From Hydrothermal Extraction to Catalytic Conversion: Mesoporous ZrO2-Assisted Valorization of Wheat Bran Sugars and Polysaccharides
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis is an interesting research focused on the valorisation of wheat bran to important platform molecules. The paper's formatting and grammar need improvement. The section of the manuscript on the catalytic results is very weak and needs major revision. The results should be expressed as the conversion of substrate and selectivity/yield of different products not in mass ratios or ratios of the areas of the peaks. Detailed comments can be found below:
Introduction
“is projected to 37 reach 18.8 Mt for the 2024/25”- “is projected” refers to future events, and since we are already in 2026, this sentence does not make much sense. The authors should check te actal production in 2025 and update the introduction
Line 42-glycolic acid and lactic acid are not polymers
Line 113-efficiency in extracting…
Line 138, 293, 294-formatting
Line 145-font format
Line 256-the tense moves from past to present and later past again. One grammatical tense should be selected and maintained throughout the manuscript. This should be verified in the whole manuscript, because there is a mix of tenses in most of the paragraphs.
Line 277-repetition
TEM images and the caption need to be formatted. The scale bar should be placed in the bottom right corner of the images. The scale bar colour can be changed to white to improve readability on a dark background.
Figure 3: A scale bar is coming out of the image.
Line 411- The authours claim “hemicellulose is more ready hydrolyzed and are soluble in aqueous solutions”-This statement suggests that hemicellulose is soluable in water. However, according to the scientific literature, hemicellulose is generally insoluble in water, especially plant-derived hemicellulose. Only some fractions of hemicellulose can be partially soluable in hot water or in the presence of alkali or acidic catalyst. -This i salso confimed by the results presented by the authors were they observed more C6 sugars after hydrolysis under milder reaction conditions, which shows the stability of hemicellulose vrs starch. Correct this part of the text in the manuscript.
Line 489-format
In catalysis, we normally compare the results based on the conversion, selectivty and yield, not base on the mass ratios. The authors should present the concentrations of the C6 and C5 sugars obtained, not the ratios of the peak areas. This can be calculated based on the moles of carbon present in the substrate and in the final solution.The selectivity to C5 And C6 should be also calculated for both extracts. Also the concentration of side products and selectivity to these products should be calculated.
The catalytic results obtained should be compared to other the results obtained by other authors using “real biomass” substrates and ZrO2 catalyst for hydrolysis.
It’s not clear which acid properties of the catalyst were responsible for the catalytic results, as the testing was done with only one catalyst and the authors did not present a blank reaction. The conclusions have to be based on the results obtained, not only on the literature finding. The improvement in hydrolysis with the addition of the catalyst is not shown in this work.
The reaction pathway proposed is base on the literature not on the actual results obtained.The authors ementioned that the concentration of the sugars and products was followed in time but they do not present these results. Why is that?Mass balance should be also added in order to estimate the amounts of insoluable products/humin and gas phase products in both methods.a
Comments on the Quality of English LanguageThe authors mix present and past tense when describing their results, which should be corrected.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments and Suggestions for Authorssee attached file
Comments for author File: 
Comments.pdf
The quality of the English language is not sufficient for publication in its current form, as numerous grammatical inaccuracies, incorrect verb forms (e.g., “leaded” instead of “led”) and non-native expressions are present throughout the text. In several sections, sentence structure is unclear and overly complex, reducing readability and fluency, and key scientific verbs are often used imprecisely, leading to ambiguous or weak statements.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript has been sufficiently improved and can be published after minor revision of language and formatting.
Author Response
Reviewer #1
The manuscript has been sufficiently improved and can be published after minor revision of language and formatting.
Response:
We would like to thank the reviewer for the positive evaluation of our revised manuscript and for indicating that minor language and formatting revisions were required.
In response, the manuscript has been carefully reviewed once again, and minor corrections related to language clarity, grammar, and formatting have been implemented throughout the text. For the reviewer’s convenience, all changes introduced in this second revision have been highlighted in gray in the updated version of the manuscript.
We believe that these final modifications have further improved the readability and overall presentation of the work.
