Valorization of Mexican Rambutan Peel through the Recovery of Ellagic Acid via Solid-State Fermentation Using a Yeast

Round 1

Reviewer 1 Report

The abstract is very short, add some numerical data, clear the aim and hypothesis of your study, introduction don't include all topic adjectives, materials and methods, pay attention for detaling all methods, providing the origin and model of all devices, also enhance the presentation of your results all tables and figures need to be enhanced, discussion is old need to be updated and references dont follow the journal instruction

 

revise by an expert with language Certificate

 

Author Response

Reviewer 1

Comments and Suggestions for Authors

The abstract is very short, add some numerical data, clear the aim and hypothesis of your study, introduction don't include all topic adjectives, materials and methods, pay attention for detaling all methods, providing the origin and model of all devices, also enhance the presentation of your results all tables and figures need to be enhanced, discussion is old need to be updated and references dont follow the journal instruction

 R= The abstract was modified. The devices used in the materials and methods section was given their origin and model. Tables and figures were modified. In the discussion section, I tried to discuss with papers related to the obtained and identified ellagic acid from various sources and how they obtain it (solid-state fermentation, submerged fermentation, ultrasound/microwave, conventional techniques). Compared to these authors, in this work a higher concentration of ellagic acid was obtained using Mexican rambutan peel by solid-state fermentation. The references was corrected.

 

 

 

Comments on the Quality of English Language

revise by an expert with language Certificate

R= English language was reviewed and corrected.

Reviewer 2 Report

Rosa-Esteban et al. presents an article ‘‘Valorization of Mexican rambutan peel through the recovery of ellagic acid by solid-state fermentation using a yeast’’. This is not exactly a new idea, as seen by previous studies on this peel (e.g., Cerda-Cejudo et al. https://doi.org/10.1016/j.fbp.2022.05.001), except for the fact that the yeast used may be a new one. Based on my assessment, there are some points in this draft that needs to be improved. The detailed comments are as follows;

MAJOR POINTS

1. Abstract

L13-14: This sentence looks like a conclusion. Please rewrite.  

L17: Which compounds?

L17-21: You need to define abbreviations EA and HPLC/ESI/MS at first use.

L22-23: But this has been shown before. Is the use of another yeast giving better EA yields?

 2. Introduction

L61-73: Some studies have done something like this.  

Cerda-Cejudo et al. (2022) https://doi.org/10.1016/j.fbp.2022.05.001

3. Methods

L136-137: The statement is hanging.

L146: 400 μL >> pipetted 400 μL i.e., avoid starting sentences with numbers. Correct these in L153, L180, e.t.c.

L148: I find it hard to believe that the curve with gallic acid stretch upto 500 ppm. Do the authors mean 50 ppm?

L203: negative mode [M-H]-1 >> negative ion mode, [M-H]^-

4. Conclusion  

Needs to be revised. Care should be taken to keep ‘‘S. cerevisiae’’ italicized throughout the document.

Minor fixes required

Author Response

Reviewer 2

Comments and Suggestions for Authors

Rosa-Esteban et al. presents an article ‘‘Valorization of Mexican rambutan peel through the recovery of ellagic acid by solid-state fermentation using a yeast’’. This is not exactly a new idea, as seen by previous studies on this peel (e.g., Cerda-Cejudo et al. https://doi.org/10.1016/j.fbp.2022.05.001), except for the fact that the yeast used may be a new one. Based on my assessment, there are some points in this draft that needs to be improved. The detailed comments are as follows;

MAJOR POINTS

1. Abstract

L13-14: This sentence looks like a conclusion. Please rewrite.  

R= The commented was attended

L17: Which compounds?

R= Ellagic acid, geraniin and corilagin.

L17-21: You need to define abbreviations EA and HPLC/ESI/MS at first use.

R= The comment was attended.

L22-23: But this has been shown before. Is the use of another yeast giving better EA yields?

R= The accumulation of ellagic acid by S.cerevisiae in Mexican rambutan peel has not been reported in the literature in comparison to that reported by Cerda-Cejudo et al., 2022 where Aspergillus niger GH1 was used for the accumulation of the same compound. In this study the yeast S. cerevisiae obtained a higher accumulation compared to a fungus.

2. Introduction

L61-73: Some studies have done something like this.  

