Comprehensive Profiling of Coconut Oil Varieties: Fatty Acids Composition, Oxidative Stability, Bioactive Properties, and Sensory Attributes

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In general, the manuscript is interesting and scientifically sound. I have some comments:

 

Methods say TEAC “per litre,” whereas the Abstract, Figure 1 axis, and Results use mg TEAC/g; the Discussion also uses mg TEAC/kg once. Standardize to one unit. Write in lowercase letters the units written in Figure 1.

Please indicate whether sample turbidity/background at 515 nm was blank-corrected (oil in ethanol)

For GC, please include the oven temperature program, inlet and detector temps, carrier gas flow, split ratio, and identification criteria (RT matching window, MS ions if used for confirmation) 

Since oils diffuse poorly in agar, did you consider a positive control antibiotic/antifungal disc to verify plate sensitivity as well as a negative control solvent/disc?

Figure 3b is blurry, please adjust it properly

Section 2.2 requires more detailed information: purchase dates, lot/batch numbers, declared origins/processing, best-before dates, and storage conditions

Add details on panel recruitment and ethics/consent, blinding and randomization, serving temperature/portion size, palate cleansers, and whether panelists were trained. Likewise, statistical analysis is required for sensory results.

Comments on the Quality of English Language

Please correct: “Haemophillus” to Haemophilus (Table 2 header); “appearence” to appearance (Table 5/elsewhere); “CoO24” to Coco24 in Discussion; “Candida glabrata CCM 818” in Methods should match CCM 8185 in Table 2. Ensure organism names are italicized consistently.

Use a logical structure to harmonize tense (Methods: past tense; Results: past tense; Discussion: present perfect/present where general).

Author Response

Dear Editor,

One more, we are very grateful to the reviewers for their valuable comments and suggestions, which helped us to improve the quality of the manuscript.

The manuscript was carefully proof-read and the quality, as well as English language was improved throughout the manuscript. Replies to reviewers’ comments are listed below.

 

Reviewer #1

Comment 1: In general, the manuscript is interesting and scientifically sound.

Response 1: Thank you so much.

Comment 2: Methods say TEAC “per litre,” whereas the Abstract, Figure 1 axis, and Results use mg TEAC/g; the Discussion also uses mg TEAC/kg once. Standardize to one unit. Write in lowercase letters the units written in Figure 1.

Response 2: The unit was correct in all manuscript for correct form mg TEAC/kg.

Comment 3: Please indicate whether sample turbidity/background at 515 nm was blank-corrected (oil in ethanol).

Response 3: Yes as a blank oil was used in ethanol, we added this information to DPPH methodic.

Comment 4: For GC, please include the oven temperature program, inlet and detector temps, carrier gas flow, split ratio, and identification criteria (RT matching window, MS ions if used for confirmation).

Response 4: This information was added.

Comment 5: Since oils diffuse poorly in agar, did you consider a positive control antibiotic/antifungal disc to verify plate sensitivity as well as a negative control solvent/disc?

Response 5: The antimicrobial activity tested prof. Kačániová, who is expert in this area in our university, and she used methodic which she modified for oils and essential oils. When she developed this method many years ago, she used positive control chloramphenicol. So, to this study she used the methodic which was suitable and good for this, it was not experiment what will be…but exact conditions and method which work for these kinds of samples.

Comment 6: Figure 3b is blurry, please adjust it properly.

Response 6: Figure 3b was improved.

Comment 7: Section 2.2 requires more detailed information: purchase dates, lot/batch numbers, declared origins/processing, best-before dates, and storage conditions.

Response 7: This section was improved with all information.

Comment 8: Add details on panel recruitment and ethics/consent, blinding and randomization, serving temperature/portion size, palate cleansers, and whether panelists were trained. Likewise, statistical analysis is required for sensory results.

Response 8: We added information, and it is necessary to said that at the Slovak University of Agriculture, we are able to conduct and provide sensory evaluation of foods without the need for a special memorandum. In our Food Study Programs at Slovak University of Agriculture in Nitra, we offer a course titled "Sensory Evaluation of Food," in which both students and staff can participate in evaluating food samples and research products. These evaluations are conducted without requiring signatures or formal approvals. Our goal is to facilitate sensory assessments for individuals interested in contributing to food quality and research through voluntary participation. All conditions of evaluation are with accordance to Code of Ethics for Employees of the Slovak University of Agriculture in Nitra from 10.01.2022 and Code of Ethics for Students of the Slovak University of Agriculture in Nitra from 02.12.2021.

Both these codes were sent to redaction.

