Olive Leaves Extract from Algerian Oleaster (Olea europaea var. sylvestris) on Microbiological Safety and Shelf-life Stability of Raw Halal Minced Beef during Display

Round  1

Reviewer 1 Report

This paper describes the antimicrobial and antioxidant effects of Algerian olive leaves extract on raw “Halal” minced beef in a satisfactory way. The work is interesting, informative and well-organized. I only have some observations that are listed in the following lines.

1.       Title is too long. Consider rewriting.

2.       Line 22: … had significant ….

3.       Line 25: … stability pathways.

4.       Line 39: …. immigrants and for…

5.       Lines 37-45: provide a reference.

6.       Line 46-48: Do you have a reference for the statement on olive being the first mentioned plant? If not, this statement should be replaced with “The olive tree (Olea europeaea, Oleaceae) is one of the plants mentioned in Holy Quran”. Also, “الأمين" does not translate into “prosperous”. It’s either “safe” or “secure”.  Remove the exclamation mark and add the number of each verse (ayah).

7.       Line 48: “...and provided huge economic”, rewrite in a new sentence.

8.       Line 52: “In herbal medicine, the effect of olive leaves is attributed in whole or in part to 53 their phenolic compounds.” Provide a reference.

9.       Line 56: ... or neurodegenerative diseases…

10.   Line 65: A grammatical mistake.

11.   Line 68: The sentence started with “several works…”, cite them.  

12.   Line 71: provide a reference.

13.   Line 80: The figure should be “Figure 2” not “Figure 3”. The caption needs to be more descriptive and informative.

14.   Line 83: The leaves were collected during the period of February 2010-2012. Why the leaves were collected on 2 years? How many collections were performed? Were all the leaves mixed into a single patch?

15.   Line 84-87: Several grammatical mistakes.

16.   Line 92: The figure should be “Figure 3” not “Figure 2”. Use letters to distinguish the pictures.

17.   Line 93: when was the extraction performed?

18.   Line 97-99: This part is not clear. The solvent in the supernatant was evaporated then filtered? Please clarify.

19.   Line 103: Avoid starting the sentence with a number that is not written out.

20.   Line 118: What is meant by “the gradient program was achieved.”? Mention the gradient used.

21.   Line 119: …flow rate…

22.   Line 141: Application…

23.   Line 154: A grammatical mistake.

24.   Line 196: … Halal minced beef.

25.   Line 212: “three independent experiments conducted at least in triplicate…”, if I understood this statement correctly, each experiment was repeated at least 9 times. Is that correct?

26.   Line 237: The information in Table 1 is repetition of what is already mentioned in the text (lines 221 and 288)

27.   Line 254: … presented in Table 3.

28.   Line 273: Table 3 could be simply presented as a figure containing all the structures. Chemical structure is different from chemical formula. Since some structures are shaky and of varying qualities, it would be better to redraw the structures using the same program.

29.   Line 287: A grammatical mistake.

30.   Line 302: …. may act as good hydrogen (H) donation?

31.   Line 321: rewrite

32.   Lines 393-399 are citing work on virgin olive oil not leaf extract. Explain.

33.   Line 446: rewrite

34.   Line 451-453: provide a reference.

35.   Figure 7: The numbers on the Y-axis should not contain a comma.

36.   The discussion part needs to be extended.

37.   Add the appropriate funding source.

Author Response

Response to Reviewer 1 Comments

Point 1: Title is too long. Consider rewriting. 


Response 1: the title is changed

Point 2: Line 22: … had significant ….

Response 2: It’s corrected

Point 3: Line 25: … stability pathways.

Response 3: It’s corrected

Point 4: Line 39: …. immigrants and for…

Response 4: It’s corrected

Point 5: Lines 37-45: provide a reference.

Response 5: The reference is added

Point 6: Line 46-48: Do you have a reference for the statement on olive being the first mentioned plant? If not, this statement should be replaced with “The olive tree (Olea europeaea, Oleaceae) is one of the plants mentioned in Holy Quran”. Also, “الأمين" does not translate into “prosperous”. It’s either “safe” or “secure”.  Remove the exclamation mark and add the number of each verse (ayah).

Response 6: It’s corrected

Point 7: Line 48: “...and provided huge economic”, rewrite in a new sentence.

Response 7: It’s corrected     

Point 8: Line 52: “In herbal medicine, the effect of olive leaves is attributed in whole or in part to their phenolic compounds.” Provide a reference.

Response 8: The reference is added

Point 9:  Line 56: ... or neurodegenerative diseases…

Response 9: It’s corrected

Point 10: Line 65: A grammatical mistake.

Response 10: It’s corrected

Point 11: Line 68: The sentence started with “several works…”, cite them.  

