Effect of Nanostructured Chitosan/Propolis Coatings on the Quality and Antioxidant Capacity of Strawberries During Storage

Round 1

Reviewer 1 Report

The manuscript “Effect of nanostructured chitosan / propolis coatings on the quality and antioxidant capacity of strawberries during storage” by Martínez-González et al. studies the feasibility of coating strawberries with a combination of chitosan nanoparticles and propolis to extend their self-life.

This manuscript is well structured and written. The experimental design proposed in the manuscript allows the authors to respond to their objectives. This paper describes the results derived from well-designed experiments.

Nevertheless, the authors should make several changes before getting their manuscript accepted for publication. The comments from the reviewer are listed below:

 

KEYWORDS

The authors should avoid using abbreviation as keywords (TSS)

 

They should choose more specific keywords

 

INTRODUCTION

In the introduction, the authors should reduce examples of previous studies. There is some detailed information on the results of specific previous studies. This information could be included in the discussion section. On the other hand, the introduction should give a general background on the literature about the topic they are investigating expanding the information about nanoparticles from chitosan.

 

MATERIAL AND METHODS

How the authors verified the size of the nanoparticles produced? There is no information on the quality assessment of these particles, which can have a significant impact on the results.

 

The authors should be consistent when using units’ nomenclature (i.e., µl vs. µL – among other examples).

 

The use of CIELAB color values although quantitative does not give a visual idea of color changes. The reviewer recommends to include squares of color (transforming CIELAB values to RGB values) to give a more natural sight of the results. Check https://doi.org/10.1016/j.foodres.2017.11.009

 

Line 119, change to total phenolic compounds

 

Line 128, change “To quantify the flavonoids” to “To quantify flavonoids” or “To quantify the flavonoid content.”

 

 

RESULTS AND DISCUSSION

The authors should use only one decimal number when using percentages.

 

A statistical analisis should be run to compare the evolution of the samples within the experimental time. Results should be included as subscript letters (z, y, x …)

 

Figure 1 should include statistical information (both in the figure and the caption). The number of replicates should be indicated in the caption along with the explanation of results (i.e., results were expressed as mean ± SD)

 

In general, Al tables and figures should include the statistical information, including the manner of expressing the results, the number of experimental replicates, and the statistical design used.

 

Tables 3, 4, and 5 could be converted intp a Figure with 3 subsections and include the color squares previously indicated in the fourth one.

 

The in vitro antioxidant capacity expressed as a percentage is not a very reliable unit since it cannot be compared due to its dependence on the initial concentration of DPPH. Instead, using Trolox equivalents is a more consistent way of doing it. Hence, the referee recommends running an experiment with Trolox and recalculate the results as Trolox equivalents.

 

CONCLUSIONS

The authors might obtain a final conclusion from their results in addition to summarizing them.

 

FINAL COMMENT

As it is, this manuscript is not ready to be published in Coatings. The authors should perform some experiments, calculations, and rewrite some parts of the manuscript to have their paper reconsidered for publication.

 

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Interesting article, but some major problems need to be solved before to be accepted for publication

1. In Fig 1 - you have translate in English the data from axes - dia-days
2. in Fig. 1 - clarify which one is the initial/reference day - is day 1 or day 0? The design of the experiment and the figure are unclear.
3. page6 line 198 - in the state if "hydrogen groups" - "hydrogen atom"
4. Replace ml with - mL
5. Formula from the lines 144-146 - need to be rewritten - it is unclear
6. More discussions are needed in order to compare the obtained results with other existing data
7. Drawbacks of the study need to be mentioned
8. Cost related procedures need to be underlined in the article
9. The conclusion needs to be rewritten in order to underline the originality of the study -newly added data need to be underlined

 

 

Author Response

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Reviewer 3 Report

The subject have an innovative charachter but the quality of presentation should be implemented.

At line 56 some lines on nanostructured compounds should be added.

The aim of work should be clarified.

In Material and Methods some lines on definition and updated status on approach on antioxidant properties should be given and related references should be added: Durazzo and Lucarini. A current shot and re-thinking of antioxidant research strategy.Brazilian Journal of Analytical Chemistry 5(20), pp. 9-11.

The limits and advantages of this research as well as practical applications should be marked in Conclusion.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

The authors answered to almost all of the reviewer's questions

Author Response

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