The Potential Use of Citrus aurantifolia L. Essential Oils for Decay Control, Quality Preservation of Agricultural Products, and Anti-Insect Activity

Round 1

Reviewer 1 Report

The presented results are interesting and presented in an informative and clear way. The research and goal is also interesting. The reviewer has a few general questions and doubts.

1. Why was only one oil tested?

It is known that oils from different sources, even if obtained in the same way and from the same species (varieties), can give different results. The reviewer suggests using several oils from different companies in the next research, and even try to obtain your own oil. 2. What was the basis for the selection of agricultural products in the research? Probably other literature research? So please describe the scientific novelty in the publication.

3. What is the application purpose of lemon oil.

Unfortunately, despite the global activity, it will be difficult to use it due to the aroma. Please indicate the authors' idea for the use of this oil and enter it in the application.

Material and Methods

Based on the description of the methodology, it is difficult to read the results. Please complete the methodology with general details, taking into account the description of the model, etc.

Chapter Material and methods, first the material, describe it in points, and then the methods used.

Please explain why such bacteria any yeast were selected for microbiological tests

The names of microorganisms should be completed in the test methodology

Results

The results are clearly presented.

Table 4 please correct the table graphics, there are no lines in some places

Conclusions

Please correct the conclusions. They are mainly a summary of research and observations. The conclusions are relevant to the purpose of the work.

Author Response

Reviewer 1:

The presented results are interesting and presented in an informative and clear way. The research and goal is also interesting. The reviewer has a few general questions and doubts.

1. Why was only one oil tested?

It is known that oils from different sources, even if obtained in the same way and from the same species (varieties), can give different results. The reviewer suggests using several oils from different companies in the next research, and even try to obtain your own oil. 

Response: Thank you for your feedback. But only one essential oil from Hanus s.r.o. was analyzed. Our work was focused on evaluating the biological activity of the essential oil from Hanus. It was not the intention of the work to analyze essential oils from several manufacturers.

2. What was the basis for the selection of agricultural products in the research? Probably other literature research? So please describe the scientific novelty in the publication.

Response: We chose these agricultural products because they are relatively often grown and stored products in our area. A novelty in our work is the monitoring of the biological effect of the essential oil from the Hanus company, which has not been evaluated yet. Also, the steam application of this essential oil has not been studied.

3. What is the application purpose of lemon oil.

Unfortunately, despite the global activity, it will be difficult to use it due to the aroma. Please indicate the authors' idea for the use of this oil and enter it in the application.

Response: As we state in the conclusions of our work, the application of essential oil could be the application of steam when extending the shelf life or protecting agricultural products. The high insecticidal activity offers the possibility of future use for the preparation of natural insecticidal, larvicidal, or repellent preparations. As for the aroma of essential oil, our results show that low concentrations are needed, which should not affect the sensorics.

Material and Methods

Based on the description of the methodology, it is difficult to read the results. Please complete the methodology with general details, taking into account the description of the model, etc.

Chapter Material and methods, first the material, describe it in points, and then the methods used.

Response: Thanks for your feedback. The Material and methods section has been described in more detail.

Please explain why such bacteria any yeast were selected for microbiological tests

Response: A. chroococum is one of the bacteria found in soil and water. Therefore, it can occur on agricultural products. In the soil, its presence is exerted due to the ability to fix atmospheric nitrogen. Once harvested, its presence is no longer necessary and could lead to spoilage of the products during storage.

1. marscescens is highly resistant to antibiotics and causes many diseases in humans. Its naturalness is also observed on larvae, insect pupae as well as on foods with a higher proportion of starch and sugars. It also causes gourd disease of the yellow vine.
2. megaterium is a suitable model microorganism for studying the effect against gram-positive microorganisms. It belongs to the widespread species.
3. luteus occurs in a variety of environments, including soil, and can cause damage to stored products.
4. tropicalis and C. glabrata often occur on the surface of various fruits and can cause many diseases in humans as well as degrade agricultural products.

The names of microorganisms should be completed in the test methodology

Response: The microorganisms tested are listed in section 2.4.

Results

The results are clearly presented.

Table 4 please correct the table graphics, there are no lines in some places

Response: Thank you very much for your opinion. The table has been modified.

Conclusions

Please correct the conclusions. They are mainly a summary of research and observations. The conclusions are relevant to the purpose of the work.

Response: Some sentence was deleted and changed.

