Modulating Coffee Fermentation Quality Using Microbial Inoculums from Coffee By-Products for Sustainable Practices in Smallholder Coffee Production

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors studied viability of lactic acid bacteria and yeast inoculums for coffee fermentation using coffee pulp and coffee fermentation wastewater as carbon source. The models for prediction of microbial growth depending on coffee pulp and wastewater concentrations as well as incubation time were developed. Moreover, effects of different treatment methods on sensory properties of coffee were studied. This work is quite interesting and most of the results are well presented however several points should be improved:

-LL38-42: There were two very similar sentences, please keep only one of them

-L70: Two similar sentences again. Please fix it.

“Сonversely, yeast produces aromatic esters that impart a distinct fruity aroma to 70 roasted coffee [18,19].”

“Yeast volatile metabolites, particularly aromatic esters, can partially remain after the 75 roasting process and contribute to the fruity and floral attributes of the roasted coffee”

-LL126-127: Please add “from” before “commercial yogurt”. Also replace “was” with “were”

-L168: How many replicates were used for “Coffee cup quality evaluation”? Did the taster evaluates sample one or several times? Please, clarify this.

-L243: Please replace “was” with “were”

-LL253-262: It is looks like extraneous information

-L291: Why did the authors not adjust initial pH in fermentation experiments? For example, pH ~ 4.0 does not seem to be appropriate for cultivation of Lactobacillus delbrueckii.   

LL467-472 and LL551-558: This sounds more like a literature review than a discussion of obtained results. Please fix it and similar cases in Discussion section.

L612: What is “CONCLUSION DE SENSORIAL”?

Table 4: Actually, there is almost no difference in sensory characteristics during control treatment and other treatments. So, what is the purpose of optimizing the microbial inoculums?

Figure 1a: there is misprint “UFC”, please correct it

Figure 3: it is required to visualize (e.g. by different colors) which points belong to a particular treatment type       

Author Response

Thank you for your valuable feedback and suggestions to improve our manuscript. We have carefully addressed all the comments and uploaded a point-by-point response document in Word format for your review.

We appreciate your time and effort in reviewing our work and look forward to your feedback.

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

 

 

This study developed an inoculum culture for semi-controlled coffee fermentation using lactic acid bacteria (LAB) and yeast, with coffee production by-products as carbon sources. The result showed the treatment could produce high sensory scores, particularly in balance, fragrance, and

acidity. The research seems interesting, but still contained the following problem:

1 title: Enhancing coffee fermentation make us confused, maybe should be enhance coffee fermentation quality or taste?

2 The author should provide a research route in the text to make the process clear, so that the reader know that the fermentation for the side-product is used to improve the produce quality.

 

3 The author used a lot of efforts to describe the effect of the microorganism, we know yeast and LAB generally could only use sugar, but the author failed to provide the composition of the raw materials. And we know enzyme is very important, did the author think of the enzyme?

 

4 The author said the utilization of the side product, how much CR and CWW is used in the study, we only see the microbes, so can author provide some mass balance analysis, is this technology a good one for side product utilization?

Author Response

Thank you for your valuable feedback and suggestions to improve our manuscript. We have carefully addressed all the comments and uploaded a point-by-point response document in Word format for your review.

We appreciate your time and effort in reviewing our work and look forward to your feedback.

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I suggest that after the corrections made by the authors, this article is suitable for publication in the Sustainability journal. 

Author Response

Dear Reviewer,

Thank you for your thoughtful review and positive feedback on our revised manuscript. We are delighted to hear that you find the article suitable for publication in Sustainability.

 

Your comments helped improve the quality of our work, and we truly appreciate the time and effort you put into reviewing our submission.

Best regards,
Luisa Fernanda Duque Buitrago
On behalf of the Author Team

Reviewer 2 Report

Comments and Suggestions for Authors

The author should provide a research roadmap, that is to say, provide a new figure about what is the main research content in the study. Currently the author only tried to describe the content and did not provide the figure. This should be in materials and methods part, not in the introduction. 

Author Response

Thank you for this suggestion. We now understand that you were requesting a research roadmap in the form of a figure. We regret the misunderstanding in our initial interpretation and appreciate your clarification.

To address this, we have created and added a figure in the Materials and Methods section, which outlines the key steps and main content of the study. 

We are sharing the final version of the manuscript, which includes this new figure, for your consideration.