Cerda-Cejudo et al. (2022) https://doi.org/10.1016/j.fbp.2022.05.001

3. Methods

L136-137: The statement is hanging.

R= The commented was attended.

L146: 400 μL >> pipetted 400 μL i.e., avoid starting sentences with numbers. Correct these in L153, L180, e.t.c.

R= The commented was attended.

L148: I find it hard to believe that the curve with gallic acid stretch upto 500 ppm. Do the authors mean 50 ppm?

R= The gallic acid curve was prepared from 0 to 500 ppm

L203: negative mode [M-H]-1 >> negative ion mode, [M-H]^-

R= The commented was attended.

4. Conclusion  

Needs to be revised. Care should be taken to keep ‘‘S. cerevisiae’’ italicized throughout the document.

R= The commented was attended.

Comments on the Quality of English Language

Minor fixes required

R= English language was reviewed and corrected.

Reviewer 3 Report

Valdes and coworkers report a solid state fermentation of rambutan peel for the isolation of ellagic acid. This is an important molecule with a wide range of biological activities. The authors circumvent common drawbacks of extraction methodologies by developing a fermentation procedure using yeast. Importantly the authors were able to obtain 136 mg/g of ellagic acid after 48h, and observe the concomitant reduction of geraniin and corilagin. The work is timely and of interest and I believe it merits publication in this journal. However, some minor issues should be addressed, such as Figure 4 where the authors attribute numbers to the chromatogram peaks. This numbers correspond to different compounds, which may generate confusion. I suggest attributing a number to each compound so that the figure is clearer. Another suggestion is to further prove that in fact the yeast is converting geraniin and corilagin to ellagic acid, the authors may incubate a media with the natural products (instead of the rambutan peel) and observe the formation of elagic acid.

The manuscript may benefit from an overal proofcheck concerning the quality of english.

Author Response

Reviewer 3

Comments and Suggestions for Authors

Valdes and coworkers report a solid state fermentation of rambutan peel for the isolation of ellagic acid. This is an important molecule with a wide range of biological activities. The authors circumvent common drawbacks of extraction methodologies by developing a fermentation procedure using yeast. Importantly the authors were able to obtain 136 mg/g of ellagic acid after 48h, and observe the concomitant reduction of geraniin and corilagin. The work is timely and of interest and I believe it merits publication in this journal. However, some minor issues should be addressed, such as Figure 4 where the authors attribute numbers to the chromatogram peaks. This numbers correspond to different compounds, which may generate confusion. I suggest attributing a number to each compound so that the figure is clearer. Another suggestion is to further prove that in fact the yeast is converting geraniin and corilagin to ellagic acid, the authors may incubate a media with the natural products (instead of the rambutan peel) and observe the formation of elagic acid.

R= Thank you for your comments. The figure 4 was modified and found in the document.

Comments on the Quality of English Language

The manuscript may benefit from an overal proofcheck concerning the quality of english.

R= English language was reviewed and corrected.

Round 2

Reviewer 1 Report

The abstract was enhanced compared to the last version, but calculate the content of ellagitannin before and after the fermentation process

The introduction is still short, enrich with your study objectives with recent citations

Enhance the resolution of Figures 2 and 3

Enhance the presentation of table 4

 

Adjust the citation format in discussion and enhance with recent citations up to 2023

English certificate 

 

Author Response

Reviewer 1

Comments and Suggestions for Authors

The abstract was enhanced compared to the last version, but calculate the content of ellagitannin before and after the fermentation process

R= The content of ellagitannins, geraniin and corilagin before the fermentation process are found in section 3.3. Solid-state fermentation after the figure 1.

 

The introduction is still short, enrich with your study objectives with recent citations

R= The commented was attended

 

Enhance the resolution of Figures 2 and 3

R= The figures were modified

 

Enhance the presentation of table 4

R= Table 4 was modified

 

 

Adjust the citation format in discussion and enhance with recent citations up to 2023

R= The commented was attended. There are few recent works that have worked with rambutan peel implemented as support in a SSF.

 

 

Comments on the Quality of English Language

English certificate

R= Attended. English was reviewed and edited by a native English speaker.

Author Response File: Author Response.pdf

Round 3

Reviewer 1 Report

Congratulation, Now can be accepted in Fermentation

 

Minor correction in proof