Reviewer 2 Report
Comments and Suggestions for AuthorsGeneral Assessment
The authors have satisfactorily addressed the major comments raised during the previous review, leading to a substantial improvement of the manuscript. The study is now scientifically sound, well-organized, and suitable for publication in Surfaces following some targeted revisions to improve conciseness and formatting.
Minor Revisions
The heading for Section 3.3.2 appears twice (lines 500 and 549). Please verify and correct the section numbering and layout throughout the entire document.
Perform a final proofreading to correct minor grammatical issues and shorten overly long sentences, particularly in the Results and Discussion section.
Section 3.3: Sections 3.3.1 and 3.3.2 currently contain significant redundancies. The text frequently reiterates numerical values already presented in Tables 2–5 without providing sufficient comparative interpretation.
I recommend shortening Section 3.3.1 by focusing on general trends and the comparison between HE-MW and HE-CH, rather than mirroring the tabular data in prose.
Author Response
Reviewer #2
The authors have satisfactorily addressed the major comments raised during the previous review, leading to a substantial improvement of the manuscript. The study is now scientifically sound, well-organized, and suitable for publication in Surfaces following some targeted revisions to improve conciseness and formatting.
Response:
We sincerely thank the reviewer for the positive evaluation of our revised manuscript and for recognizing the substantial improvements achieved after addressing the previous comments.
Following this recommendation, the manuscript has been carefully revised once again to improve conciseness and formatting. Minor language refinements, stylistic adjustments, and formatting corrections have been implemented throughout the text to enhance clarity and readability. All these final modifications have been highlighted in gray in the revised version of the manuscript for the reviewer’s convenience.
We believe that these final adjustments have further strengthened the presentation and overall quality of the work, and we greatly appreciate the reviewer’s constructive feedback throughout the evaluation process.
Minor Revisions
- The heading for Section 3.3.2 appears twice (lines 500 and 549). Please verify and correct the section numbering and layout throughout the entire document.
Response:
We thank the reviewer for pointing out this formatting issue. We have carefully verified the manuscript and corrected the duplicated heading for Section 3.3.2. In addition, the section numbering and overall layout have been thoroughly checked and adjusted throughout the entire document to ensure consistency and accuracy. All these corrections have been incorporated into the revised version of the manuscript and highlighted accordingly.
- Perform a final proofreading to correct minor grammatical issues and shorten overly long sentences, particularly in the Results and Discussion section.
Response:
Thank you for this suggestion. The manuscript has been carefully proofread to correct minor grammatical issues and improve conciseness, particularly in the Results and Discussion section. All corresponding changes have been highlighted in gray in the revised version.
- Section 3.3: Sections 3.3.1 and 3.3.2 currently contain significant redundancies. The text frequently reiterates numerical values already presented in Tables 2–5 without providing sufficient comparative interpretation.
I recommend shortening Section 3.3.1 by focusing on general trends and the comparison between HE-MW and HE-CH, rather than mirroring the tabular data in prose.
Response:
We sincerely thank the reviewer for this constructive comment and for the positive evaluation of the overall quality of the manuscript. Sections 3.3.1 and 3.3.2 have been carefully revised to improve conciseness, clarity, and readability. The text has been substantially shortened by eliminating redundancies and avoiding the repetition of numerical values already presented in Tables 2–5. Instead, the revised sections now focus on the interpretation of general trends, comparative analysis between conventional and microwave-assisted extraction, and the discussion of extraction selectivity and sugar stability. In particular, the revised text emphasizes: (i) the comparative performance of HE-MW versus HE-CH conditions, (ii) the preferential extraction of hemicellulosic (C5) sugars, (iii) the predominance of bound sugars over free sugars, and (iv) the absence of degradation products under the studied mild conditions.
These modifications significantly improve the discussion by strengthening the analytical interpretation of the results while avoiding duplication of tabulated data. All changes have been highlighted in gray in the revised manuscript for the reviewer’s convenience.
We believe that these revisions fully address the reviewer’s concerns and further enhance the clarity and scientific quality of the manuscript.