Response 11: The references are added

Point 12: Line 71: provide a reference.

Response 12: The references are added

 Point 13: Line 80: The figure should be “Figure 2” not “Figure 3”. The caption needs to be more descriptive and informative.

Response 13: It’s corrected

 Point 14: Line 83: The leaves were collected during the period of February 2010-2012. Why the leaves were collected on 2 years? How many collections were performed? Were all the leaves mixed into a single patch?

Response 14: The leaf samples were collected on 3 occasions, during the period of February 2010, 2011 and 2012. The collected leaves were those obtained after the washing and the cleaning of the olives at their entrance in the oil mill. For this, results were presented as the means of three independent experiments.

 Point 15: Line 84-87: Several grammatical mistakes.

Response 15: It’s corrected

 Point 16: Line 92: The figure should be “Figure 3” not “Figure 2”. Use letters to distinguish the pictures.

Response 16: It’s corrected.

 Point 17: Line 93: when was the extraction performed?

Response 17: During the experimental period from 2010-2012 (2010, 2011 and 2012)

Point 18: Line 97-99: This part is not clear. The solvent in the supernatant was evaporated then filtered? Please clarify.

Response 18: It’s corrected

- The clear supernatant was obtained after evaporation of the solvent by rotary evaporator under vacuum at 40 ºC, the obtained supernatant was then filtered (filters of 0.45 mm), who represents the olive leaves extract.

Point 19: Line 103: Avoid starting the sentence with a number that is not written out.

Response 19: It’s corrected

Point 20:    Line 118: What is meant by “the gradient program was achieved.”? Mention the gradient used.

Response 20: It’s corrected

Point 21: Line 119: …flow rate…

Response 21: It’s corrected

Point 22: Line 141: Application…

Response 22: It’s corrected

Point 23: Line 154: A grammatical mistake.

Response 23: It’s corrected

Point 24: Line 196: Halal minced beef.

Response 24: It’s corrected

Point 25: Line 212: “three independent experiments conducted at least in triplicate…”, if I understood this statement correctly, each experiment was repeated at least 9 times. Is that correct?

Response 25: Yes, it’s correct. They are three experiments with three repetitions for each measured attribute for each experiment.

Point 26: Line 237: The information in Table 1 is repetition of what is already mentioned in the text (lines 221 and 288)

Response 26: It's just to describe the results obtained for total phenol content and free-radical scavenging activity. Moreover it is the same case as the other Tables.

Point 27: Line 254: … presented in Table 3.

Response 27: It’s corrected

Point 28: Line 273: Table 3 could be simply presented as a figure containing all the structures. Chemical structure is different from chemical formula. Since some structures are shaky and of varying qualities, it would be better to redraw the structures using the same program.

Response 28: It’s corrected

Point 29: Line 287: A grammatical mistake.

Response 29: It’s corrected

Point 30: Line 302: …. may act as good hydrogen (H) donation?

Response 30: It is one of the antioxidant mechanisms of polyphenols extracted from olive leaves (e.g. the hydrogen-donor ability of natural antioxidants in olive oil decreases as follows: hydroxytirosol, oleuropein…..[c.f. Roche M., Dufour C., Mora N. et. al. Antioxidant activity of olive phenols: mechanistic investigation and characterization of oxidation products by mass spectrometry. Org. Biomol. Chem. 2005. v. 3, p. 423–430.].

Point 31: Line 321: rewrite

Response 31: the sentence is corrected

Point 32: Lines 393-399 are citing work on virgin olive oil not leaf extract. Explain.

Response 32: We just want to compare the antimicrobial activity of polyphenols from olive tree (e.g. virgin olive oil) against the same specie of bacteria (Salmonella enterica ser. Enteritidis). We think these results could be comparable.

Point 33: Line 446: rewrite

Response 33: The sentence is corrected

Point 34: Line 451-453: provide a reference.

Response 34:  It is a real and practical fact for some Maghreb origin butchers.

- The references are added

Point 35: Figure 7: The numbers on the Y-axis should not contain a comma.

Response 35: It’s corrected

Point 36: The discussion part needs to be extended.

Response 36: Our manuscript exceeds the 9700 words. For this reason we have preferred not to extend too much in the discussion parts.

Point 37: Add the appropriate funding source.

Response 37: It’s added

Author Response File: Author Response.docx

Reviewer 2 Report

The experiment and results obtained are worth and useful, but the way of their presentation here is not acceptable. Therefore, I suggest to the authors to pay much more attention to some very important points and eventually resubmit it in a different form.

I am highlighting here some very big lacks the authors should work on.