Sensory evaluation results were presented using radar (spider) graphs, which illustrated the summed scores from all evaluators for each sensory attribute. This visualization method was chosen for its effectiveness in representing multidimensional sensory data in a clear and comparative manner. While advanced statistical techniques can be applied, in this study radar graphs served as a practical and commonly accepted approach to interpret sensory differences. This method has been previously used without issues and is well-suited for communicating sensory profiles in a visually intuitive format

Comment 9: Please correct: “Haemophillus” to Haemophilus (Table 2 header); “appearence” to appearance (Table 5/elsewhere); “CoO24” to Coco24 in Discussion; “Candida glabrata CCM 818” in Methods should match CCM 8185 in Table 2. Ensure organism names are italicized consistently.

Response 9: All was corrected.

Comment 10: Use a logical structure to harmonize tense (Methods: past tense; Results: past tense; Discussion: present perfect/present where general).

Response 10: We improved it.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The latin names must be written in italic.

Numbers should be written as numbers, not as words. Use the SI system units where they should be used.

Section 2.3.1. is the color change from white to pink, or from transparent to pink?

If you are writing about using chemicals of certain chemical formulas in the manuscript, you must either use their names, or formulas, not mix them.

Nitrogen and hydrogen gasses must be written with 2 in subscript.

How were the pathogens chosen for the Antimicrobial assay? There is no logic behind combining these pathogens.

The antimicrobial assay is not described enough. How was it performed? Based on which method, etc.

The results section needs to have some description of the results, not just tables/figures.

Sections 3.3. and 3.4., the Tables need to be where they are mentioned, not on the next page.

Table 2 should be split into 2 tables, one for bacteria, and one for fungi.

How is table 4 after table 5 in the manuscript?

The abbreviations should be introduced on the first mention of the words that will be abbreviated, and then used throughout the manuscript. Please correct.

The entire discussion section must be rewritten, as it is currently written in a very confusing manner, where a lot is said, but nothing at all at the same time. You need to simplify it, and make clear what you want to point out.

The conclusion must be rewritten to be shorter and more concise, only focus on the main findings of your research.

 

Author Response

Dear Editor,

One more, we are very grateful to the reviewers for their valuable comments and suggestions, which helped us to improve the quality of the manuscript.

The manuscript was carefully proof-read and the quality, as well as English language was improved throughout the manuscript. Replies to reviewers’ comments are listed below.

 

Reviewer #2

Comment 1: The latin names must be written in italic.

Response 1: This part was corrected.

Comment 2: Numbers should be written as numbers, not as words. Use the SI system units where they should be used.

Response 2: This part was corrected.

Comment 3: Section 2.3.1. is the color change from white to pink, or from transparent to pink?

Response 3: This part was corrected from transparent to pink.

Comment 4: If you are writing about using chemicals of certain chemical formulas in the manuscript, you must either use their names, or formulas, not mix them.

Response 4: This part was corrected.

Comment 5: Nitrogen and hydrogen gasses must be written with 2 in subscript.

Response 5: This part was corrected.

Comment 6: How were the pathogens chosen for the antimicrobial assay? There is no logic behind combining these pathogens.

Response 6: The pathogens were selected by Prof. Kačániová, who is the microbiology specialist at our university. She chose those that were available in her laboratory. The selection was made in a systematic way to include Gram-negative bacteria, Gram-positive bacteria, and yeast. Therefore, the selection is logical.

Comment 7: The antimicrobial assay is not described enough. How was it performed? Based on which method, etc.

Response 7: The antimicrobial activity tested prof. Kačániová, who is expert in this area in our university, and she used methodic which she developed for oils and essential oils by herself. So, to this study she used the methodic which was suitable and good for this.

Comment 8: The results section needs to have some description of the results, not just tables/figures. All the subtitles in “Results Section” have a description.

Response 8: This part was improved.

Comment 9: Sections 3.3. and 3.4., the Tables need to be where they are mentioned, not on the next page.

Response 9: Corrected. Improved in the manuscript.

Comment 10: Table 2 should be split into 2 tables, one for bacteria, and one for fungi.

Response 10: Corrected. Division for bacteria and fungi is included in Table 2.

Comment 11: How is table 4 after table 5 in the manuscript?

Response 11: Corrected. Improved in the manuscript.

Comment 12: The abbreviations should be introduced on the first mention of the words that will be abbreviated, and then used throughout the manuscript. Please correct.

Response 12: Corrected.

Comment 13: The entire discussion section must be rewritten, as it is currently written in a very confusing manner, where a lot is said, but nothing at all at the same time. You need to simplify it, and make clear what you want to point out.

