Redox Potential and Its Control in Research and Commercial Wine Fermentations
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis review focuses on the redox potential and its function in fermentation. This is a good topic especially for a good control of fermentation.
This review is long but not well structured. As for me, it is a combination of pieces of information. It provided random clues but without clear organization and idea. A good review paper should not be mere a summary of published work, but should with a logic idea and presentation that is re-organized by the author using available information. A clear information and insight should be provided for readers.
I often got nowhere while reading. Some part is even redundant and irrelevant to the title, such as from part 19 to part 29.
The other problem I have been concerned is that many references are very old, even back to 1940s and even further. Some conclusion seems no longer valid for now. Please provide more modern cases.
Some part should be summarized more concisely, using some tables might be helpful for better gaining the main results from previous work, such as for Part 3 and 4.
Too much subtitles are listed, and many of them share the same topic and could be combined. Like some cases in Part 4 and 5 could be merged together.
I believe this review should be substantially revised especially in its organization to meet the standard of a review paper.
Author Response
Comment 1: This review is long but not well structured. As for me, it is a combination of pieces of information. It provided random clues but without clear organization and idea. A good review paper should not be mere a summary of published work, but should with a logic idea and presentation that is re-organized by the author using available information. A clear information and insight should be provided for readers. I often got nowhere while reading. Some part is even redundant and irrelevant to the title, such as from part 19 to part 29.
Response 1: We believe this to be an accurate and comprehensive review of the nature and control of this important, if forgotten environmental variable in wine (and other) fermentations. It contains, in addition to a summary and analysis of published work, clear research directions that might be taken, now that the control of the potential provides reproducible fermentation outcomes. As a comprehensive review, it is relatively long, however, we have included new tables (table abc and abc) to improve structure and readability. We have also significantly reorganized 19 sections into 8. We do not understand the reviewer’s comment on parts 19 to 29, as part 19 is the conclusion and final part.
Comment 2: The other problem I have been concerned is that many references are very old, even back to 1940s and even further. Some conclusion seems no longer valid for now. Please provide more modern cases.
Response 2: The importance of referring to early studies of the changes in potential during microbial activity, growth and to a lesser degree, fermentation is that the understanding that this is an environmental variable that influences microbial activity and fermentation outcomes is not new. Unfortunately, this seems to have been lost from recent wine research as simpler explanations have taken hold - such as dissolved oxygen and/or delivery of oxygen - rather than the actual response of the medium potential and its effects on microbial activity.
We reference few studies in the period 1980 to 2015, since there are few papers that reporting findings related to redox potential, to our knowledge. If the reviewer is aware of examples that we have missed we would appreciate learning of them.
Comment 3: Some part should be summarized more concisely, using some tables might be helpful for better gaining the main results from previous work, such as for Part 3 and 4.
Response 3: Thank you for your comment. We have added tables 1 and 2 to increase readability and conciseness.
Comment 4: Too much subtitles are listed, and many of them share the same topic and could be combined. Like some cases in Part 4 and 5 could be merged together.
Response 4: Thank you for your comment. We have significantly combined topic sections to improve readability and structure.
Reviewer 2 Report
Comments and Suggestions for AuthorsThe article presents the importance of redox potential in the wine fermentation process, emphasizing its role in the course of biochemical processes and its impact on wine quality. It also discusses the possibilities of controlling redox potential in order to optimize fermentation processes on a laboratory and industrial scale. The article contains theoretical considerations on redox potential based on the cited literature - 107 references. It is a good source of knowledge for both scientists and wine practitioners, presenting a new perspective on the management of fermentation processes by controlling redox potential.
Although the article is interesting, with an innovative perspective, in the opinion of the reviewer it requires some supplementation, especially in the case of the description of the effect of redox potential on the sensory profile of wine (chapter 8), where specific results of sensory studies conducted under controlled redox conditions are not presented.
Niestety, nie nie jest w tym miejscu możliwe jednoznaczne stwierdzenie wpływu potencjału na jakość wina. W opinii recenzenta fermentacja jabłkowo-mlekowa (MLF) również nie została w pełni omówiona – brakuje szczegółowych danych na temat Wpływ potencjału redoks na szybkość i wyniki tej fermentacji. W Dodatkowo na pierwszej stronie brakuje afiliacji autorów. Literatura powinna być również oceniane pod kątem wymagań czasopisma, ponieważ istnieją drobne braki w cytowaniu źródła, np.: 3,4,6, 7,8,11 itd. Kilka źródeł pochodzą z lat 30., 50. i 70. W ocenie recenzenta powinno to być rozważono, czy można znaleźć cytaty z ostatnich 20 lat.
Author Response
Comment 1: Although the article is interesting, with an innovative perspective, in the opinion of the reviewer it requires some supplementation, especially in the case of the description of the effect of redox potential on the sensory profile of wine (chapter 8), where specific results of sensory studies conducted under controlled redox conditions are not presented. Unfortunately, it is not possible at this point to clearly state the influence of potential on the quality of wine.
Response 1: Thank you for your comment. This review does not attempt, or claim to, assess the wine quality implications, since such reproducible experiments have yet to be done. The focus is on the nature and response of the redox potential during wine fermentation and the means by which it can be controlled. Such an understanding is missing from the wine literature, and it will enable others to conduct the experiments that the reviewer is anticipating.