1) Latin names

- Latin names of plant/microorganism species should always be written according to the scientifically-recognized way, and there are a way too much mistakes in the whole document in that sense;

- some of the most important guidelines are following: Latin name is always in italic, Latin name is always written in the way that the 1st word (genus) is a capital letter and the 2nd one is not; names of subspecies, variety, serotype etc. are also following this rule, but when it comes to the microorganisms - there is some exceptions, and I suggest to check it in the reference: Brenner FW, Villar RG, Angulo FJ, Tauxe R, Swaminathan B. Salmonella nomenclature. J Clin Microbiol. 2000, 38(7);

2) Nomenclature

- double check taxonomic status of Olea species you used: is it a variety, or even different species?

- putting the author's name (L.) after the species name (O. europea) should be in the whole document or never,

- taxonomy status should be determined in accordance with a relevant regional Flora (not the national one) and it should be clearly highlighted in the paper;

- the name of the botanist who identified it should be also clearly highlighted;

- the importance of these points is huge, and actually crucial for the relevance of your results as well as the way of comparing your results with the literature (somewhere you write about O. europea and compare it with your ''wild relative'', somewhere the difference is not mentioned, and that is all very confusing and very hard-to-follow by a reader);

3) Abbreviations

- it is completely unacceptable use them in a random way, especially when it comes to ''OLE'' and ''sylv.OLE'' since that makes the paper very confusing,

- mentioning microorganisms/plants for the first time in the paper, even citing the data from another (literature) sources, should never be in the way of abbreviation,

4) English

- submitting a paper in this form is unacceptable since it is very incomprehensible,

- English language proofreading is necessary.

Author Response

Response to Reviewer 1 Comments

The experiment and results obtained are worth and useful, but the way of their presentation here is not acceptable. Therefore, I suggest to the authors to pay much more attention to some very important points and eventually resubmit it in a different form. 


Point 1: Latin names of plant/microorganism species should always be written according to the scientifically-recognized way, and there are a way too much mistakes in the whole document in that sense.

Response 1: Latin names of plant/microorganism species are corrected and written according to the scientifically-recognized way.

Point 2: some of the most important guidelines are following: Latin name is always in italic, Latin name is always written in the way that the 1st word (genus) is a capital letter and the 2nd one is not; names of subspecies, variety, serotype etc. are also following this rule, but when it comes to the microorganisms - there is some exceptions, and I suggest to check it in the reference: Brenner FW, Villar RG, Angulo FJ, Tauxe R, Swaminathan B. Salmonella nomenclature. J Clin Microbiol. 2000, 38(7).

Response 2: Latin names of microorganism species are corrected and written according to the scientifically-recognized way

Point 3: double check taxonomic status of Olea species you used: is it a variety, or even different species?

Response 3: The taxonomic status of Olea species is corrected in the text.

Point 4: putting the author's name (L.) after the species name (O. europea) should be in the whole document or never.

Response 4: OK. It’s corrected

Point 5: taxonomy status should be determined in accordance with a relevant regional Flora (not the national one) and it should be clearly highlighted in the paper.

Response 5: OK. It’s corrected.

Point 6: the importance of these points is huge, and actually crucial for the relevance of your results as well as the way of comparing your results with the literature (somewhere you write about O. europea and compare it with your ''wild relative'', somewhere the difference is not mentioned, and that is all very confusing and very hard-to-follow by a reader.

Response 6: The text is corrected and the confusion is removed.

Point 7: it is completely unacceptable use them in a random way, especially when it comes to ''OLE'' and ''sylv.OLE'' since that makes the paper very confusing.

Response 7: The text is corrected and the confusion is removed.

Point 8: mentioning microorganisms/plants for the first time in the paper, even citing the data from another (literature) sources, should never be in the way of abbreviation

Response 8: OK. It’s corrected.

Point 9:   English language proofreading is necessary.

Response 9: English is highly corrected.

Author Response File: Author Response.docx

Round  2

Reviewer 1 Report

The authors have made most of the recommended changes. The paper is greatly improved.

Author Response

Dear

We would be happy to consider a revision of our manuscript “very improved version”.

Best regards

Sincerely,
Pr. Dr. Djenane D.

Author Response File: Author Response.docx

Reviewer 2 Report

I would like to thank to the authors for taking my suggestions into consideration and for adapting the paper in that way. 

However, I would kindly ask for one more thing: conclusion part. I am not sure why they wrote ''OLE from oleaster''? Additionally, I suggest to make some extra points from their results and highlight them as a conclusion: e.g. what are the main chemical constituents. Although it has been already given in Abstract, it is useful to be mentioned in Conclusion as well. 

Author Response

Dear

Thank you very much for your valuable  suggestions.

We would be happy to consider a revision of our manuscript “very improved version”.

 Best regards

Sincerely,

Pr. Dr. Djenane D.

Author Response File: Author Response.docx