Chitin-Derived Silver Nanoparticles for Enhanced Food Preservation: Synthesis, Characterization, and Antimicrobial Potential

Round 1

Reviewer 1 Report

1.     Include the UV spec for both extracted chitin

2.     Same Chitin is extracted from fish and crab. But, How the FTIR results shown different vibrational spectrum? Why?

3.     Need NMR studies confirmation of both chitin. Also compare with standard chitin

4.     Include better TEM images for both synthesised chitin-AgNPs

5.     Include the Zeta potential analysis data for both synthesised chitin-AgNPs (To know the stability)

6.     Include the results for hemolytic assay

7.     Include the plates images of Antimicrobial Activity of Chitin Film

8.     For testing Self-life period of chitin nanoparticle in C. annuum and. S. lycopersicum. Author need to check for triplet in C. annuum and. S. lycopersicum

9.     Correct the grammatical errors throughout the manuscript. The manuscript needs to be completely and thoroughly revised for both English and scientific style by a professional scientific reviewer. The meaning and consistency of each sentence should be double-checked.

10.  Check Superscript and Subscript in whole manuscript

Yes

Author Response

Dear Editor and reviewers,

We sincerely thank you for your comments on our manuscript entitled “Chitin-Derived Silver Nanoparticles for Enhanced Food Preservation: Synthesis, Characterization, and Antimicrobial Potential”. These comments are all valuable and helpful for us to revise and to improve our manuscript. We have evaluated the comments carefully and have made the necessary corrections. We hope this will meet with your approval. Revised portions are marked in the manuscript, and the main corrections and the response to reviewer’s comments are listed below.

Reviewer -1

1. Include the UV spec for both extracted chitin

As per the reviewer's suggestion, the UV-Vis spectrum of chitin has been included in the manuscript.

2. Chitin is extracted from fish and crab. But, How do the FTIR results show different vibrational spectra? Why?

The distinct vibrational spectra observed in the FTIR analysis of chitin extracted from M. ayliffe shells and P. sanguinolentus exoskeleton stem from inherent structural and compositional variations within the chitin obtained from different biological sources. Chitin, as a polymer, is susceptible to differences in its molecular arrangement, degree of crystallinity, and the presence of impurities based on its biological origin. Structural disparities such as chain arrangement, degree of polymerization, and possible chemical modifications contribute to the differences in the observed FTIR peaks. Furthermore, variations in the degree of acetylation, impacting the number of acetyl groups present within the chitin polymer, play a role in the differing vibrational spectra. Even subtle differences in sample preparation methods or the crystalline nature of the chitin samples can significantly influence the FTIR analysis, leading to distinct peaks in the spectra. These nuanced disparities, despite the commonality of chitin as a polymer, highlight the sensitivity of FTIR to even minor structural variations, illustrating the uniqueness of chitin derived from diverse biological sources.

3. Need NMR studies confirmation of both chitin. Also compare with standard chitin

This study was a pilot study for examining the food preservative properties of chitin derived from seafood processing waste. Further analysis, including NMR studies and comparison with standard chitin, will be conducted in future studies.

4. Include better TEM images for both synthesized chitin-AgNPs

As per the reviewer's suggestion, the TEM images have been enhanced.

5. Include the Zeta potential analysis data for both synthesized chitin-AgNPs (To understand stability)

The Zeta potential of the chitin has been added to the manuscript as per the reviewer's suggestion to assess the stability of both synthesized chitin-AgNPs.

6. Include the results for the hemolytic assay

The results for the hemolytic assay have been added to the manuscript as per the reviewer's suggestion.

7. Include images of the Antimicrobial Activity of Chitin Film

Figure -5; Images of the plates showing the antimicrobial activity of the chitin film have been added to the manuscript as suggested by the reviewer.

8. For testing the Shelf-life period of chitin nanoparticles in C. annuum and S. lycopersicum. Authors need to check for triplicates in both C. annuum and S. lycopersicum

We would like to inform that triplet experiments were performed for determining the shelf-life period of chitin nanoparticles in C. annuum and S. lycopersicum. The findings suggest that these nanoparticles hold promise for enhanced food preservation against bacterial infections.

9. Correct the grammatical errors throughout the manuscript. The manuscript needs to be thoroughly revised for both English and scientific style by a professional scientific reviewer. The meaning and consistency of each sentence should be double-checked.

The manuscript is revised and undergone comprehensive editing by a professional scientific reviewer to ensure correct grammatical errors and ensure consistency in both scientific and English writing styles. Each sentence's meaning and consistency should be double-checked.

