Migration of Silver and Copper Nanoparticles from Food Coating

Round 1

Reviewer 1 Report

The authors make a careful review of the subject, having cited 124 references. The manuscript is easy to read and it is well written. However, please consider the following comments before final acceptance for publication in Coatings:

1. Abstract - is a little confused. I think it should be rewritten in the sense that the authors first make an introduction to the theme and only then outline the objectives of the work and the respective conclusions.
2. Throughout the text, numerous chemical elements and compounds are mentioned, appearing in the form of symbols, e.g.: Ag, Cu, CuO, TiO₂. The first time they appear in the text they must be written in full. Likewise, all other abbreviations must also be placed in full the first time they are mentioned in the text, such as WVTR, FDA, EFSA, among others.
3. The name of the species or of the genus when written in Latin (lines 108, 159, 160 for example), must appear written in italics. Please check and correct the entire manuscript.
4. line 430 “In another study done by Ahari and his colleagues…” the reference is missing.
5. line 298, Table 1, the table must be reviewed and standardized because some parameters are in bold others are not. Remove the last line because it is repeated. Please also remove the line above the table caption.
6. Some figures need to be improved because the legends of the graph axes cannot be clearly understood: Figure 3B, Figure 4 C (SEM image), Figure 5 D.
7. Figure 4A, it remains to be identified which Figure 4A I and which II.
8. Line 437 the phase “Size (10- 60 nm) and morphology of the AgNPs altered for the various samples. The migration of other nanoscale materials was also confirmed [89].”, it's confusing, please check and correct if necessary.
9. Line 454 I think a word is missing from the sentence “Unlike silver, the percentage of studies on the migration of CuNPs from packaging coatings to food has been done. “Please check and correct if necessary.
10. Lines 521-527 the reference is missing.
11. Line 613, “wang” capitalize.
12. standardize the references numbers 39 and 109.
13. A revision of the text is important to avoid some mistakes as in line 66 “In general, nanomaterials categorized in two groups” change to “In general, nanomaterials are categorized into two groups”, line 227 “many” change to “Many”, line237 “In another study, it was approved that …” change to “In another study, it was proved that …”, line 308 “…(TEM) and the microscope, Atomic Force Microscopy (AFM)…” change to “(TEM) and, Atomic Force Microscopy (AFM)…”

 

In my opinion, with these major revisions, the manuscript will be ready for publishing.

Author Response

Dear Editor
We highly appreciate the kindness of the reviewers and their deep and thorough comments. We are satisfied with the correctness and improvements in our paper due to the comprehensive and wisely comments from the reviewers. We have revised the present research paper in the light of their useful suggestions and comments. I hope our revision has improved the paper to the level of their satisfaction and suitable for publication. Our answers to their specific comments, suggestion, queries are finned the following.

Best Regards

Changes are highlighted in red.

 

Reviewer 1

Reconsider after major revision

Comments and Suggestions for Authors

The authors make a careful review of the subject, having cited 124 references. The manuscript is easy to read and it is well written. However, please consider the following comments before final acceptance for publication in Coatings:

1. Abstract - is a little confused. I think it should be rewritten in the sense that the authors first make an introduction to the theme and only then outline the objectives of the work and the respective conclusions.

Response: thanks for the comment. It has been corrected.

“Packaging containing nanoparticles also can increase the shelf life of products but the presence of NP may hazards human life. In this regard, there are reports regarding the side effect and cytotoxicity of nanoparticles. The main aim of this research was to study the migration of silver and copper na-noparticles from the packaging to the food matrix and assessment techniques.”

 

1. Throughout the text, numerous chemical elements and compounds are mentioned, appearing in the form of symbols, e.g.: Ag, Cu, CuO, TiO₂. The first time they appear in the text they must be written in full. Likewise, all other abbreviations must also be placed in full the first time they are mentioned in the text, such as WVTR, FDA, EFSA, among others.

