Preparation, Characterization, Release and Antibacterial Properties of Cinnamon Essential Oil Microcapsules

Round 1

Reviewer 1 Report

The content in the manuscript entitled “Preparation, Characterization, Release and Antibacterial Properties of Cinnamon Essential Oil Microcapsules” has been intensively considered with a thorough introduction. However, the following suggestions might improve the manuscript's quality (Manuscript ID: coatings-2367279).

 

The following suggestions are:

 

In the material and methods most of the references are missing, author should add reference in an appropriate place.

 

Line # 29, Author needs to cite “As a spicy herbal medicine with a warming effect on the kidney” as well.

 

Line # 52-62, Author has not mentioned why CEO microcapsules preparation by complex coalescence method is essential and required and what are the limitations of previous methods are not clear in the manuscript.

 

Author has prepared CEO microcapsules (CMS) using a new combination of GA and HACC as wall materials. However, it is not clear whether they are immunogenic and toxic and how long it remains, and  the efficacy has not been mentioned anywhere in the manuscript, that is the study did not assess the potential toxicity of the microcapsules, which is important for their safety in food, cosmetic, and pharmaceutical applications to ensure their safety for human use.

 

Line # 487, Inhibition tests were conducted on three common bacterium and two fungus, S. aureus, E. coli, P. aeruginosa, C. albicans and A. Niger, to evaluate the inhibition effect of the core, wall, and microcapsules, respectively. However, why author has used few strains and what was the rationale behind it. Because I’m  concerned what if CMS will have good antimicrobial application in the food, cosmetic and pharmaceutical industries, how it can be clinically related and what will be the possible effect on Human gut microbiome.

The antibacterial activity of the microcapsules should have been tested against a range of bacteria to determine the effectiveness of the microcapsules against different types of bacteria.

 

The study has shown that microcapsules have potential applications in food, cosmetics, and medicine, but it does not provide any information on the specific areas of application or the advantages over existing products.

 

In vitro methods are useful for initial screening of materials; however, they do not fully represent the complex in vivo environment, which may affect the release and efficacy of the microcapsules, author should have mentioned and discussed in discussion section.

 

While the study used several techniques to characterize the microcapsules, author has  not mentioned and measured microcapsules' zeta potential, which is an important parameter that can affect the microcapsules' stability and performance.

 

Finally, the author mentions that the optimal preparation conditions were determined using different techniques like response surface methodology (RSM) and other, However, I don’t see any  statistical analysis data. The statistical analysis is important to determine the significance of the results and to ensure the reliability of the conclusions.

 

The manuscript does not discuss any limitations of the study or the areas that require further research, which would provide valuable insights to the readers. Also, author should have mentioned limitations that need to be addressed in future in discussion section.

 

 

 

 

Author Response

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Reviewer 2 Report

The authors present a study about the preparation, the characterization, the release and of Cinnamon Essential Oil Microcapsules. Their antibacterial properties have been also studied on various strains.

 

The abstract is quite complete and clear. The paper is written with an adequate format for Coatings with a subject appropriated to the scope of the journal. The references have to be also revised for a care of uniformity.

The introduction is devoted to cinnamon, cinnamon essential oil (CEO) and CEO microcapsules (CMS). Indeed, for CMS, the nature of the components is discussed as well as the preparation conditions.

The experimental part is well detailed (preparation and analytical parts i.e. FTIR TGA, DSC, …).

Considering the results, the authors described CEO microcapsules (CMS) consisting in a new combination of GA and HACC as wall materials. The effects of the temperature, pH and concentrations of starting materials have been carefully designed. Next, the response surface methodology (RSM) with Box-Behnken design (BBD) was used to explore the preparation conditions for achieving the optimal encapsulation rate of the CEO. This part is well described and helps well the reader to follow this modelling.

The morphology, the particle size, the thermal stability and the bacterial inhibition properties are given and well studied, as the slow-release behavior of CMS.

A comparison with the classically used systems is missing in terms of size, stability, biological activity, etc.

In conclusion, in this form, I recommend a minor revision of this MS for a publication Coatings.

Minor editing of English language is required.

Author Response

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Reviewer 3 Report

Dear authors,

thank you for the opportunity to review the interesting manuscript. 

My main concern is about the structure of the manuscript. It is hard to read as the discussion is mixed into the Mat/met and results part, which unnecessarily enlarges the manuscript text.

My comments are listed below:

Abstract:

Pleaserephrase the sentence 

"Chitosan quaternary ammonium salt (HACC) combined 11 with gum arabic (GA) was selected as the coated wall material for the first time. "

 

Especially "for the first time" is unclear and needs not to be mentioned in the asbtarct, as only new data should be published. 

 

Regarding results, only use clearly quantified terms and data, "good thermal stability" is not quantified. Furthermore, abstract is lacking information about statistical analysis.

 

 

L. 22: ExpDec1 is unclear and might need a definition.

L. 23: What was the control or comparison group reagrding the improved properties?

 

Introduction:

 

"warming effect on the kindey" does not sound statistically sound, as cumarin from cinnamon might be nephro-toxic.

 

L.37: "Green preservative" does not sound scientifically sound but as an advertisment phrase. Please be very strict regarding scientific language.

 

In paragraphs from Line 59-96, there are parts that rather belong to the Mat/Met or Discussion section. Please shorten the introduction accordingly.

 

L. 76: There is no defintition for an "excellent slow-release".

 

L. 97-103: This paragraph is rather a short-form of the Mat/Met section than a aim or hypothesis section. Phrase a proper, concise and short  null-hypothesis.

 

Mat/Met: 

L.111: What was the conductivity of the destilled water?

 

There are not enough informations about the test material preparations (concentrations, pH-values etc.)

 

The pragraphs in the Mat/met section containing literature references are rather discussive and should be moved. Only a brief and complete description of all experimental steps should be inlcuded in the Mat/Met section. 

 

The defintion and meaning of "bacteriostatic rate" is mentioned nowhere.

 

Results-part:

 

The results part is very hard to read, as it is not separated from the discussion poart. Please add a seperate discussion part.

The pH-treatemtn and measurement of the capsules is unclear. Please add thprough information about that to your mat/met part. 

 

The referece list is not properly formatted (capital letters)

Unquantified language as "optimal, good" is extensively used and not adequate for a scientific manuscript. 

Author Response

Please see the attachments

Author Response File: Author Response.docx