Improvement of the Chemical Quality of Cachaça

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article titled “Improvement of the Chemical Quality of Brazilian Sugar Cane Spirits” presents an in-depth analysis of the chemical composition of sugarcane spirits and commercial cachaças. The study focuses on analyzing 531 cachaça samples to assess their compliance with the Brazilian legal standards for contaminants and volatile compounds, utilizing traditional analytical methods. The findings indicate that Brazilian producers have effectively adopted Good Manufacturing Practices (GMP) in the production process, leading to the standardization of distilled beverages and ensuring compliance with legislation, thus contributing to the high standardization within the beverage industry.

 

However, there are several areas where the quality of the current work could be enhanced:

 

1.       It is recommended to incorporate more recent studies into the literature review to provide a more comprehensive background. Additionally, in line 41, the mention of copper as previously discussed is inaccurate, as this topic was not addressed earlier in the introduction. A thorough review of the introduction is necessary to ensure consistency and clarity.

 

2.       The analytical methods used to validate the findings are not sufficiently detailed. Providing a more comprehensive explanation of the analysis would enhance the credibility and reproducibility of the results.

 

3.       The paper lacks a discussion on the limitations of the study. Addressing potential limitations and their implications for the results would offer a more balanced and critical perspective on the findings.

 

4.       Minor grammatical errors and incorrect phrasings are present throughout the paper. A meticulous proofreading process is recommended to improve the overall clarity and readability.

 

 

5.       Typographical Errors: There are a few typographical errors, such as the underline at “degree (°)” and other minor grammatical issues. These needs to be corrected to ensure the professional presentation of the work.

Comments on the Quality of English Language

The quality of the English language can be a little improved.

 

Author Response

Manuscript ID beverages-3152110

Improvement of the chemical quality of Cachaças

 

Dear Ms. Fifteen Hu,

 

We would like to thank you and the Reviewers for your comments concerning our manuscript submitted to Beverages Journal. All the comments and suggestions were profoundly insightful and enabled us to significantly improve the quality of our manuscript.

We are glad to let you know that all the comments were considered in the revised version of the manuscript with track changes presented herewith. In the following pages are our point-by-point responses to each of the comments in blue.

 

Reviewer comments to the Authors:

 

Reviewer #1

 

We would like to thank Reviewer #1 for the relevant comments and suggestions. We really appreciated them.

 

1. It is recommended to incorporate more recent studies into the literature review to provide a more comprehensive background. Additionally, in line 41, the mention of copper as previously discussed is inaccurate, as this topic was not addressed earlier in the introduction. A thorough review of the introduction is necessary to ensure consistency and clarity.

• We inform you that we have removed the term "as previously mentioned" in relation to copper, and replaced it with "for example" as a reference to the previous paragraph in which we mentioned the main contaminants (line 74). The introduction was also revised and new references were added to promote greater consistency and clarity, addressing the history of cachaça, the annual production volume and also its differences in relation to Rum, a drink internationally produced from sugar cane (lines 36 to 54).

 

2. The analytical methods used to validate the findings are not sufficiently detailed. Providing a more comprehensive explanation of the analysis would enhance the credibility and reproducibility of the results.

• The analysis methodologies were better detailed, especially in relation to obtaining the samples with the addition of the cachaça production flowchart (lines 99 to 103), the detailing of the methodology for quantifying the copper concentration in the samples (lines 142 to 149) and the addition of examples of GC-FID and GC-MS chromatograms in complementary materials (lines 449 to 464) with the aim of increasing the clarity of the study and the reproducibility of the results.

 

3. The paper lacks a discussion on the limitations of the study. Addressing potential limitations and their implications for the results would offer a more balanced and critical perspective on the findings.

• We appreciate suggestions regarding a more critical discussion of the results presented. We would like to emphasize that the analyses addressed in this article are of a global nature, aiming to understand the improvement of the main quality parameters of cachaça based on the main volatile compounds and contaminants. In order to make the understanding of the percentage metrics clearer, we prepared Table 3 (line 300) after the review, and only then show the comparison with previous studies. Regarding future studies, we will address other more detailed parameters such as esters and aldehydes in cachaça.

 

4. Minor grammatical errors and incorrect phrasings are present throughout the paper. A meticulous proofreading process is recommended to improve the overall clarity and readability.

• We regret the occurrence of grammatical errors and incorrect sentences throughout the text. We understand the importance of clear and accurate language in a renowned and highly regarded journal such as Beverages. Based on your suggestions, we carried out a meticulous review and correction of the entire manuscript.

 

5. Typographical Errors: There are a few typographical errors, such as the underline at “degree (°)” and other minor grammatical issues. These needs to be corrected to ensure the professional presentation of the work.