Response: thanks for the comment. It has been corrected.

“As previously mentioned, various compounds can be encapsulated for food packaging purposes. Essential oils [4-6], noble metal such as Silver (Ag) [7, 8], Gold (Au) [9, 10], and also metal oxides like Copper Oxide (CuO) [11, 12], Titanium Oxide (TiO₂) [7, 13], Zinc Oxide (ZnO) [11, 14], Magnesium oxide (MgO) [15] and so on are of the well-known components in Food Packaging Systems (FPSs).”

1. The name of the species or of the genus when written in Latin (lines 108, 159, 160 for example), must appear written in italics. Please check and correct the entire manuscript.

Response: thanks for the comment. It has been corrected.

 

1. line 430 “In another study done by Ahari and his colleagues…” the reference is missing.

Response: thanks for the comment. It has been corrected.

“In another study done by Ahari and his colleagues, the migration of AgNPs into the caviar samples was also studied by the titration method and application of tetrazole with con-centrated sulphuric acid. No silver residual was reported from packages with various concentrations of AgNPs [59].”

1. line 298, Table 1, the table must be reviewed and standardized because some parameters are in bold others are not. Remove the last line because it is repeated. Please also remove the line above the table caption.

Response: thanks for the comment. It has been corrected.

Table 1. A list of common tests employed in food packaging studies.
Purpose	Tests
Shape	TEM, AFM
Size	TEM, NMR,  XRD, DLS, NTA, SEM, AFM, DCS, ICP-MS, UV-Vis, FMR
Crystal structure	XRD, HRTEM, electron diffraction, STEM
Surface area, specific surface area	liquid NMR, BET
Surface charge	Zeta potential
Size distribution	ICP-MS, DCS, DLS, NTA, FMR, DTA, TRPS, SEM
Concentration	ICP-MS, PTA, UV-Vis, RMM-MEMS,
Agglomeration state	Zeta potential, TEM, SEM, DLS, UV-Vis, Cryo-TEM,
NP Dispersion of in matrices/supports	SEM, AFM, TEM

 

1. Some figures need to be improved because the legends of the graph axes cannot be clearly understood: Figure 3B, Figure 4 C (SEM image), Figure 5 D.

Response: thanks for the comment. It has been corrected.

Fig 4

1. Figure 4A, it remains to be identified which Figure 4A I and which II.

Response: thanks for the comment. It has been corrected. It can be founded in the previous comment

 

1. Line 437 the phase “Size (10- 60 nm) and morphology of the AgNPs altered for the various samples. The migration of other nanoscale materials was also confirmed [89].”, it's confusing, please check and correct if necessary.

Response: thanks for the comment. It has been corrected.

“Size (10- 60 nm) and morphology of the AgNPs were distinct for the samples. They also confirmed the migration of other nanoscale materials [89].”

1. Line 454 I think a word is missing from the sentence “Unlike silver, the percentage of studies on the migration of CuNPs from packaging coatings to food has been done. “Please check and correct if necessary.

Response: thanks for the comment. It has been corrected.

1. Lines 521-527 the reference is missing.

Response: thanks for the comment. It has been corrected.

“It is recommended that the method of film preparation is just one of the effective reasons for migration. In one study, silver diffusion from nano-silver-polyethylene composite films into acetic acid (3%) under various migration test method was assessed to find out the effect of exposure conditions on silver release [49].”

1. Line 613, “wang” capitalize.

Response: thanks for the comment. It has been corrected.

1. standardize the references numbers 39 and 109.

Response: thanks for the comment. It has been corrected.

 

1. A revision of the text is important to avoid some mistakes as in line 66 “In general, nanomaterials categorized in two groups” change to “In general, nanomaterials are categorized into two groups”, line 227 “many” change to “Many”, line237 “In another study, it was approved that …” change to “In another study, it was proved that …”, line 308 “…(TEM) and the microscope, Atomic Force Microscopy (AFM)…” change to “(TEM) and, Atomic Force Microscopy (AFM)…”

 Response: thanks for the comment. It has been corrected. We also checked the paper and corrected the unwanted mistakes.

