Continuous Primary Beer Fermentation with Yeast Immobilized in Alginate–Chitosan Microcapsules with a Liquid Core

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The authors conducted a research regarding a continuous main beer fermentation with yeast immobilized in 2 alginate-chitosan microcapsules with a liquid core.

Materials and methods:

Line 71: Saccharomyces pastorianus should be in italic

Wort preparation: Please explain how did you dilute the wort. How did you prepare the water for dilution? Volume of prepared wort?

"The column was sterilized with desinfectants"- please explain the disinfectants agents. 

Was this experiment done in parallel? Or just once? It seems that this is a very small amount of wort/beer to conclude anything.

You mention "main beer fermentation" in the title. Does it mean primary fermentation? Because in Results and discussion you mention main beer parameters. It is unclear what do you mean by main. Please elaborate. 

Conclusion: "However, the beer produced in a laboratory scale was with flavor profile comparable to the flavor profile of two commercial beers..." This is true, you have achieved somewhat similar flavor profile. However, the statistical analysis is missing. There is no statistical proof for your claim, Please add statistical analysis. This should be done for all results.  Otherwise, what is the point of this paper? You did not confirm that there is (or is not) a significant statistical difference between the green and final beer. 

 

 

Comments on the Quality of English Language

moderate corrections. 

Author Response

Dear Reviewer,

Thank you very much for spending your time reading our manuscript! Please, see the attachments for answers to your remarks.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The paper entitled “Continuous main beer fermentation with yeast immobilized in alginate-chitosan microcapsules with a liquid core” provides data for the possibility of producing beer by using yeast immobilized in polymeric matrix.

 The aims of the study are clearly expressed.

The experimental program is described that, with some corrections, it can be applied.

The obtained results are concise, presented and discussed.

Conclusions are drawn according to the obtained data.

The authors will find bellow some corrections and adjustments that should be addressed.

General remarks

-          The manuscript should be carefully read in order to avoid the grammar issues occurred.

-          All the Latin names should be written with italic letters.

 

Specific comments

-          2. Materials and Methods

o   A subsection dedicated to the reagents used in the experiments (with details about their purity, providers, concentrations etc.) should be added.

-          2.3. Immobilization procedure

o   The procedure was optimized? Were other parameters (concentrations, time etc.) tested? With what results?

-          2.6. Analytical methods

o   What were the conditions used for vicinal diketones measurement on UV-VIS spectrophotometer?

-          The microcapsules are completely destroyed in the fermentation process?

-          It is recommended to add a comparison with studies about the immobilization of the yeast on other types of carriers, if they are available.

-          The acceptability of a beverage such as beer should be also evaluated by the final consumers? Were tests conducted in this direction? With what results?

-          The proposed laboratory technological regime can be scaled up in order to be industrially viable? Where tests realized in this direction? With what results?

Comments on the Quality of English Language

Moderate editing of English language required.

Author Response

Dear Reviewer,

Thank you very much for spending your time to read our manuscript! Please, see the attachment for the answers of your remarks.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors provided major corrections, however, the statistical analysis was not described as should be (no p-value or software), and in tables and figures not a single mark has been implemented to see the statistical difference. I suggest that the authors seek help from a statistical expert if they do not know how to acknowledge the statistical difference between samples. Statistical analysis should also be involved in the discussion.

Also, the volume of the prepared wort was not stated. 

Please implement these changes.

Author Response

Please, see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The paper entitled “Continuous main beer fermentation with yeast immobilized in alginate-chitosan microcapsules with a liquid core” (with title updated as “Continuous primary beer fermentation with yeast immobilized in alginate-chitosan microcapsules with a liquid core”) provides data for the possibility of producing beer by using yeast immobilized in polymeric matrix.

 

I congratulate the authors for taking into account the suggestions of the reviewers and for their efforts in bringing the necessary clarifications and making the requested changes. The work is much improved compared to the initial version.

Author Response

Please, see the attachment

Author Response File: Author Response.docx