Microbial Composition, Bioactive Compounds, Potential Benefits and Risks Associated with Kombucha: A Concise Review

Round 1

Reviewer 1 Report

Dear authors,

Please refer to the attached Word file with my comments. 

Comments for author File: Comments.pdf

Author Response

Reviewer 1

1. L2-3: Based on the layout of this review addressed above, I deem that the present title is narrower than its actual scientific content. Suggest revising the title to make it broader, at least including the kombucha bioactivity/health benefits.

We have changed the title (L2-L3). Thank you for your valuable suggestion.

2. L13-14 and throughout the manuscript: Why do the authors use bold-letter writing for the Komagataeibacter genus and species only? Please delete bold or otherwise explain this special writing choice.

The issue has been addressed in the abstract (L15-17) and throughout the affected sections, thank you.

3. L23: Please explain SCOBY in the abstract, which must be self-standing.

SCOBY has been included in the abstract (L12-13). Thank you for your suggestion.

4. L48-49: Here from citation 13 the text moves to citations 15 and 16; that means the article Reference 14, existing in the Ref list, has not been cited. Please correct.

All the in-text citations and the Reference section have been checked and corrected. Thank you.

5. L60-88 and Figure 2: Actually I cannot understand what is the validity of describing this WoS and Scopus search literature approaches? Particularly the first part (L60-76) could be deleted because does not offer anything to the scientific content and impact of this review.

Part of L60-L76 has been deleted. However, we left a starting sentence that links to the next sentence (L105-106).

6. L74-75: Delete the gap between the two parts of this sentence.

The gap has been deleted. Thank you.

7. L96: You mention citation [78] here, after the previous citation [23]. Obviously, need to correct the order of this reference.

The order of reference has been corrected (L186); thank you.

8. L142: Please cite and include in the References section the effective publication that reclassified the genus Acetobacter as Komagataeibacter.

Articles that reclassified Acetobacter xylinum as Gluconobacter xylinum and latter Komagataeibacter xylinum have been included (L206). Thank you.

9. L153-157: Please simplify and clarify the meaning of this long sentence by splitting it in two shorter sentences.

This issue has been addressed (L291-295). Thank you.

10. L202: please close the bracket ) before [6].

The bracket has been addressed (L407-L408). Thank you for your observation.

11. 
    L208: Delete ‘in kombucha’ after Glucuronic acid – not needed, viz. L209. L277: Delete this heading.

‘In kombucha (L418)’ and ‘of kombucha (L419)’ have been deleted, and L277 has also been deleted. Thank you.

12. L402-403: This reference 14 has not been cited – see L48-49 above.

Thank you for your comment. This has been rectified.

Reviewer 2 Report

Brief abstract 

In this work a general review of the characteristics and health properties of kombucha is made. It is quite an interesting idea, although the development of the work is not very innovative. After a thorough analysis of the article, some flaws are detected. The title does not accurately reflect the content of the article, which may mislead readers looking for specific information. In addition, the content is not well organized; there are different sections for the same content and, as a result, it fails to connect ideas and concepts effectively. In addition, the content of the article seems too basic, lacking a deeper analysis of the relevant issues and more critical thinking. A more coherent, informative and accurate representation of the content would be recommended. 

 

Particular comments to improve the article:  

• A general revision of the text is needed; the manuscript has some errors. In this regard, why do the authors use boldface in the genera of microorganisms?  

•  Lines 75-75: it is a meaningless sentence.  

•  Line 277: it is a meaningless sentence.  

•  Tables and figures. It is recommended that the author include tables to summarize the contents, providing readers with a clear and concise view of the topics covered. In addition, the figures presented in the article require careful review, as they contain errors that may affect the understanding of the data.  

•  Reorganize the same contents in related sections.  

•  Section 1.13. Please reconsider whether this section is necessary for the development of the article.  

•  Conclusions should be rewritten because they are not sufficiently supported by the content of the article, e.g., there is no information on the use of SCOBY in brewing and yet this is part of the conclusions.

Author Response

The title has been changed, thank you.

1. A general revision of the text is needed; the manuscript has some errors. In this regard, why do the authors use boldface in the genera of microorganisms?

It has been addressed, thank you.

2. Lines 75-75: it is a meaningless sentence.

This sentence has been deleted, thank you. 

3. Line 277: it is a meaningless sentence.

Line 277 has been deleted, thank you. 

4. Tables and figures. It is recommended that the author include tables to summarize the contents, providing readers with a clear and concise view of the topics covered. In addition, the figures presented in the article require careful review, as they contain errors that may affect the understanding of the data.  

 Reorganize the same contents in related sections.  

Summarizing contents in the Tables would be another option, but we selected Figures. Thank you for your suggestion.

5. Section 1.13. Please reconsider whether this section is necessary for the development of the article.

The section is necessary because there is still much research to be done using rooibos as a tea base for kombucha production. Thank you.

6. Conclusions should be rewritten because they are not sufficiently supported by the content of the article, e.g., there is no information on the use of SCOBY in brewing and yet this is part of the conclusions.

‘The use of SCOBY in brewing’ mentioned in the Conclusions has been deleted though we thought mentioning the use of SCOBY in the conclusions would be part of recommended future research. Thank you.

 

Reviewer 3 Report

Kombucha is a fermented tea beverage containing bioactive compounds from tea and vital  compounds like acetic acid, glucuronic and gluconic acids produced from the metabolic activities

of bacteria and yeasts, which benefit human health.

I think  Kombucha  was discussed  Comprehensively  in this  review, it can be published after the authors make some revise. My revision opinions are as follows:

1、D-Glucaric acid,1,4-lactone is one of  most important bioactive compounds in Kombucha，  It has increasing the immune function and reducing the risks of cancers, author should supplement some  information  about this issue.

 2、All of the  Acetobacter,   Komagataeibacter was used as  the prefix name,   please check the most popular name, which  were used in literature.

3、 Rooibos was used as tea base for Kombucha , it is a good idea , can author supplement some  information about nutritional ingredient promation  before  and after fermentation by SCOBY.

 

 

Author Response

1. D-Glucaric acid-1,4-lactone is one of most important bioactive compounds in Kombucha. It has increasing the immune function and reducing the risks of cancers, author should supplement some  information  about this issue.

D-saccharic acid-1,4-lactone has been included in the abstract (L11) and sections 1.6 (L407) and 1.7 (L412, L414-L418). Thank you for your valuable input.

2. All of the  Acetobacter,   Komagataeibacter was used as the prefix name,   please check the most popular name, which were used in literature.

This issue has been addressed throughout the sections, thank you.

3. Rooibos was used as tea base for Kombucha , it is a good idea , can author supplement some  information about nutritional ingredient promation  before  and after fermentation by SCOBY.

We would have loved to provide more information on rooibos as a tea base for kombucha production, but very little research has been done on it. As such, no information on the nutritional ingredients before and after fermentation by SCOBY is available.