“till” line 538=> until, “Nan”546=> nano, “and also”55, 625, 677=> and, “AgNPS”675=> AgNPs,

 

Author Response File: Author Response.docx

Reviewer 2 Report

There is an interesting review, however, i have some questions for the author. 

1. Would the author describe more information about Cu/Ag NPs migration experiment and mechanism in the review?  
2. After Cu/Ag NPs migration, there are really safe for food? Would the author explain this?

Thank you very much!

Author Response

Dear Editor
We highly appreciate the kindness of the reviewers and their deep and thorough comments. We are satisfied with the correctness and improvements in our paper due to the comprehensive and wisely comments from the reviewers. We have revised the present research paper in the light of their useful suggestions and comments. I hope our revision has improved the paper to the level of their satisfaction and suitable for publication. Our answers to their specific comments, suggestion, queries are finned the following.

Best Regards

Changes are highlighted in red.

 

Reviewer 2

Accept after minor revision

Comments and Suggestions for Authors

 

1. Graphical abstract: Why is the word „health“ capitalized?

Response: thanks for the comment. Just to distinguish the word “health”. However it has been corrected.

1. The abbreviation of nanoparticles is not consistent (NPs vs. Nps). Also, the abbreviation NP is introduced more than once (Line 77, and 84).

Response: thanks for the comment. It has been corrected.

1. Figure 4A, scale bars are hard to read.

Response: thanks for the comment. It has been corrected.

1. Highlights: “Migration of nanoparticles are mandatory for antibacterial effects offood packaging, but it must be under “ This is not clear. For antibacterial effects this refers primarily to the migration of ions from the nanoparticles, but not the particles themselves.

Response: thanks for the comment. It has been corrected.

“Migration of nanoparticles are mandatory for antibacterial effects of food packaging, but it must be controlled to prevent hazards.”

1. One aspect that is not clear is the difference between migration of particles and migration of ions. This should be clearly distinguished and related to the aspects of nanosafety and anti-microbial activity.

Response: thanks for the comment. It has been corrected.

 

1. “There are contradictions about the effect nanoparticles embedded in food packagingsystems on human health.“ This sounds grammatically incorrect.

Response: thanks for the comment. It has been corrected.

‘There is disagreement about whether nanoparticles embedded in food packaging systems have a negative impact on human health”

1. There a several issues with words falsely capitalized: e.g. line 63: “noble” line 98 “Good” line 255 “Adsorption”, just to name a few.

Response: thanks for the comment. It has been corrected.

1. Typo: Line 564 “Ttable”

Response: thanks for the comment. It has been corrected.

 

Author Response File: Author Response.docx

Reviewer 3 Report

The manuscript by Hamed Ahari and Leila Khoshboui Larijani deals with materials for food packaging loaded with nanoparticles – a matter of profound importance. Particular attention was paid to antimicrobial effects and nano safety, in the sense of particle migration from the coating to the food. Diffusion tests and microbial growth tests are presented and discussed. The common tests employed in food packaging studies were compared and critically evaluated. The article focuses on copper and silver nanomaterials. Sadly, the presentation quality is rather poor and seems a bit unmotivated at times. In summary, I am very satisfied with the review and would recommend publication after minor revision. Even if, from my point of view, this article does not necessarily cover the core topic of the journal Coatings, I do not want to be too critical. The following list should help to improve the manuscript.

