Lavender Essential Oil as Antibacterial Treatment for Packaging Paper

Round 1

Reviewer 1 Report

Thank you for the opportunity to review this paper. Namely, I find it very interesting and the topic is highly rated. The paper need language check. The manuscript is well-written and the used literature is appropriate. Still there are few things to improve:

Please, correct the following sentence from the abstract part>> In detailed five days, determination of antibacterial effectiveness of lavender treatment is determined.

In lines 137 and 208 correctly write the number of CFU/mL

How do you explain differences in the activity of Lavender EO between the tested Fusarium and Aspergillus species?

Why do you choose Saccharomyces cerevisiae for the antimicrobial tests if the plan is to form a paper with the ability of biocontroling microorganisms growth in various types of food?

How do you explain stronger antifungal activity than antibacterial activity of Lavender EO?

The discussion part is missing the correlation between EO composition and antimicrobial efficiency.

Author Response

Dear Reviewer,

We appreciate the time and effort that you have dedicated to providing valuable feedback on our manuscript, and we are grateful for your insightful comments. We have carefully considered the comments and tried our best to address every one of them.

1. Please, correct the following sentence from the abstract part>> In detailed five days, determination of antibacterial effectiveness of lavender treatment is determined.

We took this suggestion and corrected the sentence, as follows: “In detailed, five days examination is done, on the antibacterial effectiveness of lavender essential oil treatment.“

2. In lines 137 and 208 correctly write the number of CFU/mL

Thank you for this suggestion! We corrected it.

3. How do you explain differences in the activity of Lavender EO between the tested Fusarium and Aspergillus species?

 

Aspergillus brasiliensis and Fusarium moniliforme are representatives of different genera of mold fungi, which also determines the differences in the structure and physiology of their cells. This determines the different sensitivity of these microorganisms to Lavender essential oil.

We added this to the Discussion section.

 

4. Why do you choose Saccharomyces cerevisiae for the antimicrobial tests if the plan is to form a paper with the ability of biocontroling microorganisms growth in various types of food?

 

The aim of our experiments was to investigate the antimicrobial effect of lavender essential oil on the different groups of microorganisms. Saccharomyces cerevisiae together with Candida albicans are used as model yeast cell systems.

 

5. How do you explain stronger antifungal activity than antibacterial activity of Lavender EO?

 

A different activity of the essential oil was observed against the tested bacterial and fungal strains. This difference is due to the origin and composition of lavender oil, in which oxygenated terpene compounds predominate. In the lavender oil with which the present experiments were carried out, linalyl acetate predominates, which enhances the antifungal effect. From the literature (Predoi et al. 2018) it is evident that oils containing less linalyl acetate and more linalool have better antibacterial activity.

We added this to the Discussion section.

 

6. The discussion part is missing the correlation between EO composition and antimicrobial efficiency.

 

The predominant terpene compounds in the composition of lavender essential oil determine its antimicrobial activity. With the different origins of the oils, differences in the content of individual components are observed (Predoi et al. 2018; Kwiatkowski et al. 2020; Stoyanova, 2022). Therefore, lavender oil can have different effects on bacterial and fungal strains.

We added this to the Discussion section.

Author Response File: Author Response.docx

Reviewer 2 Report

Todorova et al. presented a method on using lavender essential oil as antibacterial treatment for packaging paper. Although the manuscript is well written, proper context are missing in the manuscript. Below are points of attention from this reviewer.

Point 1: Improve the sentence “Active packaging, … affects the storage if the packaged product is very …” in Line 41 – 44.

Point 2: Authors should explain why Gram-positive bacteria, Gram-negative bacteria, yeast and fungal strain are chosen over other bacteria for testing the antibacterial activity.

Point 3: Authors are advised to revise the Conclusions section. A conclusion must always start by addressing the main topic of the paper, in order to remind the reader “where it all began.” Then the next step is to briefly bring forward results previously discussed at some point in the paper, however not too extensively. The aim is to put everything on the table in order to finish the line of thought presented throughout the document. The main topic is missing in the Conclusions.

Point 4: There are some typo issues in the manuscript, such as:

- Line 29, “pathogens These”.

- Line 47, “Films films”.

- Line 101 – 105, misuse of punctuation marks. “bacterials: Gram-positive bacteria (Staphylococcus aureus ATCC 6538 and Bacillus subtilis ATCC 6633), Gram-negative bacteria (Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Salmonella abony NCTC 6017), yeast (Saccharomyces cerevisiae ATCC 2601 and Candida albicans ATCC 10231) and fungal strain (Aspergillus brasiliensis ATCC 16404 and Fusarium moniliforme)”.

Authors should read through the manuscript carefully and improve its readability.

Author Response

Dear Reviewer,

We appreciate the time and effort that you have dedicated to providing valuable feedback on our manuscript, and we are grateful for your insightful comments. We have carefully considered the comments and tried our best to address every one of them.

 

Point 1: Improve the sentence “Active packaging, … affects the storage if the packaged product is very …” in Line 41 – 44.

Correction is done, as follows: Active packaging, which, apart from its main purpose - protection, affects the storage of the packaged product. Through the newly developing technological approaches, they become a promising tool for increasing the usage of biodegradable, sustainable and natural materials and products.

Point 2: Authors should explain why Gram-positive bacteria, Gram-negative bacteria, yeast and fungal strain are chosen over other bacteria for testing the antibacterial activity.

The Gram-positive, Gram-negative bacteria, yeasts and molds used are some of the most common biological contaminants of food and were therefore chosen for the studies.

Point 3: Authors are advised to revise the Conclusions section. A conclusion must always start by addressing the main topic of the paper, in order to remind the reader “where it all began.” Then the next step is to briefly bring forward results previously discussed at some point in the paper, however not too extensively. The aim is to put everything on the table in order to finish the line of thought presented throughout the document. The main topic is missing in the Conclusions.

We strongly agree with this comment and provide a corrected version.

The lavender ЕО treatment of wrapping paper has a promising perspective for preserving products from microbial spoilage. Results indicate that wrapping paper treatment with Bulgarian lavender essential oil is successful and the antifungal effect of the obtained treated paper is more pronounced than the antibacterial one due to the linalyl acetate predominance, rather than linalool. The antimicrobial efficiency of the obtained treated paper is between 60-90% in the first two hours of the treatment and gradually decreases to 40-50% at the end of the five-day period. After the lavender EO treatment, the properties of the paper insignificant decrease, due to the additional moistening but the ability of the cellulose fibers to bond with each other is preserved and the strength is optimal for further processing. The advantages of the lavender treatment could ensure a brought application in the packaging industry, where the products are subjected to a large variety of biological contaminants.

Point 4: There are some typo issues in the manuscript, such as:

- Line 29, “pathogens These”.

- Line 47, “Films films”.

- Line 101 – 105, misuse of punctuation marks. “bacterials: Gram-positive bacteria (Staphylococcus aureus ATCC 6538 and Bacillus subtilis ATCC 6633), Gram-negative bacteria (Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Salmonella abony NCTC 6017), yeast (Saccharomyces cerevisiae ATCC 2601 and Candida albicans ATCC 10231) and fungal strain (Aspergillus brasiliensis ATCC 16404 and Fusarium moniliforme)”.

Yes, these are technical mistakes and we correct all of them.

Authors should read through the manuscript carefully and improve its readability.

We strongly agree with this comment and provide a corrected version.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have improved the quality of paper by giving answers to reviwers comments.