PROMANCOA Modular Technology for the Valorization of Mango (Mangifera indica L.) and Cocoa (Theobroma cacao L.) Agricultural Biowastes

Round 1

Reviewer 1 Report

I recommend the article  to publish.  The theme was presented in a comprehensive and reliable way. I have one remark: in figure 2, the caption under the chemical formula overlaps it.

Author Response

Thanks for your time and effort in reviewing the manuscript.  The caption in Fig. 2 will be arranged properly during the edition.

Reviewer 2 Report

The manuscript reports on valorization of Mango (Mangifera indica L.) and Cocoa (Theobroma cacao L.) as agricultural waste materials. Although it is not a novel work but includes a great number of techniques and processing technologies/unit operations for transforming waste materials from these two crops. It is worthy of investigation and publication after addressing some comments or suggestions as below:

1)L52: A brief explanation should be included for flavonoids and xanthones.

2)L82: Please double check the yield for PA antioxidant as it seems too high based on total mass of the bean.

3)Please describe all abbreviations under all tables to make it clear to the audience.

4)Please include the composition (fiber, cellulose, hemicellulose, lignin, ash, target extracts) of the raw materials/feedstocks (MSB, MBT, CPH, CBS) used as source for the extracts in this study in a table.

5)L434: Why extraction was conducted at 80C and 70 rpm? Was it optimized? How?

6)L451: Why drying was performed under such a high temperature which may degrade the products?

7)Please explain about the chemicals and analytical materials (and the sources/suppliers) used in this work under materials and methods.

8)The economic feasibility of this process should be included in the manuscript.

Author Response

Thanks for your time and effort in reviewing the manuscript.  Indeed your comments and recommendations have helped to improve the manuscript.  Regarding your contribution:

1. Indeed we were impressed but positively by the high PA content antioxidant content in the CBS extract. On the contrary, single polyphenols (catechin and epicatechin) were lower as reported in other articles.  It is a matter which deserves further investigation.
2. Our work was focused on the practical application of polyphenol-rich extracts from mango and cocoa agricultural biowastes. We did not pay attention to fiber, cellulose, and lignin-derivatives, and therefore we cannot include such table as suggested.
3. It should be considered we are reporting results of a scaling-up process in a pilot plant, after laboratory experiments (which results have been published elsewhere). Therefore, we did not conduct optimization high-cost experiments for determining extraction temperature, agitation speed, and drying temperature.  By the way, 60^oC for hot-air drying is a common practice in the extractive industry.
4. We have conducted three viability studies about PMT economic feasibility: mangiferin (90 % purity or higher) for cosmeceutical and nutraceutical formulations, MSB extract and CBS extract for nutraceuticals using the UNIDO-COMFAR software.  Because of manuscript length (20 pages), we did consider publishing those results in a separate manuscript.  Anyway, I think it is a matter of the editor’s decision.
5. As per your recommendations, we have included a paragraph + 5 references about flavonoids and xanthones, and two paragraphs + 1 reference under Materials and Methods: one with the PPC determination by UV/VIV, and the second about chemicals and standards.
6. Table legends and spelling mistakes were corrected.

Reviewer 3 Report

It's always a pleasure find articles from this group, this time it's not different. Very good work.
Nevertheless I found that some issues can be improved:
- The article is full of acronyms which make the text very difficult to read, please could you improve this fact? For example an abbreviature index could be good. Besides not all of them are developed the first time they are cited, for example DR in line 36. Please revise this point in the whole text.
- The article lacks of a Conclusion section. Please add it to summarize the main findings and remark the main strengh of the manuscript.
- The sentence in the abstract "Agricultural biowastes were processed at the Pilot Plant, National Evangelic Uni-17 versity, DR." can be ommited in the abstract, it doesn't summarize anything.
- In figure 2 the name of isomangiferin is superposed with the molecule, please separate them. Similiar effect in figure 4, please revise
- In the introduction some other valorization techniques for mango and cocoa should be addressed for example https://doi.org/10.1016/j.supflu.2019.104563 for mango and https://doi.org/10.1016/j.carbpol.2019.04.040 for cacao. In fact you can describe the advantages of PROMANCOA over those techniques in the disscussion section.

Author Response

Thanks for your time and effort in reviewing the manuscript.  Indeed your comments and recommendations have helped to improve the manuscript.  Regarding your contribution:

1. We have included the recommended citations in the introduction and eliminated the sentence from the Abstract
2. One paragraph + 4 references were added in the Discussion at the end of section 3.1 (mango).
3. One paragraph + 4 references were added in the Discussion at the end of section 3.2 (cocoa)
4. One paragraph was added in Section 5 (Conclusions)
5. Regarding abbreviations, we have followed journal instructions for authors. We did correct some mistakes and eliminate a few abbreviations when possible. Anyway, I think it is a matter of the editor’s decision.