

Figure 4: check if catechin is (+)-catechin and correct it in the figures and in the figure legend

Table 3 and 4: change “control” with “M”

• Changed

 

Reviewer 3 Report

The manuscript entitled “Browning development and antioxidant compounds in white wines after selenium, iron, and peroxide addition” have described the browning capacity, phenolic composition, antioxidant activity and the SO₂ content of white wines with addition of Fe²⁺ and H₂O₂ and Se at two temperatures regimes. The subject of the manuscript is topical, but I recommend the publishing of the paper after the necessary corrections.

1. There are several typographical mistakes as well in whole manuscript. Therefore, the author’s thoroughly careful check the language and typo mistake to minimize the error.
2. Check and format the citations in the whole manuscript. Also, Appropriate references must be provided to explained the background, what is already done and why this study carried out. Hypothesis statement is missing in the introduction section.
3. The authors did not list the all used chemicals in the study. Where they were purchased? Producer?
4. General remark to the discussion - In my opinion, the discussion provided by authors is difficult to follow and verify due missing critical details in the methodology section. The analytical method used in determining antioxidant activity is missing.
5. Figure 3: “mM Trolox” and “Gallic acid mg/L”needs to be modified with “TE mg/L” and “GAE mg/L”.

Author Response

RESPONSE TO REVIEWERS

 

On behalf of all the authors, we would like to thank the reviewers for improving our initially submitted manuscript. All changes are marked with yellow for your convenience.

 Reviewer 3

The manuscript entitled “Browning development and antioxidant compounds in white wines after selenium, iron, and peroxide addition” have described the browning capacity, phenolic composition, antioxidant activity and the SO₂ content of white wines with addition of Fe²⁺ and H₂O₂ and Se at two temperatures regimes. The subject of the manuscript is topical, but I recommend the publishing of the paper after the necessary corrections.

1. There are several typographical mistakes as well in whole manuscript. Therefore, the author’s thoroughly careful check the language and typo mistake to minimize the error.

• We have corrected several mistakes throughout the manuscript.

 

2. Check and format the citations in the whole manuscript. Also, Appropriate references must be provided to explain the background, what is already done and why this study carried out. Hypothesis statement is missing in the introduction section.

• More references were added (21,22,23,28,29)

The research hypothesis is described clearly:

Since both the presence of metal ions (such as Fe²⁺) and H₂O₂ is known to increase browning rate, it was anticipated that their simultaneous addition in white wines would further reduce the time needed for the completion of the browning test. It was also of interest to monitor the polyphenolic composition, since these compounds are mostly implicated in the oxidation phenomena and to evaluate the effect of the addition of an antioxidant substance which could offer protection through various antioxidant mechanisms, such as Se.

 

3. The authors did not list the all used chemicals in the study. Where they were purchased? Producer?

• Added (lines 120-126)

 

4. General remark to the discussion - In my opinion, the discussion provided by authors is difficult to follow and verify due missing critical details in the methodology section. The analytical method used in determining antioxidant activity is missing.

• The method was added at the materials and methods section (lines 174-176)

 

5. Figure 3: “mM Trolox” and “Gallic acid mg/L”needs to be modified with “TE mg/L” and “GAE mg/L”.

• Corrected