10. Check Superscripts and Subscripts throughout the manuscript

The correct use of superscripts and subscripts throughout the entire manuscript for accuracy is verify and ensured.

Reviewer 2 Report

Please consider the attached document.

Comments for author File: Comments.pdf

Author Response

Dear Editor and reviewers,

We sincerely thank you for your comments on our manuscript entitled “Chitin-Derived Silver Nanoparticles for Enhanced Food Preservation: Synthesis, Characterization, and Antimicrobial Potential”. These comments are all valuable and helpful for us to revise and to improve our manuscript. We have evaluated the comments carefully and have made the necessary corrections. We hope this will meet with your approval. Revised portions are marked in the manuscript, and the main corrections and the response to reviewer’s comments are listed below.

Reviewer -2

Broader comments:

a. The use of natural sources of chitin to produce food preservatives may be relevant to consumers. However, the authors do not address the main challenges of this field regarding the reproducibility of natural matrices in terms of chitin composition and production yield.

Acknowledging the potential variability in chitin composition and yield from natural matrices is crucial. We recognize that natural sources may exhibit variability, and our study has limitations in ensuring absolute consistency in chitin composition and yield. We plan to address this in future research by exploring methods to standardize the extraction process and better understand the implications of varying chitin compositions on the final product's effectiveness. This would contribute to improved reproducibility and consistency.

b. The silver nanoparticles and the composite films developed were not characterized in terms of stability which may hamper their use as food preservatives.

We understand the importance of characterizing the stability of the silver nanoparticles and composite films. In our future work, we aim to conduct comprehensive studies on the long-term stability of these materials under various storage conditions to ensure their suitability as food preservatives. This will involve assessing potential changes in their antimicrobial efficacy over time. Including this data will strengthen the potential application of these materials in food preservation.

c. Silver nanoparticles are known to display antimicrobial efficacy, but the authors did not characterize the effect of uncoated nanoparticles against Vibrio Spp.

The manuscript's focus was on exploring the enhanced antimicrobial potential of chitin-coated silver nanoparticles. However, we acknowledge the importance of studying the antimicrobial activity of uncoated nanoparticles against Vibrio Spp. In future studies, we intend to include this data to provide a more comprehensive understanding of the role of chitin in enhancing the antimicrobial effects of silver nanoparticles.

d. The manuscript contains various repeated sections paragraphs both in Results and Discussion sections. Moreover, the materials and methods lacks details to allow the repetition of the experiments by peers. Furthermore, Figures, Tables and the corresponding captions may be updated to improve clarity for the readers.

We acknowledge the need to revise the manuscript to eliminate repetitive paragraphs in the Results and Discussion sections to enhance clarity. Additionally, we plan to provide more detailed descriptions in the Materials and Methods section for better replicability by peers. Updating figures, tables, and their captions to offer a clearer understanding of the research findings is also a priority to improve the manuscript's clarity and readability.

As the author, I am committed to addressing these points in future research and manuscript revisions to enhance the quality, ethics, and comprehensiveness of the work. Thank you for bringing these important aspects to our attention.

1. Sections 2.2, 2.3, 2.4, 2.5.3: detailed information on the parameters used to perform the experiments must be provided.

As per the reviewer suggestion, the detailed methodology is provided in the manuscript

2. Section 2.7: Detailed and quantitative information on the application of the samples on fresh food products must be provided.

As per the reviewer suggestions, detailed methodology is provided in the manuscript.

3. Line 181-184: repeated information.

As per the reviewer suggestion, the repeated sentences were removed. 

4. Figure 2, 3, 5 and 6: scale bar is missing. Please include.

As per the reviewer suggestion, the scale bar is added.

5. Figure 4: Please specify the meaning of the legends displayed in the graphs. The absorbance values displayed in the graphs are too high. Have the authors considered to dilute the samples?

As per the reviewer suggestion, the UV vis spectroscopy image modified.

6. Line 214-215: the sentence was not completed.

As per the reviewer suggestion, the sentence has been modified.

7. Line 221: Please verify the reference to the Figure 5. It seems that Figure 4 is missing in the manuscript because the following references to figures are not corresponding to the Figures’ referenced.

As per the reviewer suggestion, the figure is verified and updated.

8. Table 4: identify the standard used.

As per the reviewer suggestion, the standard drug used for this study is mentioned in the table. 

Round 2

Reviewer 1 Report

I recommend the manuscript to accept in its present form

Reviewer 2 Report

Dear authors,

Thank you for considering my comments for revising the manuscript.

All the best.