Response 13: Part discussion was written logically with comparing the results with other findings. Results were good described and interpreted. Anyway, all this part was improve.

Comment 14: The conclusion must be rewritten to be shorter and more concise, only focus on the main findings of your research.

Response 14: This part was improved.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors, the paper presents interesting information; however, some modifications are necessary: ​​

Abstract 
Line 50. Indicate the MIC values. 
Indicate the results of the statistical analysis for each result shown. 
Lines 54-59. I find this confusing; please rewrite it. 
Introduction 
Justify the study of coconut oils from the Slovakian market more clearly. The justification of the study is missing. 
Results 
The authors did not describe the results. In this section, describe the most relevant results in each evaluation and indicate the results of the statistical analyses for each result described. 
Discussion 
The results obtained are not described in this section. 
Line 344. Indicate which phenolic-rich oils have been detected in coconut oils. Indicate the antioxidant mechanism of these compounds. Line 352. Indicate the antioxidant mechanisms of action of the compounds mentioned. 
Lines 354-363. Explain how the aforementioned methods influence the presence of antioxidant compounds in coconut oils. 
Line 369. Explain how this structural characteristic of bacteria affects the antimicrobial activity of coconut oils. 
Line 372. Explain the proposed suggestion in detail. 
Lines 373-384. The aforementioned fatty acids are nonpolar in nature. Considering the nature of Gram-positive and Gram-negative bacterial structures, fatty acids would be more active in Gram-negative bacteria due to their polarity and thin peptidoglycan layer. How do you explain the results found?

Author Response

Dear Editor,

One more, we are very grateful to the reviewers for their valuable comments and suggestions, which helped us to improve the quality of the manuscript.

The manuscript was carefully proof-read and the quality, as well as English language was improved throughout the manuscript. Replies to reviewers’ comments are listed below.

 

 

Reviewer #3

Comment 1: Abstract Line 50. Indicate the MIC values. Indicate the results of the statistical analysis for each result shown. Lines 54-59. I find this confusing; please rewrite it.

Response 1: This part was corrected.

Comment 2: Introduction Justify the study of coconut oils from the Slovakian market more clearly. The justification of the study is missing.

Response 2: This part was improved.

Comment 3: Results The authors did not describe the results. In this section, describe the most relevant results in each evaluation and indicate the results of the statistical analyses for each result described.

Response 3: The short evaluation was added to this part.

Comment 4: Discussion The results obtained are not described in this section.

Response 4: Discussion was improved, and is very good prepared, all results are evaluated and compared with other findings.

Comment 5: Line 344. Indicate which phenolic-rich oils have been detected in coconut oils. Indicate the antioxidant mechanism of these compounds.

Response 5: This part was added.

Comment 6: Line 352. Indicate the antioxidant mechanisms of action of the compounds mentioned.

Response 6: This part was added.

Comment 7: Lines 354-363. Explain how the aforementioned methods influence the presence of antioxidant compounds in coconut oils.

Response 7: This part was added.

Comment 8: Line 369. Explain how this structural characteristic of bacteria affects the antimicrobial activity of coconut oils.

Response 8: This part was added.

Comment 9: Line 372. Explain the proposed suggestion in detail.

Response 9: This part was added.

Comment 10: Lines 373-384. The aforementioned fatty acids are nonpolar in nature. Considering the nature of Gram-positive and Gram-negative bacterial structures, fatty acids would be more active in Gram-negative bacteria due to their polarity and thin peptidoglycan layer. How do you explain the results found?  

Response 10: Our results showed that coconut oil inhibits both Gram-negative and Gram-positive bacteria. These findings are consistent with the known antimicrobial properties of medium-chain fatty acids, particularly lauric acid, found in coconut oil. The fatty acid’s ability to disrupt bacterial membranes, irrespective of the bacterial classification, can explain why coconut oil worked effectively against both typed of bacteria, even if reviewer 3 had a point about the relative ease of action in Gram-negative bacteria.

 

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I appreciate the clarifications provided by authors, however I have some comments:

Based on response to comment # 5, authors should properly discuss limitations of disc diffusion with oils, and the rationale used to justify the procedure that finally was employed.

For the Antioxidant assay, as DPPH preferentially measures hydrophilic antioxidants, any limitation should be mentioned for your study? 

Round excessively precise numbers (e.g., many values given to 3+ decimals) to 2 significant figures where appropriate and ensure SDs are consistent.