Reviewer 2 Report

To the Authors (in detail):

• In the title insert the abbreviation of the botanist;
• Abstract section, please insert some numeric relevant value;
• Introduction section, page 2, line 52, after your ref 8. This section has to be improved, you have to explain that the essential oil composition of a part of a plant is influenced by many factors such as: environment [X1]; harvest year [X2]; cultivar [X3]; geographical area of cultivation [X4, X5], essential oil extraction system [X6],  …..and so on. Support this statement, at least, with the following references, … please write the reference number after each variable and do not cumulate the references number at the end of the sentence:

[X1] Effect of Environmental Conditions on the Yield of Peel and Composition of Essential Oils from Citrus Cultivated in Bahia (Brazil) and Corsica (France)

Agronomy 2020, 10, 1256; doi:10.3390/agronomy10091256

[X2] The peel essential oil composition of bergamot fruit (Citrus bergamia, Risso) of Reggio Calabria  (Italy): a review.

Emirates Journal of Food and Agriculture 32 (11) 835-845 (2020)

doi: 10.9755/ejfa.2020.v32.i11.2197

[X3] Citrus bergamia, Risso: the peel, the juice and the seed oil of the bergamot fruit of Reggio Calabria (South Italy).

Emirates Journal of Food and Agriculture 32(7) 522-532 (2020).

DOI: 10.9755/ejfa.2020.v32.i7.2128

[X4] Citrus lemon essential oil: chemical composition, antioxidant and antimicrobial activities with its preservative effect against Listeria monocytogenes inoculated in minced beef meat. Lipids in Health and Disease (2017) 16:146 DOI 10.1186/s12944-017-0487-5

[X5] Chemical composition and antimicrobial potency of locally grown lemon essential oil against selected bacterial strains.

Journal of King Saud University – Science (2018) 30, 14–20.

http://dx.doi.org/10.1016/j.jksus.2016.08.008

 [X6] Cold Pressing, Hydrodistillation and Microwave Dry Distillation of Citrus Essential Oil from Algeria: A Comparative Study.

Electronic Journal of Biology, 2016, Vol.S1: 30-41

• 2.1 section, please include information about: type of soil, microclimate, age of plants, degree of ripening of fruits, cultivation conditions (fertilizers, irrigation, pest treatments, and so on);
• 2.1 sub-section: from which region of Italy?
• 2.1 sub-section, describe carefully the essential oil extraction system;
• 2.1 sub-section, indicate the year of essential oil production and the year of analysis;
• 2.2 sub-section if you have used only the library to indentify the compounds you have to specify that your procedure is a tentative identification, if not, please detail the applied method;
• 2.9 sub-section p < 0.05, in the captions of table p ≤ 0.05, please, verify and be consistent in the whole manuscript;
• Caption of tables, please specify if statistical analysis in considered vertically or horizontally;
• Discussion section, line 187 and in the tables, when you have indicated p (para) sometime was italicized and sometime not, please, be consistent in the whole manuscript;
• Discussion section, line 189: in the large part of your manuscript you have written the names of compounds in small letter, here you have written Terpinene in capital letter, please be consistent. The same for gamma or as a letter of the ancient Greek alphabet; see also beta-Pinene. Verify the whole manuscript and compare with your table 1;
• Discussion section, lines 192-193, here and in other parts of this manuscript the references are not correctly included, please, verify carefully each reference;
• Discussion section, line 196, when the authors of the cited paper are two, you have to include both, in this case: Hojjati and Barzegar;
• Discussion section, lines 196-197 and in the whole manuscript, verify the English form. Re write this sentence,
• References section, references 1, 7, 8, 22, 23, 24, 25, 27… and in the whole section, please, use the binomial nomenclature to write the scientific names: the specie in small letter: aurantifolia and not Aurantifolia;
• References section, references 26, 32, 38 please, use the binomial nomenclature to write the scientific names: the specie in small letter: Citrus limon and not Citrus Limon;
• References section, reference 37 please, use the binomial nomenclature to write the scientific names: the specie in small letter: Allium sativum and not Allium Sativum;
• Please, very important, write in blue color or evidence differently the corrections you will do.

I suggest a major revision

Regards.

Author Response

Reviewer 2:

To the Authors (in detail):

In the title insert the abbreviation of the botanist;

Response: Thanks for the advice. The abbreviation botany was added to the name.

Abstract section, please insert some numeric relevant value;

Response: Thanks for the comment. Numerical data were added to the abstract.