Comment 2: In the reviewer's opinion, malolactic fermentation (MLF) was also not fully discussed - there is no detailed data on the influence of redox potential on the speed and results of this fermentation. In addition, the authors' affiliations are missing on the first page. The literature should also be assessed in terms of the journal's requirements, as there are minor gaps in the citation of the source, e.g.: 3,4,6, 7,8,11, etc. Several sources come from the 1930s, 1950s and 1970s. In the reviewer's opinion this should be considered if you can find quotes from the last 20 years.
Response 2: The importance of referring to early studies of the changes in potential during microbial activity, growth and to a lesser degree, fermentation is that the understanding that this is an environmental variable that influences microbial activity and fermentation outcomes is not new. Unfortunately, this seems to have been lost from recent wine research as simpler explanations have taken hold – such as dissolved oxygen and/or delivery of oxygen - rather than the actual response of the medium potential and its effects on microbial activity.
We reference few studies in the period 1980 to 2015, since there are few papers that reporting findings related to redox potential, to our knowledge. If the reviewer is aware of examples that we have missed we would appreciate learning of them.
The mention of the redox potential in regard to the malolactic fermentation is to bring older significant results into the modern literature, where is typically cannot be found. It is also to encourage a renewed understanding of the role of the potential versus the older aerobic/anaerobic descriptions that show no clear influence on either the rate of growth and malic conversion, or in the product formation. Again, the means of controlling the redox potential is an essential step in performing more significant research outcomes in this area.
Reviewer 3 Report
Comments and Suggestions for AuthorsThe manuscript, "Redox Potential and its Control in Research and Commercial Wine Fermentations," offers a comprehensive and insightful examination of the role of redox potential in wine fermentation processes. It addresses a wide range of topics, including the chemical foundations of redox potential, its impact on microbial activity and fermentation results, and its relevance to both research and industry practices. This subject is particularly pertinent and timely, given the importance of redox control in improving the quality and consistency of wine production.
While the manuscript references many complex processes and experimental results, visual aids are limited. Adding diagrams, flowcharts, or summary tables to illustrate key concepts and processes (e.g., redox potential dynamics during fermentation) would significantly improve comprehension.
I recommend the article for publication following minor revisions.
Author Response
Comment 1: While the manuscript references many complex processes and experimental results, visual aids are limited. Adding diagrams, flowcharts, or summary tables to illustrate key concepts and processes (e.g., redox potential dynamics during fermentation) would significantly improve comprehension.
Response 1: Thank you for your comment. We have added two new tables (table 1 and 2) to significantly improve comprehension.
Reviewer 4 Report
Comments and Suggestions for AuthorsThe review is well written and I recommend for publication after minor revisions. Some specific issues were not possible to address corrections because the there is not line numbers to refer. Please check for example:
Parenthesis inside parenthesis: “(according to Hewitt (1950) [15]),”
„Streptococci and Corynebacterium diphtheria“: Streptococci is in italic. Is Streptococci diphtheria a specie name?
Throughout the manuscript for citations the year of publication is provided: like “Shibai et al. (1974) [21]“ please check the journal guidelines fort hat.
Please check subscript numbers like “ H2S emission”
Please check the quality of all figures. Also texts embedded. They need to be clear and in better quality.
Please review the references. For example:
Marín Galvín, R.; Rodríguez Mellado, J.M.; Ruiz Montoya, M.; Jiménez Gamero, C. OXIDATION-REDUCTION POTENTIAL (ORP) IN PREPARED AND INDUSTRIALLY TREATED WATERS. Bol. Soc. Chil. Quím. 2001, 46, doi:10.4067/S0366- 16442001000400002.
25. Gillespie, L.J. REDUCTION POTENTIALS OF BACTERIAL CULTURE AND OF WATER-LOGGED SOILS: Soil Sci. 1920, 9, 199–216, doi:10.1097/00010694-192004000-00001.
Author Response
Comments 1: Parenthesis inside parenthesis: “(according to Hewitt (1950) [15]),”
Response 1: Thank you for your comment. This has been corrected.
Comments 2: Streptococci and Corynebacterium diphtheria“: Streptococci is in italic. Is Streptococci diphtheria a specie name?
Response 2: Thank you for your comment. Yes, Streptococci diphtheria is a species name and is therefore italicized.
Comments 3: Throughout the manuscript for citations the year of publication is provided: like “Shibai et al. (1974) [21]“ please check the journal guidelines fort hat.
Response 3: Thank you for your comment. Our intention is to include the date when it is important to relate when different understanding of redox in microbial systems was published. This is helpful as we describe a century of work in this area. We have verified with the journal guidelines.
Comments 4: Please check subscript numbers like “ H2S emission”
Response 4: This has been corrected to H2S emission
Comments 5: Please check the quality of all figures. Also texts embedded. They need to be clear and in better quality.
Response 5: The quality of the figures has been check and corrected if necessary.
Comments 6: Please review the references. For example:
Marín Galvín, R.; Rodríguez Mellado, J.M.; Ruiz Montoya, M.; Jiménez Gamero, C. OXIDATION-REDUCTION POTENTIAL (ORP) IN PREPARED AND INDUSTRIALLY TREATED WATERS. Bol. Soc. Chil. Quím. 2001, 46, doi:10.4067/S0366- 16442001000400002.
- Gillespie, L.J. REDUCTION POTENTIALS OF BACTERIAL CULTURE AND OF WATER-LOGGED SOILS: Soil Sci. 1920, 9, 199–216, doi:10.1097/00010694-192004000-00001.
Response 6: Thank you for your comment. The references have been reviewed and corrected.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe author did make some changes and it is reable for me. I accept the current form as it dose provide useful information. Still I insist that a good review paper should be more concise and summative, and the author should be aware of that in a future writing.