Please clarify if any data pretreatment was performed previous to PCA

 

 

Comments on the Quality of English Language

The manuscript needs careful English proofreading. Examples to fix: “In Slovak republic consumption of coconut oil started to be very popular, due to the health benefits, but exact studies about benefits as well as risks connected with coconut oil using missing in Slovakia.”. Please rewrite for clarity. Consider professional copy-editing.

Author Response

Dear Editor,

One more, we are very grateful to the reviewers for their valuable comments and suggestions, which helped us to improve the quality of the manuscript.

The manuscript was carefully proof-read and the quality, as well as English language was improved throughout the manuscript. Replies to reviewers’ comments are listed below.

 

Reviewer #1

Comment 1: appreciate the clarifications provided by authors, however I have some comments

Response 1: Thank you so much.

Comment 2: Based on response to comment # 5, authors should properly discuss limitations of disc diffusion with oils, and the rationale used to justify the procedure that finally was employed.

Response 2: All procedure for disc difussion method is described in detail in part methods, but we included information there that it was modified for this type of sample.

Comment 3: For the Antioxidant assay, as DPPH preferentially measures hydrophilic antioxidants, any limitation should be mentioned for your study? 

Response 3: Thank you, we appreciate your suggestion to address the limitation of the DPPH assay in detecting primarily hydrophilic antioxidants. We agree that DPPH is more sensitive to hydrophilic compounds, and as such, its use in this study might not fully capture the antioxidant potential of lipophilic compounds. We have added a note in the revised manuscript to acknowledge this limitation.

Comment 4: Round excessively precise numbers (e.g., many values given to 3+ decimals) to 2 significant figures where appropriate and ensure SDs are consistent.

Response 4: Thans for your suggestion. In direct response to your feedback regarding numerical precision, we have carefully revised the entire document. All excessively precise values have been rounded to two or three significant numbers where appropriate. Furthermore, we have standardized the presentation of all standard deviations to ensure complete consistency throughout the manuscript tables (Tables 1, 2, 3).

Comment 5: Please clarify if any data pretreatment was performed previous to PCA.

Response 5: Thank you for this important question. In response to your query, we performed data pretreatment prior to the Principal Component Analysis (PCA). The data was auto-scaled, meaning it was mean-centered and scaled to unit variance to ensure all variables were weighted equally in the analysis. This clarification has now been added to the “Statistical analysis“ (lines 227-229) section of the revised manuscript.

Comment 6: The manuscript needs careful English proofreading. Examples to fix: “In Slovak republic consumption of coconut oil started to be very popular, due to the health benefits, but exact studies about benefits as well as risks connected with coconut oil using missing in Slovakia.”. Please rewrite for clarity. Consider professional copy-editing.

Response 6: The English level was improved.

 

 

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

There is no logic in using all the available pathogens, you should be focused on the pathogens of a single source, be it skin, GI system, etc. This type of choosing makes no sense.

As i previously said, you must split the Table 2 into 2 separate tables. You cannot present both the antifungal and antibacterial activities in the same table. It will also be easier to read and understand the results.

The level of the English language is very low, and must be corrected.

 

 

Comments on the Quality of English Language

The level of the English language is very low, and it needs extensive editing.

 

Author Response

Dear Editor,

One more, we are very grateful to the reviewers for their valuable comments and suggestions, which helped us to improve the quality of the manuscript.

The manuscript was carefully proof-read and the quality, as well as English language was improved throughout the manuscript. Replies to reviewers’ comments are listed below.

 

Reviewer #2

Comment 1: There is no logic in using all the available pathogens, you should be focused on the pathogens of a single source, be it skin, GI system, etc. This type of choosing makes no sense.

Response 1: Thank you for your thoughtful feedback. As the authors of this study, we chose to work with microorganisms that were readily available to us and that we are most familiar with. Our aim was to include a broad range of microorganisms, specifically Gram-negative bacteria, Gram-positive bacteria, and yeast, to give a well-rounded perspective. We understand your concern and appreciate the opportunity to clarify our approach. Ultimately, we believe this selection aligns well with the objectives of our research, and we kindly ask that the review considers the authors' decision on the microorganism selection.

Comment 2: As i previously said, you must split the Table 2 into 2 separate tables. You cannot present both the antifungal and antibacterial activities in the same table. It will also be easier to read and understand the results.

Response 2: Thank you for this suggestion and for your continued guidance on improving the manuscript's clarity. We have followed your recommendation and have separated the data into two distinct tables. Table 2 now presents the antibacterial activity, and a new Table 3 presents the antifungal activity. We agree that this separation significantly enhances the readability and allows the reader to focus on each dataset more effectively. The revised manuscript with the split tables is included for your review.