1. Graphical abstract: Why is the word „health“ capitalized?
2. The abbreviation of nanoparticles is not consistent (NPs vs. Nps). Also, the abbreviation NP is introduced more than once (Line 77, and 84).
3. Figure 4A, scale bars are hard to read.
4. Highlights: “Migration of nanoparticles are mandatory for antibacterial effects offood packaging, but it must be under “ This is not clear. For antibacterial effects this refers primarily to the migration of ions from the nanoparticles, but not the particles themselves.
5. One aspect that is not clear is the difference between migration of particles and migration of ions. This should be clearly distinguished and related to the aspects of nanosafety and anti-microbial activity.
6. “There are contradictions about the effect nanoparticles embedded in food packagingsystems on human health.“ This sounds grammatically incorrect.
7. There a several issues with words falsely capitalized: e.g. line 63: “noble” line 98 “Good” line 255 “Adsorption”, just to name a few.
8. Typo: Line 564 “Ttable”

Author Response

Dear Editor
We highly appreciate the kindness of the reviewers and their deep and thorough comments. We are satisfied with the correctness and improvements in our paper due to the comprehensive and wisely comments from the reviewers. We have revised the present research paper in the light of their useful suggestions and comments. I hope our revision has improved the paper to the level of their satisfaction and suitable for publication. Our answers to their specific comments, suggestion, queries are finned the following.

Best Regards

Changes are highlighted in red.

 

Reviewer 3

Comments and Suggestions for Authors

There is an interesting review, however, i have some questions for the author.

 

1. Would the author describe more information about Cu/Ag NPs migration experiment and mechanism in the review? 

Response: thanks for the comment. Line 287-307:

“Efforts to promote instrumentation and strategies through the analysis of foods exprienced a lack of analytical tools. This field will entails more investigation. Regulatory authorities can cause limitation on the NPs usage in foods. Invention of instruments which includes an apparatus to assess engineered NPs has been mandatory. It is important to be able in NP identification, size measurement and its distribution that must be non-invasive and unrestrictive [65]. In this approach,  a substrate covered by NPs is considered as a reference material, during combination with analytical and imaging systems, focusing on screening techniques such as mass spectroscopy (test material composition), DLS (particle size distribution),positron emission tomography (radio-tracing),  spectroscopy (NPs size), and optical emission spectrometry (trace level elemental analysis) for monitoring and collecting adequate information. Another, technique for food evaluation in viewpoint of harmful substances employs a sensor-based system included NPs in solution or nano-structured surfaces able to respond to changes in the adsorbate electronic states (chemical signal enhancement) and changes in metal roughness (electromagnetic signal enhancement) that the chemi-sorption of the analysis at the NPs surface of the bio-sensor is the main mechanism [66]. in another technique, a system to detect food safety named Raman Nano Chip™ [67] utilizes nanorods to adsorb or collect test samples under adsorption of molecules onto the nano surface structure. For more utility and applicability , sensors may be covered or coated with NPs in the form of a colloidal suspension of polymeric, metallic, or oxide NPs .”

 

1. After Cu/Ag NPs migration, there are really safe for food? Would the author explain this?

Response: thanks for the comment. Line 547-561:

“When the migration of nanoparticles occurs, the NPs penetrate into the food matrix. If the concentration of the transmitted NPs exceed the standards, this is dangerous and hazards human life. In this case, it does not matter whether the presence of NPs is safe for the food or not. In cases where the concentration of migratory NPs is below the standard, on the one hand, there is no danger to human health, and on the other hand, NPs prevent the growth of microorganisms and fight bacteria. However, studies have shown that NPs are now present in many processed and natural foods, and new types of NPs may be used as functional materials in the future by the food industry, including packaging. Many of these NPs are thought to affect human health, and there is evidence that some of them could have detrimental effects and need further study. Further studies are also needed on the negative effects of NPs on food itself [117]. It is hypothesized that the presence of NPs may react with water, oxygen, fats, carbohydrates, minerals, and proteins within the food matrix. Although there are some food-grade NPs, but the final products may hazards the human life, thereby more studies are required to answer this question in details..”

 

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors made all the suggested changes, significantly improving the manuscript. So, in my opinion, the manuscript is ready to be accepted for publication.