• We appreciate the suggestions made regarding typographical errors and inform you that we have observed them all carefully and made the necessary corrections throughout the manuscript.

We do expect to have made all the corrections in the manuscript based on the Reviewers’ recommendations and suggestions, which greatly contributed to improve the quality of our work. All the suggestions and comments were greatly appreciated and truly helped to improve the quality of our manuscript. We hope the revised version is now suitable for publication and reaches the high standards for publication in Beverages. We look forward to hearing from you soon.

 

Sincerely yours,

 

Amanda de Andrade Marcondes Pereira

Corresponding author

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The paper entitled: ``Improvement of the chemical quality of Brazilian Sugar Cane Spirits`` is of scientific importance, corresponds to the topic of the journal, but requires major changes.

Introduction

In the introduction I would point out some previous research on quality, technology or other important aspects regarding Brazilian cachaça. Also, in the title it would be indicated to include the term of cachaça.

The Highlights presented at the end of introduction sounds like a conclusion, not an introduction.

Methods

1.      2.2.3. More information about Cu determination are needed.

2.      a GC-MS and a GC-FID chromatogram for samples to be included either as additional material or in the methodology

3.      a technological scheme with  parameters regarding the process of cachaça obtaining would be useful, considering that in the discussions is about fermentation processes.

Results and discussion

The results and discussion section are presented more like a review. The data actually analyzed are presented only as a percentage of samples that comply with the legislation in force (figure 1), without providing the exact values ​​or at least the value range determined for each analyzed parameter. Considering the widely presented methodology (GC-MS, GC-FID), including method validations, it is expected to present quantifiable values, at least as an interval, considering the large number of analyses.

After the detailed description of the methodology, including calibration curves, LOQ, LOD, you expect the quantifiable values ​​obtained to be presented, not just sample percentages reported to the allowed limits.

Also, the other results presented in figure 2 and table 3 are interpretations of other results.

In conclusion, either the paper is structured as a review and then additional data will be provided in the introduction compared to other studies, or the article structure is kept, but actual data will be included that will be inserted at the beginning of the results and discussions section, as then the discussions related to other studies should be presented.

Author Response

Reviewer #2

 

We would like to thank Reviewer #2 for the relevant comments and suggestions. We really appreciated them.

 

Introduction

1. In the introduction I would point out some previous research on quality, technology or other important aspects regarding Brazilian cachaça. Also, in the title it would be indicated to include the term of cachaça.

The Highlights presented at the end of introduction sounds like a conclusion, not an introduction.

• The term cachaça was duly included in the title of the article, as was appropriately suggested after its review. In addition, we added some research related to technological, production and historical aspects of cachaça with the intention of improving the introduction of the manuscript (lines 36 to 54). The “Highlights” were also modified with the aim of presenting sentences corresponding to an introduction and not a conclusion, as requested (lines 85 to 92).

 

Methods

1. 2.3. More information about Cu determination are needed.

• The analysis methodologies were better detailed, especially in relation to detailing of the methodology for quantifying the copper concentration in the samples (lines 142 to 149), with the aim of increasing the clarity of the study and the reproducibility of the results.

 

2. a GC-MS and a GC-FID chromatogram for samples to be included either as additional material or in the methodology.

• Examples of GC-FID and GC-MS chromatograms were added in complementary materials (lines 449 to 464), as suggested by the reviewer.

 

3. a technological scheme with  parameters regarding the process of cachaçaobtaining would be useful, considering that in the discussions is about fermentation processes.

• We consider the inclusion of the technological scheme for the production of cachaça in the article to be very relevant for general understanding. Therefore, we made the adjustment requested in the review (as can be seen in line 99, Figure 1 of the methods):

 

 

Results and discussion

 

1. The results and discussion section are presented more like a review. The data actually analyzed are presented only as a percentage of samples that comply with the legislation in force (figure 1), without providing the exact values ​​or at least the value range determined for each analyzed parameter. Considering the widely presented methodology (GC-MS, GC-FID), including method validations, it is expected to present quantifiable values, at least as an interval, considering the large number of analyses. After the detailed description of the methodology, including calibration curves, LOQ, LOD, you expect the quantifiable values ​​obtained to be presented, not just sample percentages reported to the allowed limits. Also, the other results presented in figure 2 and table 3 are interpretations of other results.