Comment 3: The level of the English language is very low, and must be corrected.

Response 3: The level of English language was improved.

 

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

Dear authors. 

The manuscript was improved; however, the results could be described more precisely. I suggest indicating the statistical differences throughout the text, for example, (p<0.05 or p>0.05).

Author Response

One more, we are very grateful to the reviewers for their valuable comments and suggestions, which helped us to improve the quality of the manuscript.

The manuscript was carefully proof-read and the quality, as well as English language was improved throughout the manuscript. Replies to reviewers’ comments are listed below.

 

Reviewer #3

Comment 1: The manuscript was improved; however, the results could be described more precisely. I suggest indicating the statistical differences throughout the text, for example, (p<0.05 or p>0.05).

Response 1: Thank you for this valuable suggestion to enhance the precision of our results reporting. We have revised the manuscript to include the specific p-values (e.g., p < 0.05, p > 0.05) throughout the Results section wherever statistical differences are discussed (lines 359, 383, 409, 439, 465, 502, 510, 511, 523, 537, 542, 551, 632) of the improved manuscript). This clarification provides a more accurate representation of the significance levels for the reader of our manuscript.

 

Author Response File: Author Response.docx

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

I consider the manuscript is suitable for publication. I have other considerations:

Table 5 is dense. Consider showing only correlations above a threshold (e.g., |r|>0.5) or split the table into blocks (fatty acids vs sensory vs microbial).

Use consistent country name usage (“Slovak Republic” vs “Slovakia”), consistent use of abbreviations (e.g., VCO, CO) and define them on first use.

Author Response

Dear Editor,

One more, we are very grateful to the reviewers for their valuable comments and suggestions, which helped us to improve the quality of the manuscript.

 

Reviewer #1

Comment 1: I consider the manuscript suitable for publication. I have other considerations

Response 1: Thank you so much.

Comment 2: Table 5 is dense. Consider showing only correlations above a threshold (e.g., |r|>0.5) or split the table into blocks (fatty acids vs sensory vs microbial).

Response 2: Thank you for the suggestion. We agree that Table 5 is too dense. We eliminated dependent variables (i.e., Acid Number, C14:0, and Overall appearance) that showed correlations under 50% (|r|<0.5), and we kept the dependent variables that have at least one correlation above 50% between them.

Comment 3: Use consistent country name usage (“Slovak Republic” vs “Slovakia”), consistent use of abbreviations (e.g., VCO, CO) and define them on first use.

Response 3: This part was correct.

 

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Sending the entire manuscript in red letters makes it really hard to follow which changes have been performed for which reviewer, therefore, making it impossible to assess whether you have made changes in the text that were asked of you.

Author Response

Dear Editor,

One more, we are very grateful to the reviewers for their valuable comments and suggestions, which helped us to improve the quality of the manuscript.

 

Reviewer #2

Comment 1: Sending the entire manuscript in red letters makes it really hard to follow which changes have been performed for which reviewer, therefore, making it impossible to assess whether you have made changes in the text that were asked of you.

Response 1: Thank you, we provided all revisions like you want, we are sorry that text was all in red, but as you and other reviewers wrote, we improved English in all text. These all revision were done in previous round: Comment 1: There is no logic in using all the available pathogens, you should be focused on the pathogens of a single source, be it skin, GI system, etc. This type of choosing makes no sense.

Response 1: Thank you for your thoughtful feedback. As the authors of this study, we chose to work with microorganisms that were readily available to us and that we are most familiar with. Our aim was to include a broad range of microorganisms, specifically Gram-negative bacteria, Gram-positive bacteria, and yeast, to give a well-rounded perspective. We understand your concern and appreciate the opportunity to clarify our approach. Ultimately, we believe this selection aligns well with the objectives of our research, and we kindly ask that the review considers the authors' decision on the microorganism selection.

Comment 2: As I previously said, you must split the Table 2 into 2 separate tables. You cannot present both the antifungal and antibacterial activities in the same table. It will also be easier to read and understand the results.

Response 2: Thank you for this suggestion and for your continued guidance on improving the manuscript's clarity. We have followed your recommendation and have separated the data into two distinct tables. Table 2 now presents the antibacterial activity, and a new Table 3 presents the antifungal activity. We agree that this separation significantly enhances the readability and allows the reader to focus on each dataset more effectively. The revised manuscript with the split tables is included for your review.

Comment 3: The level of the English language is very low, and must be corrected.

Response 3: The level of English language was improved.

 

 

Author Response File: Author Response.docx