Review Reports

Round 1

Reviewer 1 Report

Title: “Antimicrobial and Odour Qualities of Alkylpyrazines Occurring in Chocolate and Cocoa Products”

In this review article written by Cherniienko et al., the authors have collected the antibacterial properties data of alkylpyrazines'. 40 Pyrazine compounds of cocoa and chocolate were discovered through literature analysis. From this data, the authors have found that 12 substances were effective against bacteria, fungus, and oomycete. In this review first, the authors have given concise introduction about cocoa and chocolate products. Then they focused on pyrazines in chocolate and cocoa, including detection of alkylpyrazines in cocoa and chocolate. In this section the authors have given the aroma profile of the 40 pyrazines found in cocoa and chocolate. Later, the authors have discussed the antimicrobial activity of pyrazines, which include antibacterial activity, antifungal and anti-oomycete activity, structure activity relationship of alkylpyrazines. Also, they discussed the quantification of the impact of alkylpyrazine compounds on the aroma of cocoa and chocolate. Finally, they discussed on relationship between odour and antimicrobial activities of pyrazines. The authors have also performed statistical evaluation of the correlation between the odour threshold and the probability of antibacterial activity. In Figure 1, the structures are not good, authors should redraw the structures in latest ChemDraw software. Overall, the review was well written, and all the references are in proper format. This review article can be published in “Applied Sciences” without any revision.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

Dear Editor

The manuscript enriches our knowledge concerning the presence of pyrazine compounds in cocoa and chocolate and looks like a literature survey
The work appears to be integrated into its construction and the results deduced regarding the investigation of the correlation between aroma and the antibacterial capabilities of alkyl pyrazines.
I have only an inquiry (How was built the orthonasal profile of alkyl pyrazines in cocoa and dark chocolate and the other ingredients? It is only an inquiry. Is there a program to build that profile? In this case, it should be mentioned.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The authors studied the antimicrobial and Odour Qualities of Alkylpyrazines Occur- 2 ring in Chocolate and Cocoa Products. It is important mainly for countries that have a food program based on these products. 

My minor suggestion: The introduction is short. it can be improved using more recent studies.

The section 'The Way of Formation of Pyrazine in Cocoa and Cocoa Products' is so long and boring. The author can separate it into some sub-sections.

For the section ' Relationship between Odour and Antimicrobial Activities of Pyrazines', the authors used just a reference. Such a main subject needs more potent references. Otherwise, this section should be deleted.

Why the authors used references in their conclusion? 

Author Response

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Author Response File: Author Response.docx