 

• We thank Reviewer #2 for the comment and the opportunity to explain our work better. After the considerations, we consider that the article lacked deeper topics regarding the limits between the quantifications analyzed specifically for each compound. Therefore, before comparing with other previously published articles, we present a new table (Table 3) regarding the results. We hope that Table 3 (line 300) addresses the analyzed compounds in more depth. The discussion regarding the results presented (lines 275 to 292) also explores in more detail the concentrations found in each volatile and contaminant compound, in order to highlight that all of them are not only within the established parameters, but also, for the most part, present levels well below these limits:

 

In order to determine the distribution pattern of the concentration ranges of each sample, each compound analyzed was distributed into four concentration ranges (Table 3). From Table 3, it can be observed not only that the majority (>90%) of volatile compounds and contaminants comply with the current Brazilian legislation, but also that most are well below the established limits.

Regarding volatile compounds, 90.97% of the samples are in a range below 100 mg/100mL of anhydrous ethanol, 95.93% of aldehydes in acetic acid below 20 mg/100mL of anhydrous ethanol, 99.52% of esters below 100 mg/100mL of anhydrous ethanol, 81.57% with furfural below 1 mg/100mL of anhydrous ethanol,  88.05% of upper alcohols below 300 mg/100mL of anhydrous ethanol and 90.6% within the allowable range for the congener coefficient.

The contaminants analyzed in the present study, in turn, also showed satisfactory results for at least 90% of the samples analyzed. In relation to copper, 96.07% were in accordance with the limits (5 mg/L), with 75.62% below 2 mg/L. Ethyl carbamate presented 94.64% of the samples complying with the legislation (210 μg/L), with 83.14% below 150 μg/L. N-butyl alcohol, sec-butanol alcohol and methyl alcohol presented, respectively, 99.8%, 91.4% and 99% of the samples complying with the maximum limit of the legislation.

 

Table 3. Samples of cachaça within the concentration ranges of each compound analyzed and total number of samples of each compound.

Compound	Percentage of samples within concentration ranges				Samples in non-compliance with Brazilian legislation	Total number of Samples
Alcohol content at 20ºC ᵃ	<38	38-<42	42–<48	>49	<38 or >48	527
	5,88	17,49	76,66	0	5,88
Volatile congeners
Volatile acidity (acetic acid) ᵇ	<100	100–<150	150–<200	>200	>150	527
	90,97	5,73	1,19	2,11	3,3
Aldehydes (acetic aldehyde) ᵇ	<20	20–<30	30–<40	>40	>30	521
	95,93	3,07	0,58	0,42	1
Esters (ethyl acetate) ᵇ	<100	100–<200	200–<300	>300	>200	521
	99,52	0,38	0,1	0	0,1
Furfural ᵇ	<1	1–<5	5–<10	>10	>5	521
	81,57	17,43	0,62	0,38	1
Higher alcohols ᵇ	<300	300–<360	360–<420	>420	>360	522
	88,05	7,85	2,18	1,92	4,1
Coefficient of congeners ᵇ	<200	200–<650	650–<700	>700	<200 or >650	521
	8,44	90,6	0,19	0,77	9,4
Contaminants
Copper ᶜ	<2	2–<5	5–<7	>7	>5	484
	75,62	20,45	1,24	2,69	3,93
Ethyl-Carbamate ᵈ	<150	150–<210	210–<300	>300	>210	391
	83,14	11,5	2,04	3,32	5,37
N-butyl alcohol ᵇ	<1	1–<3	3–<5	>5	< 3	521
	98,46	1,34	0,2	0	0,2
Alcohol sec-butanol ᵇ	<5	5–<10	10–<20	>20	< 10	521
	86,41	4,99	1,7	6,9	8,6
Methyl alcohol ᵇ	<10	10–<20	20–<30	>30	< 20	521
	96,7	2,3	0,81	0,19	1

 

 

 

ᵃ	%ethanol (v/v) a 20 °C.
ᵇ	mg/100mL of anhydrous ethanol.
ᶜ	mg/L.
ᵈ	μg/L.

 

Source: Developed by the author.

 

 

 

 

Esperamos ter feito todas as correções no manuscrito com base nas recomendações e sugestões dos Revisores, o que contribuiu muito para melhorar a qualidade do nosso trabalho. Todas as sugestões e comentários foram muito apreciados e realmente ajudaram a melhorar a qualidade do nosso manuscrito. Esperamos que a versão revisada agora seja adequada para publicação e atinja os altos padrões de publicação em Bebidas. Estamos ansiosos para ouvir de você em breve.

 

Atenciosamente

 

Amanda de Andrade Marcondes Pereira

Autor correspondente

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I have reviewed the revised version of the manuscript and noted that the authors have adequately addressed all the comments.

 

Reviewer 2 Report

Comments and Suggestions for Authors

The authors respected the reviewer requirements.