Introduction section, page 2, line 52, after your ref 8. This section has to be improved, you have to explain that the essential oil composition of a part of a plant is influenced by many factors such as: environment [X1]; harvest year [X2]; cultivar [X3]; geographical area of cultivation [X4, X5], essential oil extraction system [X6],  …..and so on. Support this statement, at least, with the following references, … please write the reference number after each variable and do not cumulate the references number at the end of the sentence:

[X1] Effect of Environmental Conditions on the Yield of Peel and Composition of Essential Oils from Citrus Cultivated in Bahia (Brazil) and Corsica (France)

Agronomy 2020, 10, 1256; doi:10.3390/agronomy10091256

[X2] The peel essential oil composition of bergamot fruit (Citrus bergamia, Risso) of Reggio Calabria  (Italy): a review.

Emirates Journal of Food and Agriculture 32 (11) 835-845 (2020)

doi: 10.9755/ejfa.2020.v32.i11.2197

[X3] Citrus bergamia, Risso: the peel, the juice and the seed oil of the bergamot fruit of Reggio Calabria (South Italy).

Emirates Journal of Food and Agriculture 32(7) 522-532 (2020).

DOI: 10.9755/ejfa.2020.v32.i7.2128

[X4] Citrus lemon essential oil: chemical composition, antioxidant and antimicrobial activities with its preservative effect against Listeria monocytogenes inoculated in minced beef meat. Lipids in Health and Disease (2017) 16:146 DOI 10.1186/s12944-017-0487-5

[X5] Chemical composition and antimicrobial potency of locally grown lemon essential oil against selected bacterial strains.

Journal of King Saud University – Science (2018) 30, 14–20.

http://dx.doi.org/10.1016/j.jksus.2016.08.008

[X6] Cold Pressing, Hydrodistillation and Microwave Dry Distillation of Citrus Essential Oil from Algeria: A Comparative Study.

Electronic Journal of Biology, 2016, Vol.S1: 30-41

Response: Thank you for your inspiring comment and the references offered to complete the section. The section was supplemented by the resources you provided.

2.1 section, please include information about: type of soil, microclimate, age of plants, degree of ripening of fruits, cultivation conditions (fertilizers, irrigation, pest treatments, and so on);

2.1 sub-section: from which region of Italy?

2.1 sub-section, describe carefully the essential oil extraction system;

2.1 sub-section, indicate the year of essential oil production and the year of analysis;

Response: The essential oil was purchased from the commercial company Hanus s.r.o. However, we do not have more detailed data on cultivation, origin, and extraction method. All data provided by the manufacturer are listed.

2.2 sub-section if you have used only the library to indentify the compounds you have to specify that your procedure is a tentative identification, if not, please detail the applied method;

Response: The section has been described in more detail.

2.9 sub-section p < 0.05, in the captions of table p ≤ 0.05, please, verify and be consistent in the whole manuscript;

Response: Thank you very much for the warning was unified.

Caption of tables, please specify if statistical analysis in considered vertically or horizontally;

Response: It was added under the individual tables that these are differences between concentrations.

Discussion section, line 187 and in the tables, when you have indicated p (para) sometime was italicized and sometime not, please, be consistent in the whole manuscript;

Discussion section, line 189: in the large part of your manuscript you have written the names of compounds in small letter, here you have written Terpinene in capital letter, please be consistent. The same for gamma or as a letter of the ancient Greek alphabet; see also beta-Pinene. Verify the whole manuscript and compare with your table 1;

Response: Thanks for the alert. It has been repaired and unified.

Discussion section, lines 192-193, here and in other parts of this manuscript the references are not correctly included, please, verify carefully each reference;

Response: Thanks for the alert. It has been fixed.

Discussion section, line 196, when the authors of the cited paper are two, you have to include both, in this case: Hojjati and Barzegar;

Response: Thanks for the alert. It has been fixed.

Discussion section, lines 196-197 and in the whole manuscript, verify the English form. Re write this sentence,

Response: Thanks for the comment. The sentence has been rewritten.

References section, references 1, 7, 8, 22, 23, 24, 25, 27… and in the whole section, please, use the binomial nomenclature to write the scientific names: the specie in small letter: aurantifolia and not Aurantifolia;

References section, references 26, 32, 38 please, use the binomial nomenclature to write the scientific names: the specie in small letter: Citrus limon and not Citrus Limon;

References section, reference 37 please, use the binomial nomenclature to write the scientific names: the specie in small letter: Allium sativum and not Allium Sativum;

Response: Thanks for the alert. Names have been modified.

Please, very important, write in blue color or evidence differently the corrections you will do.

I suggest a major revision

Round 2

Reviewer 2 Report

The Authors have included all my comments. The manuscript is interesting, the experiment is well designed and described. The discussion is well conducted.

Regards.